EP2425039A2

EP2425039A2 - Method for preparing a metallised substrate, the resulting substrate and the uses thereof

Info

Publication number: EP2425039A2
Application number: EP10718154A
Authority: EP
Inventors: Thomas Berthelot; Pascal Viel; Alexandre Garcia; Sébastien ROUSSEL
Original assignee: Commissariat a lEnergie Atomique CEA; Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Current assignee: Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Priority date: 2009-04-30
Filing date: 2010-04-30
Publication date: 2012-03-07
Also published as: JP5654570B2; EP2424928A1; WO2010125189A2; FR2944982B1; CN102414343A; US20100311857A1; US20100323119A1; WO2010125190A1; WO2010125191A2; US20100310800A1; EP2424926A2; FR2944982A1; WO2010125191A3; EP2424928B1; FR2945045B1; US9453284B2; KR20120017054A; JP2012525462A; FR2945045A1; FR2945046A1

Abstract

The invention relates to a method for preparing a metallised substrate, comprising the following steps consisting in: grafting a polymer-type compound to the substrate, said compound optionally having a group capable of chelating at least one metal ion; bringing the aforementioned compound, which is capable of chelating at least one metal ion, into contact with at least one metal ion, exposing said polymer-type compound to conditions that allow the reduction of the chelated metal ion(s) and repeating the chelation/reduction steps until a metallised substrate is obtained. The invention also relates to the resulting substrates and to the uses thereof.

Description

PROCESS FOR PREPARING A METALLIZED SUBSTRATE, ANDTHE SUBSTRATE AND USES THEREOF

DESCRIPTION

TECHNICAL AREA

The invention belongs to the technical field of surface coatings.

More particularly, the present invention relates to a metallization process using substrates coated with organic films capable of developing interactions of the chelation or complexation type with metal ions. The present invention also relates to the products, intermediate or final, obtained during this metallization process and their use in various fields of application.

STATE OF THE PRIOR ART

Metallization, which consists of coating the surface of a part with a thin layer of metal, is used in many fields such as aeronautics, automobiles where certain accessories are coated with chromium, electronics, fittings, decoration including silver-plated dishes, cosmetics, tin-plated food containers, etc. There is therefore a great interest in the development of a metallization process.

The state of the art already knows different techniques for obtaining such a metallization. For example, electroplating using a solution containing the salt of the metal to be electrodeposited and in which the object to be metallized, which is conductive, is placed, is the technique generally implemented. In order to obtain a regular metallic coating having good grain quality and solidly and tightly bonded to the object to be metallized, the electrodeposition requires rigorously controlled conditions such as the current density and the temperature used, as well as a careful cleaning of the surface of the object.

The metallization of the surface of small objects such as particles or nanoparticles is useful in the medical field as well therapeutic as diagnostic. Indeed, in order to obtain extremely specific and localized images of the biological phenomenon studied, it is necessary to correlate at least two types of imaging. Currently, some imaging platforms coupling Magnetic Resonance Imaging (MRI) and fluorescence have shown their effectiveness in the study of tumor development in small animals. However, due to the attenuation of the fluorescence by the tissues, this type of system can not allow the visualization of a deep tumor on the man and thus to superimpose the two images.

The (nano) magnetic particles, ie comprising a magnetic metal or coated with such a metal, are widely used in various biomedical applications, especially as MRI contrast agents, but also for the vectorization of active ingredients, the treatment of anemia or the cancer diagnosis. Among them, the superparamagnetic iron oxides are used as contrast agents in MRI and for the treatment of cancer by hyperthermia because of their high degree of efficiency (relaxivity) and intrinsic bioabsorbability.

The development of ¹⁹ F detection methods by NMR with a very high magnetic field seems to open new perspectives. Indeed, fluoride is considered a trace trace element in the human body (bones and teeth). The detection of perfluorinated molecules thus makes it possible to have a very important signal / noise ratio (Srinivas et al., Magnetic Resonance in Medicine, 2007, 58, 725-734; Neubauer et al., Journal of Cardiovascular Magnetic Resonance, 2007, 9 , 565-573, Brix et al., Magnetic Resonance Imaging, 2005, 23, 967-976, Neubauer et al., Circulation, 2006, 114, 251-251).

Currently, there are few examples involving contrast agent / perfluorinated molecules. Only liposomes used in particular for the imaging of integrins use fluorine and gadolinium (Winter et al., Journal of Magnetism and Magnetic Materials, 2005, 293, 540-545, Morawski, et al., Magnetic Resonance in Medicine, 2004, 52). , 1255-1262, Morawski et al., Current Opinion in Biotechnology, 2005, 16, 89-92, Anderson et al., Magnetic Resonance in Medicine, 2000, 44, 433-439, Caruthers et al., Investigative Radiology, 2006 , 41, 305-312). These systems, however, suffer from an imposing size (> 150 nm) making their use for some applications unlikely. The design of nanoparticles incorporating metals, metal oxides or metal ions such as iron oxides and perfluorinated molecules would provide bimodal contrast agents ( ¹ H MRI at high contrast and ¹⁹ F), the correlation of the two. signals for obtaining more accurate images.

There is therefore a real need for a metallization process to obtain (nano) particles incorporating metals or metal oxides and perfluorinated molecules and, more generally, for a metallization process that is easy to implement and adaptable to all the surfaces encountered. in the aforementioned fields.

STATEMENT OF THE INVENTION

The present invention makes it possible to meet this expectation and the disadvantages of the state of the art. Indeed, it proposes a method that can be used for (nano) particles that are useful in therapy and in diagnostic imaging, but also for any type of surface, making it possible to obtain an object metallized on the surface and / or in its thickness, having a metallic coating. regular, with a good grain quality and firmly linked to said object. The invention also makes it possible to dispense with metallization catalysts such as platinum particles.

Thus, the present invention provides a method for preparing a metallized substrate comprising the steps of: a) grafting onto said substrate a polymer-type compound optionally having a group (or a structure) capable of chelating at least one metal ion; b) optionally subjecting said polymeric compound to conditions permitting its functionalization by a group (or a structure) capable of chelating at least one metal ion; c) providing said polymer-type compound capable of chelating at least one metal ion obtained after step (a) or (b) in contact with at least one metal ion; d) subjecting the polymer-type compound obtained in step (c) to conditions for reducing said chelated metal ion (s); e) optionally repeating steps (c) and (d) until a metallized substrate is obtained.

By "metallized substrate" is meant in the context of the present invention a substrate:

coated on the surface with a thin layer, typically from a few nanometers to several micrometers, of a metal and / or a metal oxide and / or comprising in its volume metals and / or metal oxides, dispersed and / or distributed in domain.

Among the metallized substrates, it is possible to distinguish substrates metallized only by a metal or only by an oxide metallized substrates metallized by the two types of metallic entities.

During step (a) of the process according to the invention, any technique allowing the grafting of a polymer-type compound onto a substrate is used, ie any technique allowing the formation of at least one covalent bond between a said substrate and an atom belonging to said polymer-type compound. The grafting technique can consist of:

- generating in the vicinity of a substrate ^ere the reactive entity such as entity resulting from an adhesion primer which is grafted onto the substrate and initiates the subsequent formation of the polymer compound, in particular by radical polymerization, and / or generate on the surface of the substrate a reactive entity such as a radical entity which initiates the subsequent formation of the polymer-type compound. As a result, the process according to the invention can be carried out with any type of substrate, inorganic or organic, having one or more atom (s) or group (s) of atoms that can be involved in a reaction. addition or radical substitution, such as CH, carbonyls (ketone, ester, acid, aldehyde), -OH, -SH, phosphates, ethers, amines or halogens, such as F, Cl, Br.

The substrate of inorganic nature can be in particular of a material chosen from conducting materials such as metals, noble metals, oxidized metals, transition metals, metal alloys and for example Ni, Zn, Au, Pt, Ti or steel.

The substrate may also be chosen from a material selected from semiconductor materials such as Si, SiC, AsGa or Ga. The term "semiconductor" means an organic or inorganic material having an electrical conductivity intermediate between the metals and the insulators. The conductivity properties of a semiconductor are influenced mainly by the charge carriers (electrons or holes) that the semiconductor exhibits. These properties are determined by two particular energy bands called the valence band (corresponding to the electrons involved in the covalent bonds) and the conduction band (corresponding to the electrons in an excited state and able to move in the semiconductor) . The gap represents the difference in energy between the valence band and the conduction band. A semiconductor also corresponds, unlike insulators or metals, to a material whose electrical conductivity can be controlled, to a large extent, by adding doping agents which correspond to foreign elements inserted into the semiconductor.

The substrate may also be chosen from a material chosen from photosensitive semiconductor materials, ie semiconductor materials whose conductivity may be modulated by variations in magnetic field, temperature or illumination, which affect the electron-hole pairs and charge carrier density. These properties are due to the existence of the gap as defined above. This gap generally does not exceed 3.5 eV for semiconductors, compared to 5 eV in materials considered insulators. It is therefore possible to populate the conduction band by excitation of the carriers through the gap, especially under illumination. The elements of group IV of the periodic table, such as carbon (in diamond form), silicon, germanium have such properties. Semiconductor materials can be formed from several elements, both Group IV, such as SiGe or SiC, Group III and V, such as GaAs, InP or GaN, or Group II and VI, such as CdTe or ZnSe .

Advantageously, in the context of the present invention, the photosensitive semiconductor substrate is of inorganic nature. Thus, the photosensitive semiconductor used in the context of the present invention is chosen from the group consisting of Group IV elements (more particularly, silicon and germanium); alloys of group IV elements (more particularly, SiGe and SiC alloys); alloys of group III and group V elements (referred to as "III-V" compounds, such as AsGa, InP, GaN) and alloys of group II and group VI elements (referred to as "II-VI" compounds , such as CdSe, CdTe, CU2S, ZnS or ZnSe). The preferred photosensitive semiconductor is silicon. Alternatively, it is possible that the photosensitive semiconductor is doped with one (or more) doping agent (s). The doping agent is chosen according to the semiconductor, and the doping is of the p or n type. The choice of the doping agent and the doping technologies are routine techniques for those skilled in the art. More particularly, the doping agent is selected from the group consisting of boron, nitrogen, phosphorus, nickel, sulfur, antimony, arsenic and mixtures thereof. By way of examples, for a silicon substrate, among the most widely used doping agents of the p type, there may be mentioned boron and, for the n-type dopants, arsenic, phosphorus and antimony. It is also possible to apply the process to substrates made of a non-conductive material such as non-conductive oxides such as SiO 2, Al 2 O 3 and MgO.

More generally, an inorganic substrate may consist, for example, of an amorphous material, such as a glass generally containing silicates or a ceramic, as well as a crystalline one such as diamond, which graphite may be more or less organized, like graphene, highly oriented graphite (HOPG), or carbon nanotubes.

As other substrates of organic nature, there may be mentioned in particular natural polymers such as latex or rubber, or artificial polymers such as polyamide and polyamide derivatives, polyethylene derivatives, and especially polymers having π-type bonds such as polymers bearing ethylenic bonds, carbonyl or imine groups. As particular examples of such polymers, mention may be made of acrylonitrile butadiene styrene (ABS) and

1 acrylonitrile butadiene styrene / polycarbonate

(ABS / PC). It is also possible to apply the process to more complex organic substrates such as leather, substrates comprising polysaccharides, such as cellulose for wood or paper, artificial or natural fibers, such as cotton or felt, and than to a polymer matrix or to polymers carrying basic groups such as tertiary or secondary amines and for example pyridines, such as poly-4 and poly-2-vinylpyridines (P4VP and P2VP) or more generally polymers containing aromatic and aromatic nitro groups. By "polymeric matrix" is meant in the context of the present invention a matrix of a polymer selected from polyurethanes, polyolefins, polycarbonates, polyethylene terephthalates, these polymers being advantageously fluorinated or perfluorinated. Advantageously, the polymeric matrix may be chosen from matrices of fluorinated polymers such as polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and tetrafluoropropylene (FEP), copolymers of ethylene and tetrafluoroethylene (ETFE), copolymers of hexafluoropropene and vinylidene fluoride (HFP-co-VDF), fluoride vinylidene and trifluoroethylene (VDF-co-TrFE) and vinylidene fluoride, trifluoroethylene and monochlorotrifluoroethylene (VDF-co-TrFE-co-chloro-TrFE). The size of the substrate used in the context of the present invention may be nanometric, micrometric, millimetric or metric. Indeed, the present invention applies to nanoparticles, microparticles, electronic elements, mirrors, decorative objects, optical data storage disks (compact discs), bodywork elements, etc.

Advantageously, the grafting of step (a) of the process according to the invention is a grafting chosen from the group consisting of chemical grafting, electrografting and radiochemical grafting.

By "chemical grafting" is meant, in the context of the present invention, a grafting using highly reactive (typically radical) molecular entities capable of forming covalent bond-type bonds with a surface of interest, said molecular entities being generated regardless of the surface on which they are intended to be grafted. Thus, the "radical grafting" is such a "chemical grafting".

More particularly, the grafting step (a) involving a chemical grafting comprises the steps of: a) contacting the substrate to be metallized with a solution Si comprising at least one adhesion primer and optionally at least one monomer other than the adhesion primer and radically polymerizable; bi) subjecting said Si solution to non-electrochemical conditions allowing the formation of radical entities from said adhesion primer.

By "adhesion primer" is meant, in the context of the present invention, any organic molecule capable, under certain non-electrochemical or electrochemical conditions, of forming either radicals or ions, and particularly cations, and thus to participate in chemical reactions. Such chemical reactions may in particular be chemisorption and in particular chemical grafting or electrografting. Thus, such an adhesion primer is capable, under non-electrochemical or electrochemical conditions, of chemisorbing on the surface of the substrate, in particular by radical reaction, and of presenting another reactive function with respect to another radical after this chemisorption. Thus, the radical reaction leads to the formation of covalent bonds between the surface and the grafted adhesion primer derivative and then between said grafted derivative and molecules present in its environment, such as radically polymerizable monomers or other dimer primers. accession.

The adhesion primer is advantageously a cleavable aryl salt selected from the group consisting of aryl diazonium salts, aryl salts and the like. ammonium salts, aryl phosphonium salts, aryl iodonium salts and aryl sulfonium salts. In these salts, the aryl group is an aryl group which may be represented by R as defined below. Among the cleavable aryl salts, mention may in particular be made of the compounds of formula (I) below:

RN ₂ ⁺ , A ^" (I) wherein: - A represents a monovalent anion and

- R represents an aryl group. As the aryl group of the cleavable aryl salts and in particular the compounds of formula (I) above, mention may advantageously be made of aromatic or heteroaromatic carbonaceous structures, optionally mono- or polysubstituted, consisting of one or more aromatic rings or heteroaromatic compounds each having from 3 to 8 atoms, the heteroatom (s) possibly being N, O, P or S. The substituent (s) may contain one or more heteroatoms, such as N, O, F, Cl, P, Si, Br or S, as well as C1-C6 alkyl groups or C4-C12 thioalkyl groups in particular.

Within the cleavable aryl salts and especially compounds of formula (I) above, R is preferably chosen from aryl groups substituted with electron-withdrawing groups such as -NO ₂ , ketones, -CN, -CO ₂ H, the esters and their salts. Within the compounds of formula (I) above, A may in particular be chosen from anions inorganic compounds such as halides such as I, Br and Cl ^" , haloborates such as tetrafluoroborate, perchlorates and sulphonates and organic anions, such as alcoholates and carboxylates, etc. As compounds of formula (I), it is particularly suitable for advantageously to use a compound selected from the group consisting of 4-nitrobenzenediazonium tetrafluoroborate, tridecylfluorooctylsulfamylbenzene diazonium tetrafluoroborate, phenyldiazonium tetrafluoroborate, 4-nitrophenyldiazonium tetrafluoroborate, 4-bromophenyldiazonium tetrafluoroborate, 4-aminophenyldiazonium chloride , 2-methyl-4-chlorophenyldiazonium chloride, 4-benzoylbenzenediazonium tetrafluoroborate, 4-cyanophenyldiazonium tetrafluoroborate, 4-carboxyphenyldiazonium tetrafluoroborate, 4-acetamidophenyldiazonium tetrafluoroborate, 4-phenylacetic acid diazonium tetrafluoroborate , the sulfate of 2 methyl-4 - [(2-methylphenyl) diazenyl] benzenediazonium chloride, 9,10-dioxo-9,10-dihydro-1-anthracenediazonium chloride, 4-nitronaphthalenediazonium tetrafluoroborate and naphthalenediazonium tetrafluoroborate. By "adhesion primer derivative" is meant, in the context of the present invention, a chemical unit resulting from the adhesion primer, after the latter has reacted with the surface, by chemical grafting, and optionally, by reaction. radical, with another molecule present in its environment such as an adhesion primer or a monomer radically polymerizable, said other molecule giving the second organic film pattern. Thus, the first organic film pattern is a derivative of the adhesion primer which has reacted with the surface and with another molecule present in its environment.

The radically polymerizable monomer (s) used in the context of the process of the invention correspond to the monomers capable of polymerizing under radical conditions after initiation by a radical chemical entity. Typically, these are molecules comprising at least one ethylenic type bond. In particular, the polymerizable monomer (s) is (are) chosen from the following monomers of formula (II):

in the group R 1 to R ₄ , which may be identical or different, represent a non-metallic monovalent atom such as a halogen atom, a hydrogen atom or a saturated or unsaturated chemical group, such as an alkyl or aryl group; a group -COOR ₅ or -OC (O) R ₅ in which R ₅ represents a hydrogen atom or a C 1 -C 12 alkyl group and preferably a C 1 -C 6 alkyl group, a nitrile, a carbonyl, an amine or a amide.

The radically polymerizable monomers are advantageously selected from the group consisting of vinyl esters such as vinyl acetate, acrylic acid, acrylonitrile, methacrylonitrile, methyl methacrylate, ethyl methacrylate, butyl methacrylate, propyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, glycidyl methacrylate, and derivatives thereof; acrylamides and especially methacrylamides of aminoethyl, propyl, butyl, pentyl and hexyl, cyanoacrylates, di-acrylates and di-methacrylates, tri-acrylates and tri-methacrylates, tetra-acrylates and tetra-methacrylates ( such as pentaerythritol tetra-methacrylate), styrene and its derivatives, parachlorostyrene, pentafluorostyrene, N-vinylpyrrolidone, 4-vinylpyridine, 2-vinylpyridine, vinyl halides, acryloyl or methacryloyl, di-vinylbenzene (DVB), and more generally vinyl or acrylate-based crosslinking agents, methacrylate, and their derivatives.

The solution Si may further comprise a solvent. The latter may be a protic solvent or an aprotic solvent. It is preferred that the adhesion primer which is employed be soluble in the solvent of the Si solution.

By "protic solvent" is meant, in the context of the present invention, a solvent which comprises at least one hydrogen atom capable of being released in the form of a proton.

The protic solvent is advantageously chosen from the group consisting of water, deionized water, distilled water, acidified or not, acetic acid, hydroxylated solvents such as methanol and ethanol, and low glycols. weight Molecules such as ethylene glycol, and mixtures thereof. In a first variant, the protic solvent used in the context of the present invention consists only of a protic solvent or a mixture of different protic solvents. In another variant, the protic solvent or the mixture of protic solvents may be used in admixture with at least one aprotic solvent, it being understood that the resulting mixture has the characteristics of a protic solvent.

By "aprotic solvent" is meant, in the context of the present invention, a solvent which is not considered as protic. Such solvents are not likely to release a proton or accept one under non-extreme conditions.

The aprotic solvent is advantageously chosen from dimethylformamide (DMF), acetone, tetrahydrofuran (THF), dichloromethane, acetonitrile, dimethyl sulfoxide (DMSO), ethyl acetate and mixtures thereof.

It is preferable that the adhesion primer be soluble in the solvent of the Si solution. Within the meaning of the invention, an adhesion primer is considered to be soluble in a given solvent if it remains soluble up to a concentration of 0.5 M, ie its solubility is at least 0.5 M under normal conditions of temperature and pressure (CNTP). Solubility is defined as the analytical composition of a saturated solution as a function of the proportion of a given solute in a given solvent; it can in particular express itself in molarity. A solvent containing a given concentration of a compound will be considered saturated, when the concentration will be equal to the solubility of the compound in that solvent. Solubility can be finite as infinite. In the latter case, the compound is soluble in any proportion in the solvent.

The amount of adhesion primer present in the solution Si used in accordance with the process according to the invention may vary according to the wishes of the experimenter. This amount is particularly related to the desired organic film thickness and the amount of adhesion primer that it is possible and possible to integrate the film. Thus to obtain a grafted film on the entire surface in contact with the solution, it is necessary to employ a minimum amount of adhesion primer that can be estimated by molecular size calculations. According to a particularly advantageous embodiment of the invention, the concentration of adhesion primer in the liquid solution is between 10 ^{~ 6} and 5 M approximately, preferably between 10 ^"3 and 10 ^{" 1} M.

When the solvent is a protic solvent, and advantageously, in the case where the adhesion primer is an aryl diazonium salt, the pH of the solution is typically less than 7. It is recommended to work at a pH of between 0.degree. and 3 when the preparation of the adhesion primer is carried out in the same medium as that of the grafting. If necessary, the pH of the solution can be adjusted to the desired value using one or more agents acidifiers well known to those skilled in the art, for example with the aid of inorganic or organic acids such as hydrochloric acid, sulfuric acid, etc.

The adhesion primer can either be introduced in the state in the solution Si as defined above, or be prepared in situ in the latter. Thus, in a particular embodiment, the process according to the present invention comprises a step for preparing the adhesion primer, especially when the latter is an aryl diazonium salt. Such compounds are generally prepared from arylamine, which can comprise several amino substituents, by reaction with NaNO 2 in an acid medium or by reaction with NOBF ₄ in an organic medium. For a detailed description of the experimental methods that can be used for such an in situ preparation, those skilled in the art can refer to the article by Bélanger et al., 2006 (Chem Mater 18, pages 4755-4763). Preferably, the grafting will then be carried out directly in the solution for preparing the aryl diazonium salt.

The radical polymerizable monomers may be soluble to a certain proportion in the solvent of the Si solution, ie the value of their solubility in this solvent is finite, in particular less than 0.1 M, and in particular between 5.10 ² and 10 ^{~ 6} M. The invention also applies to a mixture of two, three, four or more elements chosen from the elements previously described, the amount of these monomers in the solution Si may vary according to the desire of the experimenter. amount may be greater than the solubility of the element in question in the solvent of the Si solution used and may represent for example 18 to 40 times the solubility of said element in the solution at a given temperature, generally the ambient or reaction temperature. . Under these conditions, it is advantageous to employ means for dispersing the monomer molecules in the solution such as a surfactant or ultrasound. The solution Si comprising an adhesion primer and optionally at least one radically polymerizable monomer can additionally contain at least one surfactant and this, in particular to improve the solubility of said monomer (s). A precise description of the surfactants that can be used in the context of the invention is given in patent application FR 2 897 876 to which the person skilled in the art can refer. A single surfactant or a mixture of several surfactants can be used. By "non-electrochemical conditions" implemented in step (bi) of the process according to the invention is meant in the context of the present invention in the absence of electrical voltage. Thus, the non-electrochemical conditions used in step (bi) of the process according to the invention are conditions which allow the formation of radical entities from the adhesion primer, in the absence of the application. any electrical voltage to the surface on which the organic film is grafted. These conditions involve parameters such as, for example, the temperature, the nature of the solvent, the presence of a particular additive, stirring, pressure while the electric current does not occur during the formation of radical entities. The non-electrochemical conditions allowing the formation of radical entities are numerous and this type of reaction is known and studied in detail in the prior art (Rempp & Merrill, Polymer Synthesis, 1991, 65-86, Huthig & Wepf). It is thus possible for example to act on the thermal, kinetic, chemical, photochemical or radiochemical environment of the adhesion primer in order to destabilize it so that it forms a radical entity. It is of course possible to act simultaneously on several of these parameters.

In the context of the present invention, non-electrochemical conditions allowing the formation of radical entities are typically selected from the group consisting of thermal, kinetic, chemical, photochemical, radiochemical conditions and combinations thereof. Advantageously, the non-electrochemical conditions are chosen from the group consisting of thermal, chemical, photochemical and radiochemical conditions and their combinations with each other and / or with the kinetic conditions. The non-electrochemical conditions used in the context of the present invention are more particularly chemical conditions.

The thermal environment is a function of the temperature. Its control is easy with the means of heating usually employed by the man of the job. The use of a thermostated environment is of particular interest since it allows precise control of the reaction conditions.

The kinetic environment essentially corresponds to the agitation of the system and the friction forces. It is not a question here of the agitation of the molecules in itself (elongation of bonds, etc.), but of the global movement of the molecules. The application of a pressure makes it possible in particular to bring energy to the system so that the adhesion primer is destabilized and can form reactive species, especially radicals.

Finally, the action of various radiations such as electromagnetic radiation, γ radiation, UV rays, electron or ion beams may also sufficiently destabilize the adhesion primer to form radicals and / or ions. The wavelength used will be chosen according to the primary used. For example, a wavelength of about 306 nm will be used for 4-hexylbenzenediazonium.

In the context of the chemical conditions, one or more chemical initiator (s) is used in the reaction medium. The presence of chemical initiators is often coupled with non-chemical environmental conditions as discussed above. Typically, a chemical initiator will act on the adhesion primer and will generate the formation of radical entities from the latter. It is also possible to use chemical initiators whose action is not primarily related to environmental conditions and which can act on wide ranges of thermal or kinetic conditions. The initiator will preferably be adapted to the environment of the reaction, for example to the solvent. There are many chemical initiators.

There are generally three types depending on the environmental conditions used: thermal initiators, the most common of which are peroxides or azo compounds. Under the action of heat, these compounds dissociate into free radicals. In this case, the reaction is carried out at a minimum temperature corresponding to that required for formation of radicals from the initiator. This type of chemical initiator is generally used specifically in a certain temperature range, depending on their kinetics of decomposition; the photochemical or radiochemical initiators which are excited by radiation triggered by irradiation (most often by UV, but also by γ radiation or by electron beams) allow the production of radicals by more or less complex mechanisms. BusSnH and Σ2 belong to photochemical or radiochemical initiators; essentially chemical initiators, this type of initiators acting rapidly and under normal conditions of temperature and pressure on the adhesion primer to enable it to form radicals and / or ions. Such initiators generally have a redox potential which is lower than the reduction potential of the primary adhesion used in the reaction conditions.

Depending on the nature of the primer, it may thus be for example a reducing metal, such as iron, zinc, nickel; a metallocene such as ferrocene; an organic reducing agent such as hypophosphorous acid

(H3PO2) or ascorbic acid; of an organic or inorganic base in proportions sufficient to allow destabilization of the adhesion primer.

Advantageously, the reducing metal used as chemical initiator is in finely divided form, such as wool (also called more commonly "straw") metal or metal filings. Generally, when an organic or inorganic base is used as a chemical initiator, a pH of greater than or equal to 4 is generally sufficient. Radical reservoir-type structures, such as polymer matrices previously irradiated with an electron beam or with a heavy ion beam and / or with all the irradiation means mentioned above, can also be used as chemical initiators to destabilize the adhesion primer and lead in particular to the formation of radical entities from the latter.

It is useful to refer to the article by Mevellec et al., 2007 (Chem Mater, vol 19, pages 6323-6330) for the formation of active species.

In a second variant of step (a) of the method according to the invention, the grafting implemented is electrografting. By "electrografting" is meant, in the context of the present invention, a method of electro-initiated and localized grafting of an adhesion primer capable of being electrically activated, on a conductive or semiconductive surface of the electricity or a composite surface comprising conductive and / or semiconducting portions of electricity, by contacting said adhesion primers with said surface. In this method, the grafting is carried out electrochemically in a single step on the conductive or semiconductive surface of the electricity or on selected, defined areas of said conductive and / or semiconducting portions. Said surface (or zones) is (are) brought (s) to a potential greater than or equal to a threshold electric potential determined with respect to a reference electrode, said threshold electric potential being the potential beyond which the grafting occurs said adhesion primers. Once said grafted adhesion primers, the latter have another reactive function vis-à-vis another radical and able to engage a radical polymerization that does not depend on any electrical potential.

Advantageously, this second variant comprises the steps of: β2) contacting the conductive or semiconductor substrate with a solution S2 comprising at least one adhesion primer and optionally at least one polymerizable monomer different from said adhesion and polymerizable primer by radical way in particular as previously defined; b ₂ ) biasing said substrate to an electric potential that is more cathodic than the reduction potential of the adhesion primer implemented in step (a ₂ ), the order of steps (a ₂ ) and (b ₂ ) being arbitrary .

This variant applies to conductive or semiconductor substrates as previously defined. Thus, if the substrate used in the context of the present invention is a photosensitive semiconductor material as defined above, the method further comprises a step (c ₂ ) of exposing said substrate to light radiation whose energy is at least equal to that of the gap of said semiconductor. For more details on this particular implementation, reference should be made to the patent application published under the number FR 2 921 516.

Everything that has been described, in the context of chemical grafting, for the primary of adhesion, for the

(or the) radically polymerizable monomer (s), for the solution Si, namely the solvent, the amounts of adhesion primer and of polymerizable monomers, the preparation of the in situ adhesion primer and the possible The presence of a surfactant is also applicable to electrografting. It should be noted, however, that the solvent of the solution S2 is advantageously a protic solvent as defined above. According to the invention, it is preferable that the electrical potential employed in step (b ₂ ) of the process according to the present invention is close to the reduction potential of the adhesion primer implemented and which reacts on the surface. Thus the value of the electric potential applied can be up to 50% higher than the reduction potential of the adhesion primer, more typically it will not be greater than 30%.

This variant of the present invention can be implemented in an electrolysis cell comprising different electrodes: a first working electrode constituting the surface intended to receive the film, a counter electrode, and possibly a reference electrode.

The polarization of said surface may be carried out by any technique known to those skilled in the art and especially under linear or cyclic voltammetric conditions, under potentiostatic, potentiodynamic, intensiostatic, galvanostatic, galvanodynamic or by simple or pulsed chronoamperometry. Advantageously, the process according to the present invention is carried out under conditions of static or pulsed chronoamperometry. In static mode, the electrode is polarized for a duration generally less than 2 h, typically less than 1 h and for example less than 20 min. In pulsed mode, the number of pulses will be included, preferably between 1 and 1000 and, even more preferably, between 1 and 100, their duration generally being between 100 ms and 5 s, typically 1 s. By "radiochemical grafting" is meant in the context of the present invention a particularly radical reaction grafting involving a substrate, such as a polymeric matrix, previously irradiated. Thus, this variant applies mainly to organic substrates and, in particular, substrates of polymeric matrix type as defined above.

More particularly, the grafting step involving radiografting comprises the steps of: β3) irradiating a substrate of polymeric matrix type in particular as defined above; b3) bringing the irradiated substrate obtained in step (a) into contact with at least one adhesion primer and / or at least one radically polymerizable monomer.

The step (β ₃ ) of irradiation has the function of creating free radicals in the material constituting the matrix, this creation of free radicals being a consequence of the energy transfer during the irradiation of said material.

In a first variant of step (a), the latter may consist of subjecting the polymer matrix to an electron beam (variant called

"Electronic irradiation"). More particularly, this step may consist in sweeping the polymer matrix with an accelerated electron beam, in particular emitted by an electron accelerator (for example, a Van de Graaf accelerator, 2.5 MeV). In the case of electron beam irradiation, the Deposition of energy is homogeneous, which means that the free radicals created by this irradiation will be evenly distributed in the volume of the matrix. The irradiation dose generally varies from 10 to 500 kGy and in particular from 50 to 150 kGy.

In a second variant of step (β3), the latter may consist in subjecting the polymer matrix to bombardment by heavy ions and in particular by a heavy ion beam. By "heavy ions" is meant ions whose mass is greater than that of carbon. Generally, these are ions selected from krypton, lead and xenon.

From a mechanistic point of view, when the heavy energy vector ion passes through the matrix, its speed decreases. The ion gives up its energy, creating damaged areas, whose shape is approximately cylindrical. These areas called "latent traces" include two regions: the heart and the halo of the trace. The core of the trace is a totally degraded zone, namely an area where there is rupture of the constituent bonds of the material generating free radicals. This core is also the region where the heavy ion transmits a considerable amount of energy to the electrons of the material. Then, from this heart, there is emission of secondary electrons, which will cause defects far from the heart, thus generating a halo.

In the case of heavy ion irradiation, the energy deposition is distributed according to the irradiation angle and is inhomogeneous. It is possible to create traces arranged according to a diagram predetermined, and thereby induce consequently the grafting of units from the adhesion primers and / or radically polymerizable monomers only in the aforementioned traces which thus form "graft domains". Thus, it is possible to induce various grafting schemes, in particular by modulating the irradiation angle relative to the normal of the faces of the matrix. The irradiation dose generally ranges from 1 to 1000 kGy. In a third variant of step (β3), the latter may consist in subjecting the polymer matrix to (i) irradiation with heavy ions

(ii) followed by a chemical revelation, generally by hydrolysis, of latent traces created by the passage of heavy ions, after which open channels are obtained and then (iϋ) electron irradiation as defined above. said open channels, from which the radiografting can take place. The chemical revelation consists in bringing the matrix into contact with a reagent able to hydrolyze the latent traces having short chains of polymers formed by splitting existing chains during the passage of a heavy ion in the material during the irradiation (i), so as to form hollow channels in place of them, the rate of hydrolysis during the revelation being greater than that of non-irradiated parts. The reagents capable of revealing latent traces that can be selective are a function of the material constituting the matrix. It is possible to use, for fluorinated polymeric matrices such as previously described, a strongly basic and oxidizing solution, such as a KOH ION solution in the presence of KMnO ₄ at 0.25% by weight at a temperature of 65 ^° C. and, for polymers such as polyethyleneterephthalate or polycarbonate, a basic solution, optionally coupled with a trace sensitization by UV. The treatment leads to the formation of hollow cylindrical pores whose diameter is adjustable as a function of the attack time with the basic and oxidizing solution. Generally heavy ion irradiation will be carried out so that the membrane has a number of traces per cm ² between 10 ⁶ and 10 ¹¹ , especially between 5.10 ⁷ and 5.10 ¹⁰ , more especially to 10 ¹⁰ . Other information concerning the reagents and the operating conditions that can be used for the chemical revelation as a function of the material constituting the matrix can be found in Rev. Mod. Phys., 1983, 55, p-925.

After this step of revelation, the electron irradiation (iii) is carried out to induce the formation of free radicals on the wall of the channels, the implementation being in this case similar to that which has been exposed for the electronic irradiation in general and allows the formation of a polymeric coating to fill the pores. Generally the beam is oriented in a direction normal to the surface of the membrane and the surface thereof is scanned homogeneously. The irradiation dose generally varies from 10 to 200 kGy for subsequent radiografting, it will typically be close to 100 kGy for PVDF. The dose is generally as it is greater than the gel dose, which corresponds to the dose from which the recombinations between radicals are favored resulting in the creation of interchain bonds leading to the formation of a three-dimensional network (or else crosslinking) it is that is to say the formation of a gel, in order to induce at the same time crosslinking thus making it possible to improve the mechanical properties of the final polymer. Thus, for PVDF, it is recommended that the dose be at least 30 kGy.

In a fourth variant of step (a), the latter may consist in subjecting the polymer matrix to UV radiation. In this variant, the UV radiation as a function of its intensity and its duration can cause the formation of free radicals uniformly distributed in the volume of the matrix or only at the surface. In addition, as shown in paragraph Ilg of the experimental part, UV irradiation can cause activation of the defects and impurities of the polymeric matrix prior to the creation of free radicals. Advantageously, the UV radiation can be generated by any UV lamp such as an excimer lamp emitting incoherent radiation in the UV-V, in particular at 172 nm (surface modification and in the volume of the polymer matrix) or a lamp UV emitting at 320-500 nm (surface modification of the polymeric matrix). Irradiation can be continuous or sequential. The duration of a continuous irradiation generally varies from 5 minutes to 1 hour and in particular from 15 to 45 minutes. In the case of sequential irradiation, the polymeric matrix may be subjected to more than two irradiations, duration and intensity, identical or different. The duration of these irradiations generally varies from 5 to 30 min and in particular from 10 to 20 min. As mentioned above, the irradiation step (β3) of the polymer matrix makes it possible to create free radicals generally via the prior creation of non-radical reactive species resulting from the activation of the defects and impurities in the matrix material.

The radicals and reactive species, present in such an irradiated matrix and obtained after any of the variants of step (a), may be trapped in polymer crystals, which correspond to crystalline domains within a polymer material and are generally called crystallites, in order to prolong the life of the matrix in irradiated form. It is therefore recommended to use matrices containing crystallites and preferably between 30% and 50%, usually 40%. Thus, such irradiated matrices can be used immediately or stored under an inert atmosphere, such as nitrogen, and generally cold (-18 ⁰ C), for several months before their use and in particular the implementation of the step ( b ₃ ).

During step (b3), the adhesion primer and the radically polymerizable monomer are as previously defined and are in particular in the form of a compound of formula (I) or (II) as defined above. . This primer or this monomer is capable of reacting with a free radical for on the one hand, forming a covalent bond with the matrix and, on the other hand, initiating a radical polymerization reaction involving other primers and / or other radically polymerizable monomers. Advantageously, the (or mixture) of primer (s) and / or the (or mixture) of monomer (s) used in step (b3) is (are) in a solution S3 in the presence of a protic or non-protic solvent as previously defined. As protic solvent and non-protic solvent used in step (b3), mention may be made respectively of water and ethyl acetate.

The amounts of adhesion primer (s) and / or monomer (s) present in the solution S3 are identical to the amounts of these elements in the solutions Si and S2 as previously defined. The presence of surfactants as defined above is also possible. By way of example, when the solution S3 contains only one (or a mixture of) monomer (s), its (their) amount is between 10 and 90% by weight in the solution S3. The solution S3 may also contain a compound limiting the homopolymerization of the monomers used, such as Mohr's salt, in amounts of between 0.01 and 1% by weight and in particular between 0.05 and 0.5% by weight. mass .

At the end of steps (bi), (b2) and (b3) and therefore at the end of step (a) according to the invention, the substrate has at least one polymer-type compound grafted onto its surface and / or in its volume. The polymer-type compound used in the context of the present invention can be prepared from:

(i ') of a (or a mixture of) adhesion primer (s) as previously defined (chemical grafting, electrografting or radiografting);

(ii ') of a (or a mixture of) adhesion primer (s) as previously defined (s) in admixture with a (or a mixture of) polymerizable monomer (s) by radical way such as previously defined (chemical grafting, electrografting or radiografting);

(iii ') a (or a mixture of) radically polymerizable monomer (s) as previously defined (radiografting).

Thus, the compound obtained after the grafting step is polymer or copolymer, when the grafting is of the radiografting type and that this compound is derived from several monomeric units of the same or different chemical species that are the monomer (s) ( s) radically polymerizable using this grafting.

The compound obtained can also be "essentially" polymer or copolymer, resulting from several identical or different radical polymerizable monomeric units and / or adhesion primer molecules (case (ii ') above). The compounds obtained are "essentially" of the polymer type insofar as the film also incorporates species derived from the adhesion primer and not only monomers present. The compound obtained following the grafting step has a sequence in monomeric units (or units) in which the first unit (or first unit) is constituted by a derivative of the adhesion primer or derived from an adhesion primer, the other units (or units) being indifferently derived from or derived from adhesion primers and / or polymerizable monomers. In addition, it should be noted that, in the case (i ') above, the adhesion primer molecules can be qualified as polymerizable insofar as, by radical reaction, they can lead to the formation of molecules of relatively high molecular weight whose structure is formed essentially of units with multiple repetitions derived, factually or conceptually, from adhesion primer molecules. In the case where the step of chemical grafting, electrografting or radiografting is carried out only in the presence of identical or different adhesion primer molecules, the compound obtained after this step may consist solely of derived units. or from identical or different adhesion primers. For these reasons, the compound obtained after any of the variants of step (a) is a polymer-type compound.

The average length of the polymer-type compound (s) is easily controllable, whatever the variant of the grafting process of the present invention used. For each of parameters such as the duration of the step (bi), (b2) or (b3) and depending on the reagents it will use, the skilled person will be able to determine by iteration the optimal conditions to obtain a compound of given length. Since several polymer-type compounds can be grafted onto the substrate (potentially on each free radical created on the substrate (radiografting or electrografting) or grafted onto the substrate (chemical grafting)), the polymer-type compounds obtained following the step ( a) can be in the form of an organic film.

Advantageously, the process according to the present invention comprises an additional step, prior to grafting (chemical, electrochemical or radiografting), of cleaning the surface on which it is desired to graft the organic film, in particular by sanding, polishing, oxidative treatment and / or treatment. abrasive. Additional ultrasonic treatment with an organic solvent such as ethanol, acetone or dimethylformamide (DMF) is even recommended. It is preferable that the chosen solvent does not alter the substrate.

Thus, according to a particular embodiment, the substrate undergoes an oxidative pretreatment before step (a). This modality is particularly applicable to substrates of organic nature and more specifically to polymers. Such treatments are described in particular in Garbassi, F. Morra, M. Occhiello, E. Polymer Surfaces From Physics to Technology. 1995. John Wiley & Sons Ltd, England. The application of pretreatment allows oxidation of the surface and / or its abrasion.

Physical oxidative treatments can be distinguished from chemical oxidative treatments. Among the physical treatments, there may be mentioned in particular: "flame treatment" or "flaming": exposure to a flame, the treatment with the corona effect: exposure to the ionized medium surrounding an electrical conductor brought to a particular electrical potential n ' not causing the formation of an electric arc,

plasma treatment: exposure to a plasma, generally a cold plasma for which the ionization rate of the reactive species contained in the plasma is less than 10 ^-4 (generally less than

5000 K), UV treatment: exposure to UV radiation in the presence of oxygen or ozone, - X-ray or Y-ray treatment: exposure to high energy photons in the presence of oxygen,

electron or heavy ion irradiation treatment: exposure to a beam of electrons or heavy ions in the presence of oxygen (Zenkiewicz, M. et al., Applied Surface Science, 2007. 253, 8992-8999).

Among the chemical treatments, mention may be made in particular of: the Fenton type chemical reaction: corresponding to an oxidation in the presence of metal ions and of hydrogen peroxide, - oxidation by alcoholic potash,

the treatment with chemical oxidants such as, and not limited to, KMnO ₄ ZH ₂ SO ₄ , K ₂ Cr ₂ O ₇ ZH ₂ SO ₄ , KClO ₃ ZH ₂ SO ₄ , CrO ₃ ZH ₂ SO ₄ . - ozone treatment: exposure to an ozone flux, electrochemical treatments: exposure to an electrolytic bath in the presence of an electrical voltage (Brewis, DM, Dahm, RH International Journal of Adhesion & Adhesives, 2001. 21 , 397-409).

The oxidative treatment makes it possible in particular to improve the quality of the grafting as well as the reduction of the reaction time during this step

Advantageously, the compound of the graft polymer type following step (a) of the process according to the invention is, by nature, capable of chelating

(complexing) at least one metal ion. Indeed, thanks to the (x) monomer (s) polymerizable (s) radical and Zou or (x) primary (s) of adhesion from which it is derived, the organic film has at least one group or a structure capable of chelating (complexing) at least one metal ion. In this variant, step (b) of the method is optional.

A group (or structure) capable of chelating (complexing) at least one metal ion is a molecular structure advantageously neutral allowing the complexation of the cations, ie a structure having free doublets, thus containing non-quaternized nitrogen atoms, atoms sulfur or oxygen atoms. Advantageously, a group

(or a structure) capable of chelating (complexing) at least one metal ion is chosen from the group consisting of a group of amines, amides, ethers, carbonyls, carboxyls, carboxylates, phosphines, phosphine oxides, thioethers, disulphides, ureas, crown-ether, aza-crowns, thio-crowns, cryptands, sepulcrands ("sepulcrates"), podands, porphyrins as tetrakis (bezoic acid) - 4, 4 ', 4' ', 4' '' - (porphyrin-5, 10, 15, 20-tetrayl), calixarenes such as calix [4] arene, pyridines, bipyridines , terpyridines, quinolines, orthophenantroline compounds, naphthols, iso-naphthols, thioureas, siderophores, antibiotics, ethylene glycol, cyclodextrins (CD) such as natural cyclodextrins and peranhydrocyclodextrin derivatives , as well as substituted molecular structures and / or functionalized from these functional groups, and / or one or more complexing cavity (s) of the redox lock type. For more details on such groupings

(or structures), a person skilled in the art will be able to consult the patent applications FR 2 813 208 and FR 2 851 181.

Thus, the adhesion primers and radically polymerizable monomers that can be used in this variant have at least one of R 1, R 1, R ₂ , R 3 and R ₄ as defined above which is a suitable group (or structure) chelating (complexing) at least one ion as listed above or which is substituted by such a group. By way of examples, mention may be made of acrylic acid; 4-carboxyphenyldiazonium tetrafluoroborate; methyl methacrylate in which the methyl group of the ester has been replaced by a crown ether; 4-vinyl pyridine and methacrylamides of aminoethyl, propyl, butyl, pentyl and hexyl.

As a variant, the polymer-type compound grafted following step (a) of the process according to the invention is not capable of chelating (complexing) at least one metal ion. Thus, this polymer-type compound must be subjected to conditions enabling it to be functionalized by a group or a structure capable of chelating at least one metal ion and step (b) of the process according to the invention is mandatory.

Thus, if the adhesion primer (s) and / or the radically polymerizable monomer (s) have a precursor (s) of groups or structures capable of chelating metal ions, step (b) consists in modifying the precursor (s) contained in the polymer-type compound by one or more chemical reactions (s) ) simple. By way of example, for a polymer-type compound of which at least one unit is derived from 4-nitrophenyldiazonium tetrafluoroborate, the nitro function can be reduced by iron to give a polymer-type compound having an amine as a group capable of chelating. metal ions. Similarly, a polyacrylonitrile polymer comprising a nitrile group allows, after treatment with LiAlH ₄ , to access a compound having an amine as a group capable of chelating metal ions. Usefully the skilled person can refer to the international application WO 2004/005410.

Similarly, this functionalization may involve other chemical reactions such as nucleophilic additions and substitutions, electrophilic additions and substitutions, cycloadditions, rearrangements, transpositions and metatheses, as well as, more generally, click-chemistry reactions (Sharples et al. , Angew Chem Int Ed, 2001, 40, 2004-2021). Such reactions can be implemented to functionalize the polymer-type compound obtained in step (a) with a structure comprising a cyclodextrin, a calixarene or a porphyrin, said structure also comprising another group capable of reacting with a group of the polymer type compound. Functionalization of the polymer-type compound may involve groups on the surface of this compound, but also slightly less accessible groups, especially when this compound has been radiografted on a polymer matrix irradiated with heavy ions and therefore having latent traces. Step (b) may implement a solution and a swelling solvent. A swelling solvent corresponds to a solvent capable of penetrating into the polymer-type compound. Such solvents when contacted with the polymeric compound generally cause the swelling of this composed perceptibly by optical means, by eye, or by simple optical microscopy. A standard test for determining whether a solvent is particularly suitable for a polymer-type compound is to deposit a drop of solvent on the surface of the compound and observe whether the drop is absorbed within the compound. It is desirable to use from among a set of solvents tested those for which the absorption is the fastest. The use of such a solvent leads to deeper functionalization within the polymer-type compound. Of course, it is also preferable that the reagents used to make the reaction be soluble in such a solvent.

Step (c) of the process according to the present invention consists of putting the polymer-type compound capable of chelating (or complexing) the metal ions in the presence of such metal ions. This step (c) is therefore a chelation step (or complexation). For the purposes of the present invention, the term "metal ion" means an ion of the type M ^{n +} , with M representing a metal and n being an integer between 1 and 7, and generally between 1 and 4. Typically it is is an alkali metal ion, an alkaline earth metal, a lean metal (especially Al, Ga, In, Sn, Pb, Tl, Bi) or a transition metal. The present invention relates more particularly to the ions of a transition metal. Advantageously, a metal ion according to the invention is chosen from the group consisting of Ag ⁺ , Ag ²⁺ , Ag ³⁺ , Au ⁺ , Au ³⁺ , Cd ²⁺ , Co ²⁺ , Cr ²⁺ , Cu ⁺ , Cu ²⁺ , Fe ²⁺ , Hg ²⁺ , Mn ²⁺ , Ni ²⁺ , Pd ⁺ , Pt ⁺ , Ti ⁴⁺ and Zn ²⁺ . In step (c) of the process according to the invention, the metal ion is in a salt solution S ₄ , advantageously in an aqueous saline solution, in the presence of an anionic counterion. As usable anionic counterions, mention may be made of a chloride (Cl ^" ) a bromide (Br ^" ), a fluoride (F ^" ), an iodide (I ^" ), a sulphate (SO ₄ ^{2 "} ), a nitrate (NO ₃ ^" ) or phosphate (PO ₄ ^3" ).

It may be necessary to control the pH of the saline solution used in step (c), in particular so that the groups (or structures) capable of chelating the metal ions carried by the polymer-type compound are in a form suitable for this purpose. chelation, for example, in ionized form. Those skilled in the art will know according to the chelating groups carried by the polymer-type compound and the solution S ₄ , if it is necessary or not to modify the pH of this solution. If so, those skilled in the art know different acid / base pairs capable of modifying the pH such as CH 3 COOH / NH 3 or CH ₃ COOH / NaOH.

Finally, step (c) of chelation can be carried out with stirring, in particular by using a stirrer, a magnetic bar, an ultrasonic bath or a homogenizer and at a temperature below 60 ^° C., in particular between 5 and 50 ^° C. and, in particular, between 10 and 40 ^° C. The step (c) according to the invention is carried out, in a more specific embodiment, at ambient temperature. By "ambient temperature" is meant a temperature of 20 ° C ± 5 ° C. According to a particular modality, steps (a), (b) and (c) are performed simultaneously. Under these conditions, the solutions that can be used correspond to one and the same reactive solution So which contains the species necessary for carrying out the steps considered.

Step (d) of the process according to the invention consists in reducing the chelated (or complexed) metal ions by the polymer-type compound. Any reduction technique known to those skilled in the art can be used during this step. Advantageously, this reduction step is a chemical reduction, a photoreduction or an electrochemical reduction, especially when the substrate is conductive.

When step (d) according to the invention is a chemical reduction step, the latter implements a reducing solution S ₅ . Advantageously, the reducing solution S ₅ is basic. The reducing solution S ₅ comprises a reducing agent, in particular chosen from the group consisting of sodium borohydride (NaBH ₄ ), dimethylamine borane (DMAB-H (CH ₂ ) ₂ NBH ₃ and hydrazine (N ₂ H ₄ ). the reducing agent is NaBH ₄ , the pH of the reducing solution S ₅ is neutral or basic, whereas for DMAB the pH of the solution S ₅ is basic The reducing agent is present in the reducing solution S ₅ at a concentration of between 10 ^-4 and 5 M, in particular between 0.01 and 1 M and in particular of the order of 0.1 M (ie 0.1 M ± 0.01 M). chemical reduction can be performed at a temperature omitted between 30 and 90 ^° C., in particular between 40 and 80 ^° C. and in particular between 50 and 80 ^° C. In addition, the step (d) chemical reduction can last between 30 sec and 1 h, in particular between 1 and 30 min and in particular between 2 and 20 min.

When the step (d) according to the invention is an electrochemical reduction step, the latter can implement an electrochemical cell in which the substrate obtained following step (c) (ie substrate on which is grafted a compound of metal ion chelating polymer type) serves as a measuring electrode in the presence of a reference electrode such as a saturated KCl calomel electrode and a counter electrode such as a graphite counter electrode.

In this electrochemical cell, the electrodes are placed in a solution Se comprising a polar solvent, at least one metal ion and at least one counter-ion as previously defined. The amount (ions + counterions) can vary from 0.1 to 100 g / l, especially between 0.5 and 50 g / l and, in particular, between 1 and 20 g / l of solution Se. From the ions and counter-ions present in the solution Se of the initial potential of the latter, one skilled in the art will be able to iteratively determine the optimum conditions for the reduction step (c) such as the duration and the profile of the voltammetry cycle and the voltage imposed during this cycle.

Step (d) according to the invention may be a photoreduction step. Typically Ag ⁺ , Pt ⁺ , Pd ⁺ , and Au ⁺ ions can be reduced by UV irradiation (Redjala T & al., New Journal of Chemistry, Vol 32, Issue 8, 2008. Eda Ozkaraoglu, Ilknur Tune and Sefik Suzer, Polymer, Vol.50, Issue 2, 2009). Generally, this reduction involves an intermediate which can typically be a counter-ion or an organic molecule which, subjected to UV irradiation, provides the electrons necessary for the reduction of metal ions. In addition, this type of method may involve linear optical phenomena and nonlinear optics (typically a multiphoton process). The use of laser can provide nano- or microstructuring of the metal deposit (Tanaka T, Ishikawa A, Kawata S, Applied Physics Letters, Vol 88, Issue 8, 2006. Kaneko K, Sun HB, Duan XM, Kawata S, Applied Physics Letters, Vol 83, Issue 7, 2003). This photoreduction is advantageously carried out in a solution S ₇ . The different characteristics and properties of the solution Se as previously defined also apply to the solution S ₇ .

The chemical reduction of the chelated metal ions on or in the graft polymer compound on the substrate or the electrochemical deposition of a metal on the measuring electrode, ie on or in the graft polymer compound on the substrate, is easily verifiable, typically, visually and in particular with the naked eye.

It should be noted that the implementation of a single step (c) and a single step (d) may not be sufficient to achieve the desired metallization. In this case, at least one new cycle with a new step (c) and a new step (d) must be performed. It is conceivable to carry out, after the ^1st chelation / reduction cycle, from 1 to 20 additional cycles, in particular from 1 to 15 additional cycles and, in particular from 1 to 10 additional cycles. By "additional cycle" is meant a step (c) followed by a step (d). From one cycle to another, conditions can:

- Be the same (same conditions during the chelation step and in particular same S ₅ chelation solution or S ₅ chelation solution of the same composition, same type and reduction conditions, same reduction solution Se or Se reduction solution Se same composition); slightly differing (conditions during the close chelation step and in particular solution S ₅ for chelating the composition close to and / or same type of reduction with close conditions and in particular a solution Se of reduction of close composition); - be different with in particular a change of type of reduction. By way of examples, it is possible to envisage a first cycle with a chemical reduction followed by a second cycle with an electrochemical reduction such as those previously defined.

It should also be pointed out that, despite several cycles of chelation / reduction, it is possible that there is no formation of a metal but only of a smaller form than that of the metal ion, namely an oxide. metallic. This variant is a function of the metal considered, conditions during reduction steps and the environment including the presence of oxygen. A suitable choice of conditions (redox potential of the reducing agent in the context of chemical reduction, for example) makes it possible to obtain the desired type of metallic entity. By modulating the experimental conditions, it is thus possible to obtain metallized substrates comprising different metallic entities: metal or metal oxide and also metal ions.

According to one embodiment of the invention, the method is applied to only a portion of the substrate, it is thus possible to prepare a metallized substrate selectively. For this, it is possible to selectively expose only one (or more) determined surface (s) of the substrate at certain stages of the process or to hide one or more surfaces that do not have to (f) not be treated according to the process. A mask, or buffer, typically corresponds to a physical entity that is neither grafted to the surface that is not to be treated, nor covalently bound thereto. It may especially be a solid material or a thin layer of material, typically from a few Angstroms to a few microns, generally of organic nature, deposited on the surface.

The mask makes it possible to locally "mask" the chemical reactivity of the substrate, the areas of the surface of the substrate equipped with the mask being preserved from the reaction environment (for example chemical or radiochemical). After removing the mask, the surface that was protected, unlike the one that was not equipped with a mask, will not react. The mask may for example consist of a thin layer of inorganic or organic material acting as a less cohesive layer easily removable under mild conditions. A layer of material is considered as such in that it does not require the use of extreme conditions harmful to the metallized substrate to be removed. Typically the mild conditions correspond to a simple chemical washing, generally carried out using a solvent in which the mask is soluble, to an ultrasonic treatment in a solvent in which the mask is soluble or to a rise in temperature. It is of course desirable that the mask is not soluble in the solvent employed in the step under consideration. Thus it is recommended to use a mask which has a surface affinity greater than that which it has for the reaction solvent.

The material constituting the mask can thus be chosen from a wide range. It will generally be chosen according to the nature of the substrate.

The mask can react with the entities generated during the process. In any case, it is possible to eliminate it to discover the areas of the surface of the protected substrate (comparable to so-called "lift-off" methods in lithography). Mask deposition techniques are well known to those skilled in the art. This may include coating, spraying or immersion. Thus, the mask, in the form of a thin layer of material, may for example be deposited by direct drawing from a felt (pencil type) impregnated with the selected material. On glass, it is, for example, possible to use, as a mask, a marker such as those proposed in stationery or fat. It is also possible to use the so-called "buffer" method. This technique is applicable especially in the case of substrates having a complexing surface for sulfur atoms, such as a gold surface, in which case the mask will generally be composed of alkylthiols, in particular long-chain alkylthiols, often C15-C20 and typically C18 (technique called "microimpression" or "microcontact printing" in English). More generally, conventional lithography techniques can be used to form the mask: spin-coating, then insolation through a physical mask or via a beam of light or controllable particles, then revelation.

The present invention also relates to the substrate that can be obtained following step (a) or step (b) of the process of the invention as defined above, said substrate being grafted with at least one compound of the type polymer capable of chelating at least one metal ion, hereinafter referred to as "substrate A". All variants in terms of substrate, compound of polymer type, grafting type apply to the substrate A according to the invention.

Substrate A can advantageously be used for complexing at least one metal ion and in particular for purifying a solution likely to contain at least one metal ion. Thus, the present invention relates to a method for purifying a solution capable of containing at least one metal ion consisting of putting said substrate A in contact with said solution and then subjecting said substrate to at least one reduction step as defined above ( step (d) previously defined). The solution that can be used for this purification process may be any solution likely to contain one (or more) metal ion (s). Advantageously, said solution is selected from the group consisting of any sample of wastewater, city water, river, sea, lake and underground. A substrate that is particularly suitable for this use is a substrate, in particular with a surface area of 1 cm ² to 10 m ² , in a polymeric matrix as defined above, in particular irradiated with an electron beam and which therefore has compounds of the type polymer grafted throughout its volume. In addition, the purification process may comprise an additional step, following the reduction, of recovery of the metals or metal oxides.

The present invention also relates to the substrate that can be obtained following step (c) of the process of the invention as previously defined, said substrate being grafted with at least one polymer-type compound chelating at least one metal ion, hereinafter referred to as "substrate B". All variants in terms of substrate, polymer type compound, graft type and metal ion apply to the substrate B according to the invention.

The substrate B may advantageously be used for its particular properties such as antifungal or antibacterial. Indeed, a substrate B on which Cu ²⁺ or Fe ²⁺ ions are chelated can for example be used as antifungal agent, a substrate B on which ions are chelated, in particular those specified in the application International patent WO 2001/05233, and particularly silver ions, such as Ag ⁺ , Ag ²⁺ or Ag ³⁺ , can be used as an antibacterial and / or antifungal. By way of example of substrate B that can be used for these applications, substrates coated with an organic film consisting of several polymer-type compounds, particularly useful in the medical field, such as a tissue, an implant, a surgical device, may be mentioned. a container for food or pharmaceutical products.

The present invention finally relates to the substrate that can be obtained by the method of the invention as defined above, hereinafter referred to as "substrate C".

Substrate C may be in the form of a substrate as previously defined (ie inorganic or organic, conductive, semiconductor or insulator), coated (ie grafted) with an organic metal or metal oxide film. Examples of such a substrate C include a valve element, an automobile accessory, dishes, a container for food products, cosmetic or therapeutic, (micro) particles used in cosmetics, etc. ....

Alternatively, the substrate C may have, on its surface and / or in its volume, several grafted polymer compounds, metal or metal oxide, dispersed or grouped in nanodomain (s). This variant is particularly applicable to substrates obtained by implementing a method according to the invention using a polymeric matrix and radiografting as previously defined.

Indeed, Figure 1 proposes different particles such as micro- or nanoparticles, which can be obtained by combining the method of the invention with a polymeric matrix and radiografting.

FIG. 1A corresponds to the case of a particle in the form of a polymeric matrix of PVDF type, subjected to UV irradiation having caused a modification of the matrix and therefore the grafting of PAA only on the surface, metals and metal oxides. thus finding on the surface of this particle. The particle of FIG. 1A is an example of an organic core particle (1), a metal shell (2).

FIGS. 1B and 1C correspond to the case of a particle in the form of a polymeric matrix of PVDF type, subjected to irradiation with electrons or optionally irradiation with UV as previously defined, resulting in a modification of the matrix and thus the grafting PAA on the surface and throughout the volume of the particle, metals and metal oxides are on the surface and throughout the volume of this particle. Figure IC and Figure ID differ from each other in that the metals and metal oxides are dispersed within the matrix (Figure 1B), whereas the particle of Figure 1C is completely metallized. The particle of FIG. 1B is metallized by two metallic entities: a core metal oxide (3) and a surface metal (4), it can be obtained by modulating the reaction conditions of steps c), d) and e) of process.

In the case of Figures IB and IC, there is a modulation of the conductivity in thickness of the metallized membrane.

Depending on the type of metal ion used in the process according to the invention, the substrate C obtained can be magnetic and used for this property. By way of example, there may be mentioned a substrate C which is a valve membrane, metallized, magnetic and used with an electromagnet in a valve opening / closing system.

Similarly, a substrate B or a substrate C according to the invention in the form of magnetic micro- or nanoparticles according to the invention can be useful in imaging and in particular for detecting ions by paramagnetic resonance (RPE). In addition, the PVDF which constitutes the polymeric matrix of these particles has the advantage of being a fluoropolymer thus having a large number of fluorine. Since the ¹⁹ F signal is proportional to the amount of fluorine present in the molecule of interest, it appears to be a prime candidate for ¹⁹ F imaging. Moreover, because of its structure and method of polymerization, the ¹⁹ F signal of the PVDF has a relatively fine intense signal. By combining the induced effect on the relaxation of water by the metals or metal oxides or metal ions or the different combinations of the various elements previously described present, either on the surface of the system, or as a whole and the signal of the fluorine base polymer, one obtains a bimodal system H / F potential for MRI imaging. The substrate C according to the invention can also be used to constitute the triple point for fuel cells (or PEMFC for "Proton Exchange Membrane Fuel Cells"). The triple point or triple point zone is a zone in an alkaline fuel cell allowing both electronic conduction, ionic conduction and catalytic reaction. In this application, the substrate C is advantageously in the form of a flexible membrane metallized for example with platinum. Finally, the substrate C that can be obtained by the process according to the invention may have a biological or biologically active molecule immobilized on its surface. By "biological or biologically active molecule" is meant in the context of the present invention a molecule selected from the group consisting of amino acids; peptides; the proteins such as gelatin, protein A, protein G, streptavidin, biotin, an enzyme such as glucose oxidase; antibodies and antibody fragments; cell or membrane receptors; polysaccharides such as glycoaminoglycans and especially heparin; lipids ; cells or cell parts such as organelles or cell membranes and nucleic acids such as DNA and RNA. The present invention therefore relates to a biochip comprising a substrate C according to the invention on which is immobilized at least one biological or biologically active molecule as defined above.

Those skilled in the art know various techniques for immobilizing on a substrate C according to the invention at least one biological or biologically active molecule by functionalizing the latter with or without the involvement of coupling agents. As a variant, the substrate C can have at least one biological or biologically active molecule immobilized on its surface and without functionalization. The substrate C can thus be used as a magnetic addressing chip or magneto-chip. Whatever the variant, a substrate C on which is immobilized, with or without functionalization, a biological or biologically active molecule as defined above, and preferably metallized according to a determined map, can be used as a biochip or for to follow a biological phenomenon of the redox type or involving an electron transfer.

As an example of a particular application, the substrate C according to the invention can immobilize biological or non-biological catalysts to dissociate the hydrogen, the metal layer of said substrate C making it possible to recover the electrons.

Other features and advantages of the present invention will become apparent to those skilled in the art on reading the examples below given for illustrative and non-limiting, with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematizes various metallized substrates that can be obtained by the process according to the invention.

Figure 2 shows the IR spectrum of a nickel metallized membrane following the ^1st chelation bath, following the 2 ^nd chelation bath and following the

2 ^nd reduction, a blank membrane is used as a control.

Figure 3 shows the spectrum of the Ni2p layer of a nickel metallized membrane. Figure 4 shows the IR spectrum of a metallized membrane by Copper following the 3 ^rd reduction, a blank membrane as a control.

Figure 5 shows the spectrum of the Cu2p layer of a metallized membrane with copper. Figure 6 shows the IR spectrum of a metallized membrane by Cobalt following the 3 ^rd reduction, a blank membrane as a control.

Figure 7 shows the IR spectrum of a PVDF membrane radiografted with PAA and metallized with nickel after the bath ¹ chelation and after the 2 ^nd reduction, a PVDF membrane with virgin radiografted PAA as a control.

Figure 8 shows the IR spectrum of a PVDF membrane radiografted with PAA and metallized with nickel due to chelation ¹ bath, following the reduction ^st and following the 2 ^nd reduction, a PVDF membrane with radiografted blank PAA as a control. Figure 9 corresponds to the cyclic voltammetry implemented during the electrochemical reduction of Example V.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

In the examples which follow, various substrates have been treated according to the invention to lead to particular products and devices whose properties and applications are exposed. The examples presented are summarized in Table 1 below.

o

Table 1

In order to carry out precise measurements, the substrates have been cleaned with great care, the results have been successfully reproduced under less stringent conditions.

Unless otherwise specified, the substrates employed, when of the same type, have the same characteristics and have been obtained from the same supplier. In the protocols presented, the salt of

Mohr has been used to limit the homopolymerization of acrylic acid (AA).

The PVDF particles illustrating the examples can be prepared according to the method set forth in patent EP 1 454 927 corresponding to US Pat. No. 7,012,122.

The degree of grafting of the organic films on the various substrates was determined by a measurement of the weight gain observed after treatment.

I- Preparation of substrates

1-1 Using radio-grafting

I-I-a Heterogeneous Membranes

Initially, a polyvinylidene fluoride (PVDF) matrix (6 x 30 cm, 9 μm thick) was subjected to Xe heavy ion bombardment. The fluence varied from 5.10 ⁷ to 5.10 ¹⁰ ions per cm ² . This corresponds to a dose ranging from Gy to 1000 kGy. The irradiation angle was set at 90 °. This step allowed the creation of latent traces including radical species. The matrices prepared according to this modality can be used immediately or stored under an inert atmosphere, such as nitrogen, and generally cold (-18 ^° C.), for several months before their use.

In a second step, the irradiated matrix was brought into contact with AA in an aqueous solution, sparged with nitrogen for 15 min, containing from 20% to 80% by weight of acid and 0, 1% by weight of Mohr salt at 60 ^° C. for 1 hour with stirring. The same protocol was carried out with ethyl acetate as a solvent.

The membrane obtained was then extracted from the solution and then washed with water and extracted with boiling water using a Sohxlet apparatus for

24 h. It was then dried for 12 hours under high vacuum.

The grafting rate obtained by this protocol is generally between 10% and 300% by weight.

I-l.b Homogeneous membranes with electronic irradiation

Firstly, a PVDF matrix (6 × 30 cm, 9 μm thick) was subjected to electron irradiation. The dose varied from 50 to 150 kGy. The irradiation angle was set at 90 °. This step allowed the creation of radicals trapped within the crystallites of PVDF.

In a second step, the irradiated matrix was brought into contact with AA. For this, the matrix has been immersed in a solution, previously degassed, comprising from 20% to 80% by weight of acid in water (or ethyl acetate) and 0.1% by weight of Mohr salt at 60 ^° C. for 1 h with stirring. The resulting membrane was then extracted and treated as before.

The grafting rate obtained by this protocol is between 10% and 120% by weight.

I-l.c Membrane grafted on one side The electron irradiation was carried out as before.

In a second step, the irradiated matrix was placed, for a time between 10 min and 1 h, between two compartments, one of which contained a solution, previously degassed and then placed at 60 ^° C. with stirring, comprising 20% 80% by weight of AA in water (or ethyl acetate) and 0.1% by weight of Mohr salt. The resulting membrane was then extracted and treated as before. The grafting rate obtained by this protocol is between 1% and 30% by weight. The modification of only one of the faces has been confirmed by Fourier transform infrared (IR) spectrometry (FTIR).

I-l.d Microparticles

At first, PVDF microparticles with a mean diameter ranging from 1 to 8 μm were subjected to an electron irradiation whose dose varied from 50 to 150 kGy. In a second step, the microparticles were immersed in a solution, previously degassed, comprising from 20% to 80% by weight of AA as previously employed.

The microparticles obtained were then isolated by filtration on a frit of suitable size and then cleaned with water. Then, a boiling solution of sodium hydroxide at 0.1 N was added. The microparticles were then washed twice with boiling water and treated with a 1N HCl solution before being isolated by filtration. After drying for 12 hours under high vacuum, it was possible to note a grafting rate of between 10% and 120% by weight.

Nanoparticles PVDF nanoparticles with a mean diameter ranging from 20 to 200 nm were treated according to a protocol identical to that used for the microparticles, except that the grafting was carried out under ultrasound. The grafting rate found is between 10 and 120% by weight.

Homogeneous Membranes - UV Irradiation A PVDF membrane (2.15 cm × 3.8 cm,

13.68 mg) was fixed on a glass plate and the whole was degassed under nitrogen for 20 min. The assembly was then irradiated for 30 min using an excimer lamp placed at 7 cm and emitting incoherent radiation in the V-UV at 172 nm. An EPR analysis confirmed the presence of radicals in the PVDF. The membrane was then immersed in a solution containing 80% by weight of acrylic acid in water. After sparging for 15 minutes under nitrogen, the mixture was heated at 60 ^° C. for 1 h. The polymerization yield obtained is 260% after 18 hours of extraction using a Soxhlet apparatus and 2 hours of drying in a vacuum oven.

The modified membrane was analyzed for FTIR in ATR mode and the presence of the carbonyl band of acrylic acid was detected at 1703 cm- ¹ .

The membrane was also immersed in a saturated solution of copper sulphate in order to exchange the proton of acrylic acid and to verify by EDX whether the presence of Cu ²⁺ is observed in the thickness of the membrane. After analysis, it has been found that the polyacrylic acid is located throughout the thickness of the matrix.

The membrane has been modified in thickness.

I-l.g Membrane surface modification - UV irradiation

A PVDF membrane (1 cm x 4 cm x 9 microns) was placed in a tube supporting the thermal shock (Pyrex ^®) and was then degassed for 30 min and placed under nitrogen. After this period, the tube was placed 4 cm from the optical fiber of a UV lamp (320 to 500 nm) and four irradiations, of 15 min each, were successively carried out. After irradiation, the membrane was placed under ambient atmosphere for 10 min before being immersed in a solution of pure AA previously degassed and having undergone a sparge of nitrogen during the duration of the irradiation. The assembly was then degassed for 10 min before being immersed in a thermostat at 60 ⁰ C for 6 h.

The modified membrane extracted from the reaction medium was washed with water for 15 min in the presence of ultrasound or extracted with boiling water using a Soxhlet apparatus for 18 h and then dried under high vacuum.

The FTIR spectrum (ATR) of the membrane shows an absorbance peak at 1703 cm ^-1 characteristic of the C = O band of the poly (acrylic acid) Contact angle measurements were also made and confirmed a difference between the contact angles found before and after grafting, the membrane becoming more hydrophilic after the treatment.

The signal observed in EPR as a function of the irradiation time made it possible to show that the mechanism does not correspond to the creation of radicals but to an "activation" of the preexisting defects or impurities in the membrane which do not appear detectable before the irradiation.

In this case, the membrane has only been modified on the surface.

1-2 Use of chemical grafting

1-2. a Glass plate covered with gold

A solution of a diazonium salt was first prepared from 10 ml of a solution of 1-4 phenyldiamine 0.1 M in HCl (0.5 M), to which was added 10 ml 0.1 M NaNO 2 solution in water. To this salt solution of diazonium was added 200 mg of iron filings, then, after 5 min, 10 ml of AA.

A glass slide (3.8 x 0.7 x 0.1 cm) coated with a layer of chromium with a thickness of about 9 nm, followed by a layer of gold about 60 nm, previously cleaned under ozone for 10 min, was then introduced into the reaction medium for 2 h, before being rinsed with water and introduced into a sodium hydroxide solution at pH 9.5 in the presence of ultrasound in order to solubilize the ungrafted polyacrylic acid (PAA). The slide, after rinsing with water, was dried. The thickness of the layer formed is a few nanometers.

1-2. b Acrylonitrile butadiene styrene, polyamide and acrylonitrile butadiene styrene / polycarbonate plates

The protocol used for the gold - coated glass slide has been successfully applied to plates (4 x 1 x 0.25 cm) of acrylonitrile butadiene styrene (ABS), acrylonitrile butadiene styrene / polycarbonate (ABS / PC). ) and polyamide previously cleaned under ultrasound in a solution of soapy water and in a solution of 0.5M hydrochloric acid.

1-2. c Microparticles

A diazonium salt was prepared from phenyldiamine as previously indicated. According to a first protocol, after 5 min,

2 g of PVDF microparticles, of average diameter between 1 and 8 microns, were then introduced into the reaction medium for 2 h with stirring, under nitrogen and at room temperature. The microparticles thus obtained were then isolated by filtration and then rinsed with water before being washed with a sodium hydroxide solution (0.1 N) in the presence of ultrasound, rinsed twice with water, with a solution of HCl (0.1 N) then with water and finally dried under high vacuum for 12 h. According to a second protocol, after 5 min,

2 ml of AA were added, then, after 10 min, 2 g of PVDF microparticles were then introduced into the reaction medium which was placed under agitation for 2 hours under a nitrogen atmosphere and at room temperature. The microparticles thus obtained were isolated by filtration and then rinsed with water, washed with sodium hydroxide solution (0.1 N) in the presence of ultrasound for 5 min before being again isolated by filtration and rinsed twice with water, with a solution of HCl (0.1 N) then with water and finally dried under high vacuum for 12 h.

1-2. d Nanoparticles

Nanoparticles (1 g) could be treated according to the methods described for the microparticles.

The protocols have also been implemented on activated nanoparticles. Activation was achieved by first adding the nanoparticles to an alcoholic potash solution

(3 g of potassium hydroxide in 15 ml of ethanol absolute) at room temperature for 10 min. Subsequently, the nanoparticles were removed by filtration and then rinsed twice with ethanol and then with water until a neutral pH of the filtrate was obtained. This step has allowed the creation of unsaturated bonds of the type -CH = CF- on the surface of the nanoparticles thus allowing an "activated" surface for the grafting of a layer by the chemical process.

1-3 Oxidative Pretreatment of Substrates

Oxidative pretreatment was performed on different materials prior to their preparation. Different protocols have been implemented for substrates of ABS and ABS / PC plates.

1-3. a Reaction of Fenton from iron (II) sulphate

The samples were immersed in 25 ml of an aqueous solution of iron sulphate (3.47 g, 5.10 ^-2 mol) and sulfuric acid (10 ^-3 M). Five ml (6.2 × 10 ^-2 mol) 35% hydrogen peroxide in water were then added and the pH maintained at 3. After 25 min, the samples were rinsed with MiIIiQ water and exposed to ultrasound in water for 10 min before to be dried.

1-3. b Treatment with KMnO ₄

The samples were immersed in

25 mL of a solution of 0.75 g of potassium permanganate (5.10 ^-3 mol) in sulfuric acid (3.3 M).

After 15 min, the samples were rinsed with water MiIIiQ and exposed to ultrasound in water for 10 min before being dried.

II- Chelation of metal ions

Materials coated with chelating organic films were introduced into metal salt solutions for varying lengths of time, and infrared spectroscopic (IR) measurements before and after exposure confirmed the complexation. Table 2 below shows the Infra-Red band expressed in cm ^-1 for various metal ions.

Metallic ion Infra-Red Band (cm ^" )

Co ²⁺ 1633 1550

Cu ²⁺ 1611 1540

Fe ²⁺ 1631 1594 1545

Mn ²⁺ 1628 1546

Ni ²⁺ 1630 1548

Ag + 1712 1539

Table 2

The parameters used are shown in Table 3 below.

Table 3 The experiments were carried out with aqueous solutions (0.1 M) of the following salts: FeSO ₄ .7H ₂ O, CuSO ₄ .5H ₂ O, NiSO ₄ .7H ₂ O, CoSO ₄ .7H ₂ O, Mn (NO ₃₎ ₂ .4H ₂ O, NiSO ₄ .7H ₂ O, ₄ Agso. The pH of the solutions was buffered with a mixture CH ₃ COOH (0.1 M) / NH ₃ (0.6 M) or CH ₃ COOH (0.1 M) / NaOH (0.1 M) so that the functions carboxylic acid present on the substrate are in ionized form. The solution of AgSO ₄ was not buffered. During exposure, saline solutions were shaken and, for some, exposed to ultrasound (US). At the end of the exposure, the materials were rinsed with deionized water (18 MΩ, MiIIiQ), possibly in the presence of ultrasound. In the case of micro- and nanoparticles, these were extracted from the salt solutions by filtration before being rinsed in aqueous solutions and extracted.

Charged materials, i.e. having metal ions in complexed form, were dried under high vacuum after rinsing to facilitate EPR measurements.

At the end of the saline solution treatment, electron paramagnetic resonance spectra were realized (Bruker ER-200D spectrophotometer X band equipped with a helium and nitrogen cryostat for the acquisition of spectra at low temperatures ) on the micro- and nanoparticles after drying. Measurements have been made at 20 Kelvin and 293 Kelvin and have found that the response of these systems varies with temperature and temperature. that they follow a Curie law (super- and / or paramagnetic effect).

The results obtained for the chelation are similar with the samples having undergone oxidative treatment.

The step of preparing the chelating organic films on a substrate presented in I was also successfully performed simultaneously with the chelation step presented in II.

III- First cycle of reduction

The charged materials, previously prepared, were then treated with an aqueous reducing solution or by photochemistry to effect the reduction of metal salts within the films. The conditions are shown in Table 4 below.

Table 4 III-1 Chemical reduction

Reducing solutions employed corresponded to aqueous solutions of NaBH ₄

(0.1 M) at neutral or basic pH. In this case, the pH of the solution was modified using a solution of

NaOH (0.01 M).

The reduction was carried out at a temperature of between 50 and 80 ^° C. for 2 to 20 minutes. After reaction, the treated samples were rinsed with ethanol and with deionized water (18 MΩ, MiIIiQ), possibly in the presence of ultrasound. In the case of the microparticles and nanoparticles, these have been removed from the solutions by filtration before being rinsed in aqueous solutions and extracted therefrom. Each of the materials was then dried under high vacuum.

The reduction of metal ions was observed by following the evolution of the IR spectra of the materials.

At the end of this first reduction step, new electron paramagnetic resonance spectra were made on the micro- and nanoparticles (FIG. 1). Measurements have been made at 20 Kelvin and 293 Kelvin and have shown that the response of these systems varies with temperature and follows a Curie law (super and / or paramagnetic effect).

The materials, depending on the ions that have been chelated, have magnetic properties clearly observable to the naked eye. Indeed, the proximity to a magnet can move them both in solution and dry.

III-1 Photochemical reduction In the case of silver salts, the reduction was carried out by photochemistry, it is a photoreduction.

Different membranes were subjected to UV irradiation (320 to 500 nm) under ambient atmosphere or in aqueous NaCl solution (9 g / L), about 3 cm from the lamp, for 1 to 15 minutes.

The treatment leads to a browning of the membrane which, after analysis, corresponds to the metallization. The XPS analysis of the Ag 3d ^{5/2 band} has an energy of 368 eV corresponding to the presence in and on the silver membrane in Ag ⁰ metal form.

IV- Chelation / chemical reduction cycles In order to obtain homogeneous metal layers, the protocols described previously

(Chelation and reduction) were carried out again by alternating always a first phase of complexation followed by a phase of reduction. The number of complexation / reduction phases varies from 2 to 10 times. From a cycle, the metallization is detectable to the naked eye following the observed change on the material.

The experimental protocols are summarized in the following tables. To check the conductive nature of the deposited layers, the resistance was measured using a conventional ohmmeter, for substrates based on PVDF membranes (Results IV.1 to IV.5 below), in length and thickness. Different lengths were taken into account (0.2 - 0.8 and 2 cm). To check the mechanical strength of the layers that will follow, a test with adhesive tape was performed. It consists in sticking on the layer a piece of adhesive tape and then removing it from the layer. If the deposited layer leaves with the adhesive, the mechanical strength is considered bad. If the layer remains insensitive to the adhesive, the mechanical strength is considered good. The adhesive tape that was used is a high performance invisible adhesive tape, branded PROGRESS.

IV-I Creation of a homogeneous Ni metal layer on a PVDF radiografted PAA membrane

This example was made with different reducers. The conditions are summarized in Tables 5 and 6.

Table 5

Table 6

Polarized ATR-FTIR attenuated total reflectance spectroscopy made it possible to determine the presence of the proton on the COOH / COO ^{~ group} of the polyacrylic acid (FIG. 2). Indeed, the characteristic band of the carboxylic acid COOH of the polyacid acrylic around 1703 cm ^-1 is visible for the virgin membrane Once chelated by Ni ²⁺ ions

^(1st bath and ^2nd bath chelating) is the COO band ^"of the polyacrylic acid around 1542 ^{cm" 1} is observed. On the other hand, the deviation of the absorption baseline seems characteristic of the absorption of metals, and here of nickel.

On the XPS spectrum, the binding energy peak equal to 853 eV corresponds to nickel in its reduced form Ni ⁰ electrons of the layer 2p _3/2 . The peak at 856 eV highlights the presence of nickel oxide (Figure 3).

IV-2 Creation of a homogeneous Cu metal layer on a PVDF radiografted PAA membrane

Different reducers have been used in this example. The conditions are summarized in Tables 7 to 9 below.

VO

Table 7

90 O

Board

00

Table 9

In Figure 4, the characteristic band of the carboxylic acid COOH of polyacrylic around 1705 cm ^"1 is visible to the virgin membrane. After chelation of Cu ²⁺ ions (after ^3rd cut) is the band C00 ^~ polyacid acrylic around 1556 cm ^"1 which is observed. On the other hand, the deviation of the baseline of absorption seems characteristic of the absorption of metals, and here of copper. On the XPS spectrum, the solid and dotted line peaks at 933 and 953 eV confirm the presence of copper Cu ⁰ based on data from the literature on this metal (Figure 5). They correspond respectively to

E2p3 / 2 S t E2pl / 2 •

IV-3 Creation of a homogeneous Fe metal layer on a PVDF radiografted PAA membrane

The experimental conditions of this example are summarized in Table 10 below.

10 00

15

Table 10

20

IV-4 Creation of a Co Coated Metal Coat on PAA Radiografted PVDF Membrane

The experimental conditions of this example are summarized in Table 11 below.

00 Ul

Table 11

6, the characteristic band of the carboxylic acid COOH of polyacrylic around 1705 cm ^"1 is visible to the virgin membrane. After chelation of Co ²⁺ ions (after ^3rd cut) is the band ^~ C00 polyacrylic acid around 1545 cm ^-1 which is observed. On the other hand, the deviation of the baseline of absorption seems characteristic of the absorption of metals, and here of cobalt.

IV-5 Creation of a homogeneous Ni metal layer on a single face of a PAA radiografted PVDF membrane

The experimental conditions of this example are summarized in Table 12 below.

Table 12

Figure 7, on the surface with PAA, the characteristic band of the carboxylic acid COOH of polyacrylic around 1707 cm ^"1 is visible to the virgin membrane. After chelation of Ni ²⁺ ions ^(1st and ^2nd reduction bath ) is the band COO ^"of polyacrylic around 1540-1542 ^{cm" 1} is observed.

On the other hand, the deviation of absorption baseline seems characteristic of the absorption of metals, and here of nickel. As expected, the presence of the band characteristic of the COOH / COO ^{~ group} of the PAA is practically not observed (FIG. 8). On the side without PAA, some traces remain and this with the wave numbers described previously. Metallization is not observed at all.

This example highlights the importance of AAP. Without PAA chelation, there is no metallization.

IV-6 Creation of a homogeneous Ni metal layer on a PAA chemistry-grafted ABS plate

The experimental conditions of this example are summarized in Table 13 below, the baths employed were developed on the basis of industry standards.

00

10

15

Table 13

IV-7 Creation of a homogeneous Ni metal layer on a PAA chemistry-grafted ABS / PC plate

The experimental conditions of this example are summarized in Table 14 below.

VO

10

15

Table 14

20

IV-8 Creation of a homogeneous Ni metal layer on a PAA chemically grafted polyamide plate

The experimental conditions of this example are summarized in Table 15 below. example are summarized in Table 15 below.

VO

10

15

Table 15

IV-5 Creation of a homogeneous Cu metal layer on a plate on ABS / PC plates and PAA-chemically grafted PCs having undergone oxidative treatment

The experimental conditions are summarized in Tables 16 to 18.

Fenton or KMnO4 pretreatments improve the grafting and therefore the properties of the treated surfaces.

Table 16

VO

Table 17

Pretreatment KMnO4 + Fenton

KMnO4 C reagent (mol / L) Remarks

KMnO4 0.2 Same protocol as patent

Sulfuric acid H ₂ SO ₄ 2, pretreatment Graftfast

Table I i

Fenton C reagent (mol / L) Remarks

Iron salt FeSO ₄ , 7H ₂ O 0.42

Same protocol as patent

Sulfuric acid H ₂ SO ₄ 0.83.10 ^" pretreatment Graftfast

H2O2 oxygenated water

Chelation bath

Reagents chelation bath Cf

See (g / L) Remarks (mol / L)

CuSO ₄ metal salt, 5H ₂ O 0.1 6.4

Stable bath for several days

Same solution for the 3 baths

Acetic acid CH ₃ COONa 0.1 chelation

NH base, 0.6 /

Bath of reduction

VO

See pH Remarks (mol / L) c (g / 1)

Reduction No.1 Dimethylaminoborane 0.24 14.4 9-10 Each reduction is

Reduction N ° 2 Dimethylaminoborane Same solution followed by rinsing

Reduction N ° 3 Dimethylaminoborane 0, 97 57,6 9-10 Water MQ + US

Metallic bath

Reagents ^m (g) per 100 mL c (g / 1) Operating conditions

CuSO ₄ , 7H ₂ O 0.5

Tartrate of Dissodium 2, 96 25

T = 30 - 35 ° C for 10 minutes

C ₄ H ₄ Na ₂ O ₆ pH = 12-12.5

0.5 NaOH

Formaldehyde

1 mL 10 mL / L HCHO

Operating conditions

Chelation Reduction Chelation Reduction Chelation Reduction Bath

KMn04 Fenton N ° l N ° l N ° 2 N ° 2 N ° 3 N ° 3 metallization

J-soaking 15 25 10 10

(min) T ( ⁰ C) TA TA TA 50 - 80 ^° C TA 50 - 80 ^° C TA 50 - 80 ^° C 30 - 35

V- Cycles of chelation / electrochemical reduction

A PVDF membrane radiografted with PAA having undergone a first chemical chelation / reduction step with a nickel salt was used as the measuring electrode. The electrochemical system put in place consisted of a saturated KCl calomel reference electrode and a graphite counter electrode.

The electrodes were soaked in a solution of CuSO ₄ at 10 g / L, the initial potential was about 0.1 V.

A voltammetry cycle of up to -0.6 V in 60 s was imposed on the system. During the voltage rise, the experiment was stopped at around -0.35 V (Figure 9).

This cycle showed the deposition of copper on the measuring electrode. Indeed, the current increased when the voltage decreased and the copper was deposited on the membrane serving as measuring electrode. Copper reduction took place at the measuring electrode.

Confirmation could be made visually. In fact, the membrane after the electroreduction had a "copper" color.

Claims

1) Process for preparing a metallized substrate comprising the steps of: a) grafting onto said substrate a polymer-type compound optionally having a group (or a structure) capable of chelating at least one metal ion; b) optionally subjecting said polymeric compound to conditions permitting its functionalization by a group (or a structure) capable of chelating at least one metal ion; c) providing said polymer-type compound capable of chelating at least one metal ion obtained after step (a) or (b) in contact with at least one metal ion; d) subjecting the polymer-type compound obtained in step (c) to conditions for reducing said chelated metal ion (s); e) optionally repeating steps (c) and (d) until a metallized substrate is obtained.

2) Method according to claim 1, characterized in that the grafting of said step (a) is a graft selected from the group consisting of chemical grafting, electrografting and radiochemical grafting. 3) Process according to any one of claims 1 or 2, characterized in that said grafting step (a) involves a chemical grafting comprising the steps of: ai) contacting the substrate to be metallized with a solution Si comprising at at least one adhesion primer and optionally at least one monomer other than the adhesion primer and radically polymerizable; bi) subjecting said Si solution to non-electrochemical conditions allowing the formation of radical entities from said adhesion primer.

4) Method according to any one of claims 1 or 2, characterized in that said grafting step (a) involves electrografting comprising the steps of: a ₂ ) contacting the conductive or semiconductor substrate with a solution S2 comprising at least one adhesion primer and optionally at least one polymerizable monomer different from said adhesion primer and radically polymerizable; b ₂ ) biasing said substrate to an electric potential that is more cathodic than the reduction potential of the adhesion primer implemented in step (a ₂ ), the order of steps (a ₂ ) and (b ₂ ) being arbitrary . 5) Method according to any one of claims 1 or 2, characterized in that said grafting step (a) involves a radiografting comprising the steps of: a) irradiating a polymeric matrix-type substrate; b3) bringing the irradiated substrate obtained in step (β3) into contact with at least one adhesion primer and / or at least one radically polymerizable monomer.

6) Process according to claim 5, characterized in that said step (as) consists in subjecting the polymer matrix to an electron beam.

7) Method according to claim 5, characterized in that said step (β3) comprises subjecting the polymer matrix to bombardment with heavy ions and in particular by a heavy ion beam.

8) Method according to claim 5, characterized in that said step (β3) consists of subjecting the polymer matrix to UV radiation.

9) Process according to any one of claims 3 to 8, characterized in that said adhesion primer is a cleavable aryl salt selected from the group consisting of aryl diazonium salts, aryl salts of ammonium salts of aryl phosphonium, aryl iodonium salts and aryl sulfonium salts.

10) Process according to any one of claims 3 to 9, characterized in that said adhesion primer is a compound selected from the group consisting of 4-nitrobenzenediazonium tetrafluoroborate, tridecylfluorooctylsulfamylbenzene diazonium tetrafluoroborate, phenyldiazonium tetrafluoroborate, 4-nitrophenyldiazonium tetrafluoroborate, 4-bromophenyldiazonium tetrafluoroborate, 4-aminophenyldiazonium chloride, 2-methyl-4-chlorophenyldiazonium chloride, 4-benzoylbenzenediazonium tetrafluoroborate, 4-cyanophenyldiazonium tetrafluoroborate, 4-tetrafluoroborate -carboxyphenyldiazonium, 4-acetamidophenyldiazonium tetrafluoroborate, 4-phenylacetic acid diazonium tetrafluoroborate, 2-methyl-4 - [(2-methylphenyl) diazenyl] benzenediazonium sulfate, 9,10-dioxo-9-chloride , 10-dihydro-1-anthracenediazonium, 4-nitronaphthalenediazonium tetrafluoroborate and naphthalenediazonium tetrafluoroborate.

11) Process according to any one of claims 3 to 10, characterized in that the radical polymerizable monomer (s) is (are) chosen from the monomers of formula (II) next : in which the groups R 1 to R ₄ , which are identical or different, represent a non-metallic monovalent atom such as a halogen atom, a hydrogen atom or a saturated or unsaturated chemical group, such as an alkyl or aryl group, a group

-COOR ₅ or -OC (O) R ₅ in which R ₅ represents a hydrogen atom or a C 1 -C 12 and preferably C 1 -C 8 alkyl group, a nitrile, a carbonyl, an amine or an amide.

12) Process according to any one of claims 3 to 11, characterized in that the (or) monomer (s) polymerizable (s) radical is (are) chosen (s) from among the group consisting of esters vinyl such as vinyl acetate, acrylic acid, acrylonitrile, methacrylonitrile, methyl methacrylate, ethyl methacrylate, butyl methacrylate, propyl methacrylate, hydroxyethyl methacrylate, methacrylate hydroxypropyl, glycidyl methacrylate and their derivatives; acrylamides and especially methacrylamides of aminoethyl, propyl, butyl, pentyl and hexyl, cyanoacrylates, di-acrylates and di-methacrylates, tri-acrylates and tri-methacrylates, tetra-acrylates and tetra-methacrylates ( such as pentaerythritol tetra-methacrylate), styrene and its derivatives, parachlorostyrene, pentafluorostyrene, N-vinylpyrrolidone, 4-vinylpyridine, 2-vinylpyridine, vinyl halides, acryloyl or methacryloyl, di-vinylbenzene (DVB), and more generally vinyl or based on crosslinking agents. acrylate, methacrylate, and their derivatives.

13) Process according to any one of the preceding claims, characterized in that said group (or said structure) capable of chelating (complexing) at least one metal ion is chosen from the group consisting of a group of amines, amides, ethers, carbonyls, carboxyls, carboxylates, phosphines, phosphine oxides, thioethers, disulfides, ureas, crown-ethers, aza-crowns, thio-crowns, cryptands, sepulcrands, podands, porphyrins, calixarenes, pyridines, bipyridines, terpyridines, quinolines, orthophenantroline compounds, naphthols, iso-naphthols, thioureas , siderophores, antibiotics, ethylene glycol, cyclodextrins, as well as the molecular structures substituted and / or functionalized from these functional groups, and / or one or more complex cavity (s) ante (s) type redox locks.

14) Method according to any one of the preceding claims, characterized in that, in said step (c), the metal ion is selected from the group consisting of Ag ⁺ , Ag ²⁺ , Ag ³⁺ , Au ⁺ , At ³⁺ , Cd ²⁺ , Co2 + Cr2 + Cu Cu2 + Fe2 + Hg2 + Mn2 + Ni2 + Pd ⁺ Ptf Ti 'and Zn ²⁺

15) Method according to any one of the preceding claims, characterized in that said step (d) of reduction is a chemical reduction, photoreduction or electrochemical reduction.

16) Process according to any one of the preceding claims, characterized in that said step (d) is a chemical reduction step implementing a reducing solution S ₅ comprising a reducing agent chosen from the group consisting of sodium tetrahydroborate ( NaBH ₄ ), dimethylaminoborane (DMAB) and hydrazine (N 2 H 4).

17) Method according to any one of the preceding claims, characterized in that said step (d) is an electrochemical reduction step implementing an electrochemical cell in which the substrate obtained following step (c) serves as an electrode in the presence of a reference electrode and a counter-electrode.

18) Substrate obtainable following step (a) or step (b) of a process as defined in any one of claims 1 to 17. 19) Use of a substrate according to claim 18, for complexing at least one metal ion and in particular for purifying a solution that may contain at least one metal ion.

20) Substrate obtainable following step (c) of a process as defined in any one of claims 1 to 17.

21) Use of a substrate according to claim 20 as antifungal or as an antibacterial agent.

22) Substrate obtainable by a process as defined in any one of claims 1 to 17.

23) Substrate according to claim 22, characterized in that it is in the form of a valve element, an automobile accessory, dishes, a container for food products, cosmetic or therapeutic or ( micro) particles used in cosmetics.

24) Substrate according to any one of claims 22 or 23, characterized in that it is magnetic.

25) Substrate according to any one of claims 22 to 24, characterized in that presents a biological or biologically active molecule immobilized on its surface.