EP2524014B1 - Surface modification system for coating substrate surfaces - Google Patents

Description

The invention relates to a surface modification system for the coating of substrate surfaces with a metallic character, wherein a dispersion of polymer-protected particles is used. The interaction of the particles with the substrate surface and the anchoring of the polymer chains result in an adhesion promoter layer to which further target molecules can be bound by charge interaction. Of particular interest for e.g. Medical devices is the use of biocompatible polymers.

State of the art

The use of nanoparticles for coating electrodes is in WO2009046382 A2 described. Here, the preparation of a primary and secondary nanoparticle layer on metal surfaces is described, wherein the primary nanoparticle layer has better adhesion properties to the metal surface of the electrode than the secondary nanoparticle layer, which in turn forms a compound with the primary nanoparticle layer.

The US2009087644 A1 discloses a method for coating substrates with a layer of functionalized nanoparticles, wherein the substrate is coated in a solution with a polymeric binder containing the functionalized nanoparticles by immersion. Subsequently, a further coating operation is carried out with a second layer of functionalized nanoparticles, whereby a gradient with respect to a desired material property is formed.

The US2007036510 A1 discloses methods of making a plastic packaging material for microelectronic products wherein a layer containing nanoparticles is in contact with the substrate. By using nanoparticles, various properties of the packaging material can be adjusted for the respective application.

In US20040055420 describes the adsorption of dispersed polymer-stabilized nanoparticles on electrodes. The deposition methods include electrophoretic as well as thermal processes. A subsequent etching process increases the surface roughness of the electrode and thus its efficiency.

Principal mechanisms of electrophoretic particle deposition on substrate surfaces are described in the book of Aldo R. Boccaccini, Jan B. Talbot et al (Electrophoretic deposition, fundamental and applications, Electrochemical Society, Electrodeposition Division, United Engineering Foundation US, 2002 ).

The field of silver nanoparticles has been around for more than a century ( M. Faraday, Philos. Trans. R. Soc. London 1857, 147, 145 ) processed.

The stabilization of silver nanoparticles by poly (vinylpyrrolidone), PVP, continues through Xia et al. (Angew Chem 2009, 121, 62 - 108 ). In addition, chemical and physical shape control in the synthesis of metal nanocrystals will be discussed. In addition, the interaction of nanoparticles of platinum or silver with iron, a major constituent of stainless steel, is described.

Further stabilizing substances for metallic nanoparticles are electron donor compounds in which the electron-rich groups are arranged in a manner favorable for the stabilization of nanoparticles. By way of example, the derivatives of polyacrylic acid ( Falletta et al J. Phys. Chem. C, 112 2008, 11758-11766 ), Poly (meth) acrylic acid ( Dubas et al Talanta 76 2008 29-33 ) or polyacrylamide ( Bonini et al Langmuir 24 2008 12644-12650 ) called.

In a work of Charlot et al (J Mater Chem, 19, 2009, p. 4117 ) describes the use of 3,4-dihydroxyphenylalanine (DOPA) stabilized silver nanoparticles for coating stainless steel.

From the above literature it is also clear that a dispersion of metal particles in various media (aqueous or organic) may be present.

To functionalize metal materials for industrial applications or for medical technology a variety of methods are used. Mainly paints, dip, flow and roller coating or vapor deposition strategies (e.g., thermal spray, cold vapor deposition, ultrasonic technique, Parylene coating, PTFE coating, etc.) are used.

For the deposition of metals or colloidal substances (eg water-soluble dyes) on metal substrates, the electrophoretic effects-based method of electroplating is used ( S. Paul, Surface Coating, Science and Technology, J. Wiley Ltd, 1996, p. 497 ). With this metal components of different and complex geometry can be processed with low material losses. Furthermore, the use of water-soluble inks reduces solvent emissions.

The stability and homogeneity of the coating is determined to a large extent by the purity of the metal surface. Therefore, washing or etching steps are usually integrated into the coating method. In this case, chlorine-containing solvents, (chromium-phosphorus, hydrochloric and sulfuric) acids or alkaline media are used. To prepare methods of electrodeposition, the metal surface is often provided with a phosphate coating. A large number of methods are available for this, but only a few result in a homogeneous, extremely thin and microcrystalline coating ( G. Reinhard, Prog. Org. Coat., 15, 1987, p. 125 ).

The preparation of the primary and secondary nanoparticle layers on metal surfaces as in WO2009046382 A2 described without the formation of a stable adhesion promoter layer by a pinching mechanism between the substrate, particle layer and stabilizing polymers.

Of the in the pamphlets US2009087644 A1 and US2007036510 A1 no direct conclusion can be drawn on the invention described herein. None of the documents contain information or hints which indicate a possible improvement of the adhesion mediation to target molecule layers by nanoparticle presence.

In the US20040055420 described methods are used only to increase the surface roughness of electrodes. Use of surface modification to immobilize target molecules is not claimed in the reference.

For paints or vaporization strategies, substances are used that are questionable or complicated from an ecological point of view. Although the use of acrylates, epoxides, ethylenes, and vinylenes is widespread, it involves the question of immobilization / reaction of the functional groups and sensitization of users. In addition, vaporization methods are associated with a complex instrument design.

Furthermore, in conventional methods, the metal surfaces must be treated prior to application of coating reagents. For this purpose, either etchants or detergents are used, which increase the disposal costs of the respective processes.

The disadvantage of electroplating is that in the anodic reaction considerable amounts of bases are needed to generate the necessary negative charges on the macromolecules used ( CAMay JPT 43, 1971, p. 43 ). Also, the generation of oxygen has a detrimental effect on the performance of the resulting coating (MR Sullivan 38, 1966, p.424). Discharge phenomena, together with gas generation, present problems with cathodic galvanization ( JRSmith, DWBoyed JCT 60, 1988, p.77 ).

The method described by Charlot et al. Is based on the statement that the adhesion promoter is attributed to the DOPA copolymer used. The silver nanoparticles are only used as a source of herbicides.

The object of the present invention is therefore to provide an improvement in the adhesion promotion on a surface with a metallic character by coating reagents and the further functionalization of the adhesion promoter layer. Due to the chemical and physical properties of metal surfaces, the wetting and adhesion by adhesion promoters and thus the homogeneous and stable coating is problematic. In addition, the environmental compatibility and the health protection is a challenge.

The object is achieved by a method according to the main claim. Advantageous embodiments are given in the appended claims. The object is further achieved by a coated metal surface according to claim 15.

According to the invention, the object is achieved by a method for coating a substrate surface by means of dispersed particles. The particles are first dispersed in a solvent with the aid of a stabilizing polymer. Thereafter, the substrate surface to be coated is wetted with the stabilized particle solution, wherein a fixation of the polymer chains takes place in the spaces between the metal surface and particles by a clamping mechanism. Theoretically, this substrate particle binding can be formed by penetration / diffusion processes of the particles into the surface. By collapsing and aggregating the colloidal system, a stable particle layer is formed on the substrate surface.

In a subsequent step, after completion of the coating process, the unbonded particles are removed by washing with a solvent. If a further stabilization of the surface modification system is desired, then stabilizing reactions can be carried out. For this purpose, additives such as free-radical initiators and / or crosslinkers and / or complexing agents and / or surfactants can be helpful. Furthermore, stabilization can be brought about by the formation of interpenetrating networks (IPN).

In order to create interaction centers for the subsequent coating with target molecules, a generation of ionic charges now takes place on the coated substrate surface. These can be prepared by means of chemical reactions known to those skilled in the art from organic or polymer analog chemistry. Alternatively, particle systems with ionically charged stabilizing polymers can also be used.

Another possibility for the immobilization of target molecules is the application of stereo-complexation. Such complexes arise from the interaction of (D, L) stereoisomers. Another possibility for the immobilization of target molecules is the application of hydrogen bonds.

Hydrogen bonds also play a major role in thermo-reversible hydrogels. Due to the system collapse upon temperature increase, adhesion promoter layers can be produced using thermoreversible hydrogels, on-demand. The final step is the drying of the coated substrate surface.

In the context of the invention, a substrate surface with a metallic character is understood to mean an electrically conductive surface. The substrate surface may be part of a metallic article of various geometries (e.g., cable, plate, rod, tube, ball, tissue, stent-like constructs), a porous wafer, a fiber composite, or the like. The substrate surface may have a flat or structured surface, which allows the adhesion of the surface modification system. The substrate surface may comprise one or more elements selected from groups 3 to 16 and the lanthanides of the Periodic Table of the Elements, their isotopes, salts, as well as mixtures, alloys, etc. thereof.

In a further embodiment of the invention, the adhesion promoter layer can be stabilized by initiating crosslinking steps. For this purpose, crosslinking agents and polymerization initiators are added to the adhesion promoter system. Addition of radical initiators and / or crosslinkers may be helpful in initiating polymerization reactions (eg, radical or condensation reaction) as well as polymer-analogous reactions (e.g., nucleophilic or electrophilic reactions). Additional options for such stabilization are provided by beta and gamma ray crosslinking steps.

In another embodiment of the invention, technologies (such as lithographic process etching techniques) may be employed to provide more or less targeted structural properties to affect surface roughness. Such a structuring method can bring about an influence on the surface wetting.

In another embodiment of the invention, stabilization of the primer layer may be enforced by rinsing the particle destabilizing LSM. The rinse causes a collapse of the particles and thus increases the interaction in the clamping complex substrate-particle polymer.

According to the invention, the particles used are metal particles / metal alloy particles / metal oxide particles. The particles may contain one or more elements selected from groups 3 to 16 and the lanthanides of the Periodic Table of the Elements, their isotopes, salts, as well as mixtures, alloys, etc. thereof. The particles can have a wide variety of shapes and structured surfaces. In order to enable the necessary processes for the preparation of a desired surface modification system and a sufficient stability of the dispersion, according to the invention the dimensions of the particles used are in the micron / submicron or nanometer range. Particles of this size can be used for surface penetration / diffusion processes and are more easily dispersed and stabilized by stabilizing reagents such as e.g. Protect polymers from premature coagulation.

In a further embodiment of the invention, in addition to the electrophoretic deposition (eg EPD) also chemical in situ deposition (eg in situ nano-particle deposition system (NPDS), combinations of salts of reducible metals (eg Au, Ag or Fe) and reducing agents z. For example, poly-8-hydroxyquinolines (Mahmoud et al 2009, Deraeve et al 2007) or Brunox epoxy with polymerization initiators) are used.

In a further embodiment of the invention, the particles are at least partially coated with one or more colloid-stabilizing polymers. Thus, a differentiated modification e.g. be made possible on the uncoated particle sections.

In a further embodiment of the invention, the particles have a functionalization by the colloid-stabilizing polymers used. These functionalities can also be generated by a subsequent reaction step. The functionalization is necessary for a stable and homogeneous Represent coating with target molecules.

In another embodiment of the invention, the dispersion of inorganic particles with organic particles, e.g. Isobutylcyanoacrylaten or gelatin, added. By means of such a formulation composition, it is possible to coimmobilize particles of very different chemical properties and to create a wide variety of functional layers.

According to the invention, the polymer used is a biocompatible polymer or hydrogel-forming polymer. This is of particular interest for biomedical and biotechnological applications. For example, such hydrophilic or bio-functional surfaces can be displayed on medical devices. In a further embodiment of the invention takes place after the coating of the substrate surface with the functionalized particles, a loading of target molecules, wherein the interaction between the primer layer and target molecule can be ionic, complex, chelate nature. Further interactions may be due to interpenetrating networks (IPN), hydrogen bonds, or other electrostatic effects.

In another embodiment of the invention, a combination of collapsed particles and interpenetrating networks is used, thereby reducing the susceptibility to stress / cracking of the subsequently applied coating with target molecules. In addition to the charge-charge interactions, interpenetrating networks (IPNs) can lead to greater flexibility at the phase boundary adhesion promoter / target molecule. In addition, the collapsed particles act as centers of stress relaxation and thereby reduce the susceptibility to stress / cracking of the subsequently applied coating with target molecules.

In a further embodiment of the invention, so-called 'Pfropff reactions, as exemplified in the documents, are used for the coupling of target molecules US2010087343A1 . US2009123772A1 or US6369168B1 described used. Thereby For example, functional layers such as sliding films can be produced on the polymer materials.

In a further embodiment of the invention, the coated substrate surface is functionalized with biologically active molecules, e.g. Antibodies and nucleotides used. Furthermore, antiseptic monomers, such as e.g. Isobutylcyanoacrylate, be reacted on the surface. Further polymer-analogous reactions can be used to show additional surface properties.

In a further embodiment of the invention, the coated substrate surface is used for functionalization with organic (nano) particles. If e.g. like the isobutylcyanoacrylate particles used in the pharmaceutical industry, their high specific surface area can produce antiseptic coatings with significantly reduced material consumption. At the resulting surface further target molecules can be reacted.

In a further embodiment of the invention, the coated substrate surface is used for functionalization with glucan-like oligomers / polymers such as cellulose, starch, heparin, chitosan, hyaluronic acid, etc. Such coatings have a high degree of biocompatibility.

In a further embodiment of the invention, the coated substrate surface is used to immobilize functional coatings (eg non-reflective, antifouling, lubricating film, etc); synthetic / natural target molecules, hydrogel polymers; Drugs; peptides; antimicrobial agents; lipids; polysaccharides; biologically active molecules such as antibodies, nucleotides, enzymes, signal peptides, fluorescent / phosphorescent dyes, minerals, nanoparticles; Clay minerals or activated carbon eg for water treatment; clathrates; Cyclodextrin and other supramolecules, such as for detoxification or endotoxin clearance; electrically conductive metal surfaces, photoelectrically active surfaces, etc. used.

• Fig. 1 eine beispielhafte Strategie zur Beschichtung von Oberflächen mit metallischem Charakter mit Hilfe einer nanopartikulären Metalldispersion zur Darstellung einer Haftvermittlerschicht. Durch die Erzeugung ionischer Eigenschaften können in nachfolgenden Applikationsschritten (bio)-aktive Substanzen durch ionische Wechselwirkung immobilisiert werden.
• Fig. 2 eine beispielhafte Strategie zur Beschichtung von Metalloberflächen mit Hilfe einer nanopartikulären Metalldispersion zur Darstellung einer ionisch geladenen Haftvermittlerschicht, wobei durch nachfolgende Applikationsschritte (bio)-aktive Substanzen durch ionische Wechselwirkung immobilisiert werden.

The invention will be explained in more detail with reference to some embodiments. Show in:

• Fig. 1 an exemplary strategy for coating surfaces with a metallic character with the aid of a nanoparticulate metal dispersion for the preparation of a primer layer. By generating ionic properties (bio) -active substances can be immobilized by ionic interaction in subsequent application steps.
• Fig. 2 an exemplary strategy for coating metal surfaces with the aid of a nanoparticulate metal dispersion for the preparation of an ionically charged adhesion promoter layer, wherein (bio) -active substances are immobilized by ionic interaction by subsequent application steps.

Embodiment 1

The substrate to be coated is immersed in a stabilized dispersion of metal particles. The temperature of the dispersion may be room temperature. The dispersion can also be heated. The reaction time can vary over a period of 180 minutes. As in Fig. 1 show, in the manner just described, colloidal polymer-stabilized metal particles ( Fig. 1 , 104) to the metal substrate surface ( Fig. 1 , 100). By aggregation and collapse ( Fig. 1 , Step 101) of the metal structures results in an additional metal layer with polymer chains immobilized by clamping complexes ( Fig. 1 , 105). This step results in a coating acting as a primer, which serves as a basis for further functional coatings.

After removal of the substrate from the dispersion and prior to anchoring various target molecules on the modified substrate, washing is carried out with a suitable solvent. As in Fig. 1 Step 102, a modification of the primer layer is performed. If the metal particle dispersion is stabilized with an amidic polymer such as, for example, polyvinylpyrrolidone or polyacrylamide, amino or carboxylate functions (in the alkaline medium) can be obtained by hydrolysis ( Fig. 1 , 106) are generated. By pH Variation can also change the charge of the surface. Finally, oppositely charged target molecules can be immobilized ( Fig. 1 , Step 103). Subsequently, the drying of the applied coating ( Fig. 1 , 107).

Embodiment 2:

The substrate to be coated is immersed in a stabilized dispersion of metal particles. The temperature of the dispersion may be room temperature. The dispersion can also be heated. The reaction time can vary over a period of 180 minutes. As in Fig. 2 in the manner just described adsorb ionically charged colloidal polymer-stabilized metal particles ( Fig. 2 , 203) to the metal substrate surface ( Fig. 2 , 200). By aggregation and collapse ( Fig. 2 , Step 201) of the metal structures results in an additional metal layer with polymer chains immobilized by clamping complexes ( Fig. 2 , 204). This step results in an ionically charged coating acting as an adhesion promoter, which serves as the basis for further functional coatings.

After removal of the substrate from the dispersion and prior to anchoring various target molecules on the modified substrate, washing is carried out with a suitable solvent. If the metal particle dispersion is stabilized with a polymer such as, for example, polyacrylic acid (PAA), negatively charged functions such as carboxylate functions can be generated in the sufficiently alkaline medium and charged target molecules can be immobilized ( Fig. 2 , Step 202). Subsequently, the drying of the applied coating ( Fig. 2 , 205).

In a further embodiment, the surface modifications according to the invention represent the possibility of incorporation of drug systems or coupling of specific ligands. In this way, biocompatible surfaces can be created.

In a further embodiment, the surface modification system of the invention is used for therapeutic and analytical applications. Immobilization of hydrophilic / lubricious / antimicrobial / abrasion-resistant / heat-resistant / corrosion-stable / fracture-resistant substances takes place and / or other functional coatings. Immobilization may be followed by the goal of altering the physical properties of the support material, such as waterproofness, mechanical strength, chemical resistance, light fastness, abrasion resistance, gas and moisture permeability, design, appearance, feel, surface design, and bulk. The method is therefore also suitable for solving technical problems through biologically inspired solutions (bionics).

In another embodiment, the surface modification system of the present invention is used to decorate the substrate surface with charge carriers such as ionic biomolecules (e.g., glycosaminoglycans). So biocompatible or antifouling surfaces can be produced.

In a further embodiment, the surface modification system of the present invention is useful for functionalizing the substrate surface with biologically active molecules, e.g. Antibodies and nucleotides used. This is of particular interest in analytical medical technology.

In a further embodiment, the surface modification system according to the invention is used to functionalize the substrate surface with fluorescence / phosphorus molecules for fluorescence / phosphorus determination systems.

In another embodiment, the magnetic particle surface modification system of the present invention is used for medical imaging systems for malignant tissue examination.

In a further embodiment, the surface modification system according to the invention is used for the immobilization of lipid membrane viscoses (liposomes) or polymeromas as biocompatible / biodegradable active substance carrier or biological membrane on the substrate surface.

In another embodiment, the surface modification system of the present invention is used to immobilize surfactant oligomers together with lecithin to solubilize cholesterol on the substrate surface.

In a further embodiment, the surface modification system of the invention is used to apply a drug-release coating on the substrate surface at a defined rate of release.

In another embodiment, the surface modification system of the present invention is used to immobilize superparamagnetic iron oxide particles for metastasis elimination on the substrate surface.

In a further embodiment, the surface modification system according to the invention is used for decoration of water pipes with antimicrobial agents for outdoor use for the disinfection of water. Compared to the prior art, e.g. Dissolution of Ag salt tablets in the drinking water, thus a considerable simplification of the water treatment is achieved.

In a further embodiment, the surface modification system according to the invention is used to prepare metal / polymer systems with defined structures by laser-chemical treatment of immobilized metal chelates.

In a further embodiment, the surface modification system according to the invention is used for embedding clay minerals or activated carbon for water treatment (detoxification).

In a further embodiment, the surface modification system according to the invention is used for further industrial painting or decorative design. For this novel or conventional paint systems may be considered.

In a further embodiment, the surface modification system according to the invention is used for embedding fuel cell components.

In a further embodiment, the surface modification system according to the invention is used for embedding functional (nano) particles (magnetic, light-emitting, etc.); solid-state hosts (eg polyurethane / silica ORMOSILs) used to store LASER dyes, etc.

The incorporation of redox-capable systems (eg iron particles) can enable redox polymerization on the surface. The stabilization of the iron oxide particles is achieved so far by a coating with polymers such as dextran (Ferridex ^®), carboxydextran (Resovist ^®), albumin and starch or a liposomal envelope. These represent a possibility for forming interactions such as interpenetrating networks (IPN) with a potential coating system.

In a further embodiment, the surface modification system according to the invention is used as a lubricant substitute in ball bearings.

In a further exemplary embodiment, the surface modification system according to the invention is used for coating composite materials with sufficient conductivity, such as, for example, carbon black-reinforced plastics (CFRP), short-fiber reinforced metals, so-called metal matrix composites (MMC).

In a further embodiment, the surface modification system of the invention is used to coat analytical equipment such as e.g. Chromatography columns used. As a result, novel filling systems can be created.

In a further embodiment, the surface modification system according to the invention is used for the adhesion mediation between components of the same or different material / surface properties.

In a further embodiment, the surface modification system according to the invention is used for coating materials which are used in concrete constructions similar to the irons.

In another embodiment, the surface modification system of the present invention is used to coat materials used in the testing of plastics materials (e.g., metal strips in natural rubber)

In a further embodiment, the surface modification system according to the invention is used for the production of carbide / nitride or similar abrasion-resistant / oxidation-stable / protective Layers (as shown, for example, by physical vapor phase deposition). Here, the stabilizing polymer by (partial) decomposition, for example, serve as a carbon / nitrogen or other elementary source. Strength-enhancing substances could also be obtained by additional additives, such as after in the document DE102004014076B3 Further, the polymer phase may be used as an intermediate layer for stress absorption. The abrasion-resistant systems can be used for example on metallic cutting tools, which have ceramic-like properties on the surface after the appropriate treatment. Abrasion resistant layers are also interesting in terms of computer drives. An ever-increasing data density on hard disks requires better resolution and better mechanical stability of the surfaces. Abrasion-resistant surfaces are therefore of great interest in order to avoid damage to the drive.

In another embodiment, the surface modification system of the invention is used in combination with stimuli-responsive adhesion mediators (with stimuli such as temperature, electromagnetic radiation, etc.) for on-demand adhesions. Such may e.g. as adhesive joints on a car body replace the welds etc. and thus facilitate the recycle process. Hot-melt adhesives such as polyamides and Micropearl F30 should be mentioned here as stimuli-responsive adhesion promoters. React e.g. Sibler particles aggregated at the substrate surface with a complexing agent, e.g. Saline or sulfur-containing compounds, the surface modification system according to the invention itself can act as a stimuli-responsive adhesion mediators. In this way, the adhesive strength and thus the adhesion can be influenced.

In a further embodiment, the surface modification system of the invention is used to coat semiconductor surfaces (such as silicon wafer surfaces). For example, an increase in the efficiency of the solar cells can be achieved by the plasmon resonance of immobilized metal nanoparticles.

In a further embodiment, the surface modification system according to the invention is used for the production of circuits. Defined structures with a small space requirement can be realized by the use of (laser) optical methods, electron bombardment, ion bombardment or other etching methods.

In a further embodiment, the surface modification system according to the invention is used in dental or orthopedic applications. By a coating of e.g. Titanium components, thus an improved compatibility with the body tissue can be achieved.

In a further embodiment, the surface modification system according to the invention is used in electrical applications. Strongly adherent, elastic, homogeneous and defect-free insulation can be achieved, for example, by coating with paper fibers. Similar applications are conceivable for capacitors or transformers.

In a further embodiment, the surface modification system according to the invention is used for the homogeneous coating of metal foam. Bioresorbable components made of ferrous metal foams are very interesting for osteosurgical application. The integration of these components is enhanced by pre-immobilized apatites. However, due to different material properties between metal and mineral, such systems are mechanically and thermally unstable. The surface modification system of the present invention can stabilize such systems by compensating for any shear forces due to the combination of surface roughness and polymer chain mobility.

In a further embodiment the surface modification system according to the invention is used for the production of protective coatings on e.g. Used steels. By sintering immobilized powder filled pastes, e.g. Aluminide protective coatings which reduce hot air corrosion resistance in e.g. Increase automotive catalytic converters.

In a further embodiment, the inventive Surface modification system with water glass, such as in DE4040153A1 described, coated. As a result, water- and fire-stable surfaces can be produced, which are break-stabilized by the stress-absorbing effect of the particle-protecting polymers.

In a further embodiment, the surface modification system according to the invention is used to display analytical surfaces. Possible applications are in screening analysis such as e.g. To find SPR spectroscopy. The immobilized by means of the clamping mechanism polymers completely novel surface functionalities can be displayed, which corresponds to a wider range of applications.

In a further embodiment, the surface modification system according to the invention for the diamond coating is used and so abrasion-stable, corrosion-resistant layers combined with lubricious surfaces.

LIST OF REFERENCE NUMBERS

100

metallic substrate

101

Reaction between polymer-protected particles and substrate surface

102

Derivatization of surface modification to generate ionic charges

103

Coating with target molecules

104

Colloidal polymer-stabilized metal particles

105

Metal layer with immobilized polymer chains (clamping complexes)

106

ionically charged adhesive layer

107

functional coating

200

metallic substrate

201

Reaction between polymer protected landed particles and substrate surface

202

Coating with target molecules

203

ionically charged, colloidal polymer-stabilized metal particles

204

Metal layer with immobilized polymer chains (clamping complexes)

205

functional coating

Claims (13)

1. A method for coating a surface of a substrate having a metallic nature using particles, comprising the following steps:

   - dispersing the particles in a solvent, wherein the particles employed are metal particles/metal alloy particles/metal oxide particles and have dimensions in the micron/submicron or nanometre range,

   - stabilizing the colloidal particles with a polymer, wherein the polymer is a dispersion-stabilizing biocompatible polymer or hydrogel-forming polymer,

   - wetting the metallic surface to be coated with the stabilized particle solution, whereupon the polymer chains become fixed in the interstices between the metallic surface and the particle by means of a clamping mechanism,

   - forming a stable particle layer on the substrate surface by collapse and aggregation of the colloidal system,

   - removing the non-bound particles after completing the coating procedure by washing with a solvent,

   - generating ionic charges on the coated metal surface, and

   - finally, drying the coated metal surface.
2. The method as claimed in claim 1, characterized in that a stabilization of the adhesion promoting layer is accomplished by initiating cross-linking steps.
3. The method as claimed in claims 1 and 2, characterized in that the metal particles/metal alloy particles/metal oxide particles employed are composed of one or more elements selected from groups 3 to 16 and the lanthanides of the periodic table of the elements, their isotopes, salts and also mixtures and alloys thereof.
4. The method as claimed in one of the preceding claims, characterized in that the particles are at least partially coated with one or more colloid-stabilizing polymers.
5. The method as claimed in one of the preceding claims, characterized in that different deposition strategies such as electrophoretic deposition and chemical in situ deposition are used, in combination and separately.
6. The method as claimed in one of the preceding claims, characterized in that the particles exhibit a functionalization due to the colloid-stabilizing polymers employed.
7. The method as claimed in one of the preceding claims, characterized in that dispersions are used which are composed of polymer-stabilizing particles and/or one or more oligomeric/polymeric components and/or radical initiators and/or cross-linking agents and/or complex-forming agents and/or surfactants which allow system-stabilizing cross-linking reactions to occur.
8. The method as claimed in one of the preceding claims, characterized in that further cross-linking reactions are carried out in order to provide the modified surfaces with additional stabilization.
9. The method as claimed in one of the preceding claims, characterized in that ionic charges are produced on the dispersion-stabilized polymer by means of a reaction step wherein the ionic charge of the modified surface is changed by changing the pH.
10. The method as claimed in one of the preceding claims, characterized in that after coating the metal surface with the functionalizing particles, loading with target molecules is carried out, wherein the interaction between the adhesion promoting layer and the target molecule is based on stereocomplex-like electrostatic effects or hydrogen bonds.
11. The method as claimed in one of the preceding claims, characterized in that a combination of collapsed particles and interpenetrating matrices is used, by which means the susceptibility of the subsequently applied coating with target molecules to stress is reduced.
12. A coated substrate surface with a metallic nature produced in accordance with a method as claimed in claims 1 to 11.
13. Use of a coated metallic surface as claimed in claim 12 to immobilize functional coatings such as non-reflective, anti-fouling, lubricating; synthetic/natural target molecules, hydrogel polymers; pharmaceuticals; peptides; antimicrobial agents; lipids; polysaccharides; biologically active molecules such as antibodies, nucleotides, enzymes, signal peptides, fluorescent/phosphorescent colorants, minerals, nanoparticles; clay minerals or activated carbon for example for water treatment; clathrates; cyclodextrin and other supermolecules, such as for detoxification or endotoxin removal; isolation surfaces, photoelectrically active surfaces, or biomimetic surfaces.

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