WO2016019568A1

WO2016019568A1 - 3d organic-inorganic hybridized compositions and methods

Info

Publication number: WO2016019568A1
Application number: PCT/CN2014/083970
Authority: WO
Inventors: Anna Liu; Marilyn Wang
Original assignee: Honeywell International Inc.
Priority date: 2014-08-08
Filing date: 2014-08-08
Publication date: 2016-02-11

Abstract

A coating including at least one of a cationically polymerizable compound, including at least one epoxy group, and a radically polymerizable compound, including at least one acrylate group. The coating further includes an inorganic nano-wire and at least one surfactant. Methods for forming a coated substrate can include preparing inorganic nano-fibers, dispersion the nano-fibers in a solution to form a suspension. In an example, the suspension can be mixed with ta matrix solution to form a coating. The coating can then be applying to a substrate and cured to form a coated substrate.

Description

3D ORGANIC-INORGANIC HYBRIDIZED COMPOSITIONS AND METHODS

TECHNICAL FIELD

[0001] The present subject matter relates generally to 3D organic-inorganic hybridized compositions, such as anti-fog coating compositions and methods for forming coated transparent polymeric materials, andcoated transparent polymeric materials. More particularly,the present application relates to epoxy, acrylate, and epoxy-acrylate coating compositions including inorganic nano-wire that impartlong-lasting anti-fog performance for transparent polymeric materials, methods forforming coated transparent polymeric materials using such coating compositions, andcoated transparent polymeric materials with long-lasting anti-fog performance.

BACKGROUND

[0085] Transparent polymeric materials are used for a variety of products through whichlight is transmitted for viewing an image. The transparent polymeric material typicallyhas a first surface and a second surface. One surface can be curved relative to the other tochange the direction of light to the eye, such as in an ophthalmic lens of eyeglasses, or alternatively, the surfaces can be parallel, such as in a television screen or a face shield ofa protective helmet. Common lens forming materials include CR-39 (diethyleneglycolbisallyl carbonate), bisphenol A polycarbonate (PC), and poly(methylmethacrylate)(PMMA). These lens forming materials are lighter and more shatter resistant thantraditional glass and offer excellent transparency and low haze. Despite the above notedbenefits, some serious drawbacks to transparent polymeric materials include theirsusceptibility to fogging, scratching and/or abrasion.

[0086] Transparent polymeric materials become fogged when tiny water

dropletscondense on the surface and cause light to scatter, rendering the surface

translucent.Fogging typically occurs when a cold surface suddenly comes in contact with warm, moistair. In some cases, fogging can be a dangerous condition, for example, when the foggedmaterial is an ophthalmic lens affecting a user's vision. Additionally,

transparentpolymeric materials are much softer than glass and can be easily scratched under normalactions such as cleaning, wiping off dust, and normal handling while in use. Over time,scratches and abrasions on the surface can also obscure the user's vision. [0087] Consequently, such transparent polymeric surfaces are often treated with one ormore coatings to provide anti-fog performance, and scratch and/or abrasion resistance.Lens coatings can be applied in different ways, such as, for example, using a dip coatingprocess or a spin coating process.

[0088] In this regard, much research has been devoted to providing coatings

fortransparent polymeric materials to improve their anti-fog performance, and scratch and/orabrasion resistance. State of the art anti-fog (AF) technologies typically include twoapproaches to maintain surface transparency after moisture condensation. One approach isto treat a surface by applying a completely hydrophilic coating to absorb all of the watermolecules in the coating's interior; or alternatively, another approach is to embedhydrophilic surfactants within an otherwise hydrophobic coating to reduce the watercontact angle and to spread condensed moisture from scattered and scattering droplets intoa flat film (sheeting), thereby minimizing the transmission loss. Each of these approacheshas its own limitations and shortcomings.

[0089] Current water absorbing AF coating systems are normally made from

crosslinkedor non-crosslinked hydrophilic polymers (e.g. hydrophilic acrylic polymers or copolymers,crosslonked polyvinyl alcohol, and hydrophilic polyurethane). Water molecules can easilydiffuse into this hydrophilic coating layer, thus preventing moisture condensation on thesubstrate surface. However, the absorption capacity is limited by thethickness of the coating. In addition, the slow kinetics of absorption by diffusion may notbe sufficient to prevent instant fogging in a high humidity environment. If the absorptioncapacity is saturated ether kinetically or thermodynamically, the coating loses its AF effect. The water entrapped in the coating will also swell the coating layer and make thecoating more susceptible to mechanical and chemical damage. Adhesion failure, or evendelamination, often occurs when used in a high humidity environment. These mechanicalfailures are caused by water adsorption into the coating and the subsequent swelling of thecoating resin. Another common strategy is designed to reduce water absorption byspreading condensed water droplets into a surface thin film via hydrophilic surfactants anda hydrophobic coating that migrate to the top surface during processing to produce thecontact angle, and spread a water droplet(s) into a flat film.

[0090] Most anti-fog coatings on the market include incorporating mobile surfactantsinto a coating matrix. When moisture condensation occurs, the surfactants will eithermigrate to or orient towards the top surface to reduce the water-solid interfacial tensionand the contact angle. As the surfactants are not chemically bonded to the coatingstructure, the surfactants will be washed off the surface either by repeated use or cleaning,leading to a fade-away AF effect. Therefore, they are suitable for providing only atemporary, i.e., not durable, AF effect. In addition, the surface is prone to damage andstaining. Moreover, the plasticizing effect of the surfactant on the coating surface oftenmakes the coating more vulnerable to abrasion and contamination.

[0091] Chemistries and coating processes for these coatings range from thermally curedcoatings to ultraviolet (UV) cured coatings. Unfortunately, many of these

conventionalcoatings have several drawbacks. For example, current anti-fog coatings are generally notlong-lasting and often lose effectiveness after only a few lens cleanings. Moreover, many of these coatings require the use of a solvent and/or a primer that is undesirably high in volatile organic compound (VOC) content. Furthermore, while thermally cured coatings may provide good scratchresistance, they also require long cure times and high energy consumption for solventevaporation. Additionally, while UV cured coatings provide fast cure, energy savings, andhigh throughput production, their scratch resistance is generally poorer than withthermally cured coatings.

SUMMARY

[0009] A coating can include at least one of a cationically polymerizable compound, including at least one epoxy group, and a radically polymerizable compound, including at least one acrylate group. In an example, the coating includes an inorganic nano-wire and at least one surfactant.

[0010] A method for forming a coated substrate includes preparing inorganic nano-fibers having an average diameter of about 5 nanometers to about 20 nanometers and an average length of about 5 micrometers to about 15 micrometers. The method further includes dispersing, by sonication, the prepared inorganic nano-fibers in a solution to for a suspension and mixing the suspension with a matrix solution to form a coating. The matrix solution includingat least one of a cationically polymerizable compound, including at least one epoxy group, and a radically polymerizable compound, including at least one acrylate group. The coating further includes an inorganic nano-wire and at least one surfactant. The method can include applying at least a portion of the coating to a substrate and curing the applied coating to forma coated substrate.

DETAILED DESCRIPTION OF THE DRAWINGS

[0011] The embodiments of the present application will be described, by way of example only, by reference to FIGS. 1 and 2 of the accompanying drawings in which:

[0012] FIG. 1 illustrates a cross-section of a substrate having a coating including inorganic nano- wires; and

[0013] FIG. 2 illustrates an example of comparative Taber testing of Examples 1.1 and 1.2

DETAILED DESCRD7TION

[0014] The following Detailed Description is merely exemplary in nature and is notintended to limit the subject matter or the application and uses of the subject matter. Furthermore, there is no intention to be bound by any theory presented in the preceding background orthe following detailed description.

[0015] In an embodiment, an improved coating system for transparentpolymeric materials, such as ophthalmic lenses, provides improved characteristics in theform of anti-fog performance and scratch or abrasion resistance, while also providingimproved manufacturability and rapid curing as compared to prior art coating systems. Generally, the coating system described herein is a composite coating thathybridizes at least one of epoxy and acrylate with an inorganic nano- wire material into a single coating system that canhave improved abrasion resistance, as compared to previous approaches. In an example, the coating system exhibits themechanical properties imparted by epoxies creating a highly abrasion resistant coating while also including the advantageous properties of radiation cured coatings imparted by acrylates in the form of rapid processing and curing as well as a superior vehicle for retaining surfactants. For example, coating compositions described herein can include reduced surfactant diffusion rates and flexible acrylate-epoxy and petrous nano-wire construction, which provides improved abrasion resistance, greater impact resistance, and flexibility as compared to previous approaches.

[0016] Accordingly, it is some embodiments may provide one or more features or benefits such as compositions that impart long-lasting anti-fog performance for transparent polymeric materials, methods for formingcoated transparent polymeric materials using such coating compositions, and coatedtransparent polymeric materials with long-lasting anti-fog performance. Moreover, it issome embodiments may provide coating compositions that impart improved properties such as scratchor abrasion resistance, rapid curing, relatively low solvent/VOC content,reduced surfactant diffusions rates, or greater impact resistance, methods for forming coated transparent polymeric materials using such coatingcompositions, and coated transparent polymeric materials that include such coating compositions. Furthermore, other features and characteristics of the presentembodiments will become apparent from the subsequent detailed description and the appendedclaims, taken in conjunction with the accompanying drawings and this background.

[0017] Various optical terms are used to describe thetransparent polymeric material, e.g., lens, ophthalmic lens, optical filter, and the like. Tofacilitate the understanding of the coatings described herein, some terms are initially defined as follows:

[0018] Lens: an ophthalmic lens that provides refractive correction or a lens thatprovides no refractive correction also known as a "piano lens".

[0019] Visible light spectrum: energy emissions having a wavelength ofbetweenapproximately 400 nm and 780 nm.

[0020] Infrared and near infrared: energy emissions having a wavelength on the order ofbetween approximately 750 nm and 3000 nm.

[0021] FIG. 1 illustrates a cross-section 1 of a substrate 2 including a coating 4 having inorganic nano-wires 6, as described herein. In an example, a coating can include at least one of a cationically polymerizable compound including at least one epoxy, and a radically

polymerizable compound, including at least one acrylate group. Further, the coating can include at least one surfactant, such as a non-ionic surfactant or an ionic surfactant. In an example, the coating includes at least one inorganic nano-wire. Additional examples include initiators or additives.

[0022] In an example, the coating is a suspension that includes organicpolymeric constituents and, optionally, solvents. A polymeric constituent may be a monomer or a polymer in solvent. For example, the coating may includemonomers that polymerize upon curing. Alternatively or in addition, the coating may include polymer material in a solvent. The particulate filler generally forms adispersed phase within the coating. [0023] The coating may include one or more reaction constituents or polymerconstituents for the preparation of a polymer. A polymer constituent may includemonomeric molecules, polymeric molecules or a combination thereof. The coating may further comprise components selected from the group consisting of solvents,plasticizers, chain transfer agents, catalysts, stabilizers, surfactants, curing agents, reactionmediators and agents for influencing the fluidity of the dispersion.

[0024] The polymer constituents can form thermoplastics or thermosets. By way ofexample, the polymer constituents may include monomers and resins for the formation ofpolyurethane, polyurea, polymerized epoxy, polyester, polyimide, polysiloxanes(silicones), polymerized alkyd, styrene-butadiene rubber, acrylonitrile-butadiene rubber,polybutadiene, or, in general, reactive resins for the production of thermoset polymers. Another example includes an acrylate or a methacrylate polymer constituent. Theprecursor polymer constituents are typically curable organic material (i.e., a polymermonomer or material capable of polymerizing or crosslinking upon exposure to heat orother sources of energy, such as electron beam, ultraviolet light, visible light, etc., or withtime upon the addition of a chemical catalyst, moisture, or other agent which cause thepolymer to cure or polymerize). A precursor polymer constituent example includes areactive constituent for the formation of an amino polymer or an aminoplast polymer, suchas alkylated urea-formaldehyde polymer, melamine-formaldehyde polymer, and

alkylatedbenzoguanamine-formaldehyde polymer; acrylate polymer including acrylate andmethacrylate polymer, alkyl acrylate, acrylated epoxy, acrylated urethane, acrylatedpolyester, acrylated polyether, vinyl ether, acrylated oil, or acrylated silicone; alkydpolymer such as urethane alkyd polymer; polyester polymer; reactive urethane polymer;phenolic polymer such as resole and novolac polymer; phenolic/latex polymer; epoxypolymer such as bisphenol epoxy polymer; isocyanate; isocyanurate; polysiloxanepolymer including alkylalkoxysilane polymer; or reactive vinyl polymer. The coating of the coating formulation may include a monomer, an oligomer, a polymer, or acombination thereof. In a particular embodiment, the coating of the coating formulation includes monomers of at least two types of polymers that when cured maycrosslink. For example, the coating may include epoxy constituents and acrylicconstituents that when cured form an epoxy/acrylic polymer.

[0025] In an embodiment, the polymer reaction components includeanionically and cationically polymerizable precursors. For example, the coating may include at least one cationically curable component, e.g., at least one cyclic ethercomponent, cyclic lactone component, cyclic acetal component, cyclic thioethercomponent, spiroorthoester component, epoxy-functional component, or oxetane-functionalcomponent. Typically, the coating includes at least one componentselected from the group consisting of epoxy-functional components and oxetane-functionalcomponents. The coating may include, relative to the total weight of thecomposite coating formulation, at least aboutlO wt.% of cationically curable components,for example, at least about 20 wt. %, typically at least about 40 wt. %, or at least about 50wt. %. Generally, the coating includes, relative to the total weight of the composite coating formulation, not greater than about 95 wt. %of cationically curable components,for example, not greater than about 90 wt. %, not greater than about 80 wt. %, or notgreater than about 70 wt. %.

[0026] In an optional embodiment, the coating may include at least one epoxy- functionalcomponent, e.g., an aromatic-epoxy-functional component ("aromatic epoxy ormore preferably an aliphatic epoxy-functional component ("aliphatic epoxy"). Epoxy- functionalcomponents are components comprising one or more epoxy groups, i.e., one ormore three-member ring structures (oxiranes).

[0027] Aromatic epoxy components include one or more epoxy groups and one or

morearomatic rings. The coating may include one or more aromatic epoxy components. An example of an aromatic epoxy component includes an aromatic epoxy derived from apolyphenol, e.g., from bisphenols, such as bisphenol A (4,4'-isopropylidenediphenol),bisphenol F (bis[4- hydroxyphenyl]methane), bisphenol S (4,4'- sulfonyldiphenol), 4,4'- cyclohexylidenebisphenol,4,4'-biphenol, or 4,4'-(9-fluorenylidene)diphenol. Thebisphenol may be alkoxylated (e.g., ethoxylated or propoxylated) or halogenated (e.g.,brominated). Examples ofbisphenol epoxies include bisphenoldiglycidyl ethers, such asdiglycidyl ether oiBisphenol A or Bisphenol F.

[0028] A further example of an aromatic epoxy includes triphenylolmethanetriglycidylether, 1,1 , l-tris(p-hydroxyphenyl)ethane triglycidyl ether, or an aromatic epoxy derivedfrom a monophenol, e.g., from resorcinol (for example, resorcindiglycidyl ether) orhydroquinone (for example, hydroquinone diglycidyl ether). Another example isnonylphenylglycidyl ether.

[0029] In addition, an example of an aromatic epoxy includes epoxy novolac, for example, phenol epoxy novolac and cresol epoxy novolac. A commercial example of acresol epoxy novolac includes, for example, EPICLON N-660, N-665, N-667, N-670, N-673, N-680, N-690, orN-695, manufactured by Dainippon Ink and Chemicals, Inc. Anexample of a phenol epoxy novolac includes, for example, EPICLON N-740, N-770, N-775, or N-865, manufactured by Dainippon Ink and Chemicals Inc.

[0030] In one embodiment, the coating may contain, relative to the total weightof the composite coating formulation, at least 10 wt.% of one or more aromatic epoxies.

[0031] Aliphatic epoxy components have one or more epoxy groups and are free ofaromatic rings. The coating may include one or more aliphatic epoxies. Anexample of an aliphatic epoxy includes glycidyl ether ofC2-C30 alkyl; 1,2 epoxy ofC3-C30 alkyl; mono or multi glycidyl ether of an aliphatic alcohol or polyol such as 1 ,4-butanediol, neopentyl glycol, cyclohexane dimethanol, dibromoneopentyl glycol,trimethylol propane, polytetramethylene oxide, polyethylene oxide, polypropylene oxide,glycerol, and alkoxylated aliphatic alcohols; or polyols.

[0032] In one embodiment, the aliphatic epoxy includes one or more cycloaliphatic ringstructures. For example, the aliphatic epoxy may have one or more cyclohexene

oxidestructures, for example, two cyclohexene oxide structures. An example of an aliphaticepoxy comprising a ring structure includes hydrogenated bisphenol A diglycidyl ether,hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether,bis(4- hydroxycyclohexyl)methane diglycidyl ether, 2,2-bis(4-hydroxycyclohexyl)propanediglycidyl ether, 3,4-epoxycyclohexylmethyl -3,4-epoxycyclohexanecarboxylate, 3,4-5epoxy-6- methylcy clohexy lmethy 1-3 ,4-epoxy-6-methylcyclohexanecarboxylate, di(3 ,4- epoxy cy clohexy lmethy l)hexanedioate, di(3 ,4-epoxy-6-methylcy clohexy 1 methyl) hexanedioate, ethylenebis(3,4-epoxycyclohexanecarboxylate), ethanedioldi(3,4-epoxycyclohexylmethyl)ether, or 2-(3,4-epoxycy clohexy 1 -5, 5-spiro-3,4-epoxy)cyclohexane-l ,3-dioxane.

[0033] In an embodiment, the coating includes, relative to the total weight of thecomposite coating formulation, at least about 5 wt. % of one or more aliphatic epoxies, forexample, at least about 10 wt.% or at least about 20 wt.% of the aliphatic epoxy. Generally, the coating includes, relative to the total weight of the composite coating formulation, not greater than about 70 wt.% of the aliphatic epoxy, for example, notgr eater than about 50 wt. %, for example not greater than about 40 wt. %.

[0034] Typically, the coating includes one or more mono or poly glycidylethersof aliphatic alcohols, aliphatic polyols, polyesterpolyols or polyetherpolyols. An exampleof such a component includes 1 ,4-butanedioldiglycidylether, glycidylether ofpolyoxy ethylene or polyoxypropylene glycol or triol of molecular weight from about 200to about 10,000;

glycidylether ofpolytetramethylene glycol orpoly(oxyethyleneoxybutylene)random or block copolymers. An example of commercially availableglycidylether includes a

polyfunctionalglycidylether, such as Heloxy 48, Heloxy 67,Heloxy 68, Heloxy 107, and Grilonit F713; or monofunctionalglycidylethers, such asHeloxy 71 , Heloxy 505, Heloxy 7, Heloxy 8, and Heloxy 61 (sold by ResolutionPerformances, www.resins.com).

[0035] The coating may contain about 3 wt.% to about 40 wt. %, more typicallyabout 5 wt. %to about 20 wt. % of mono or poly glycidyl ethers of an aliphatic alcohol,aliphatic polyol, polyesterpolyol or polyetherpolyol.

[0036] The coating may include one or more oxetane-functional components("oxetanes"). Oxetanes are components having one or more oxetane groups, i.e., one ormore four-member ring structures including one oxygen and three carbon members.

[0037] In addition to or instead of one or more cationically curable components, the coating may include one or more free radical curable components, e.g., one or morefree radical polymerizable components having one or more ethylenically unsaturatedgroups, such as (meth)acrylate (i.e., acrylate or methacrylate) functional components.

[0038] An example of a monofunctionalethylenically unsaturated component

includesacrylamide, Ν,Ν-dimethylacrylamide, (meth)acryloylmorpholine, 7-amino-3,7- dimethyloctyl (meth)acrylate, isobutoxymethyl(meth)acrylamide, isobornyloxy ethyl

(meth)acrylate, isobornyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, ethyldiethyleneglycol (meth)acrylate, t-octyl(meth)acrylamide, diacetone

(meth)acrylamide, dimethy laminoethy l(meth)acry late, diethy laminoethy l(meth)acrylate, laury 1 (meth)acrylate, dicyclopentadiene (meth)acrylate,

dicyclopentenyloxyethyl(meth)acrylate,dicyclopentenyl(meth)acrylate, N,N-dimethyl(meth) acrylamidetetrachlorophenyl(meth)acrylate, 2-tetrachlorophenoxy ethyl

(meth)acrylate,tetrahydrofurfuryl(meth)acrylate, tetrabromophenyl(meth)acrylate, 2- tetrabromophenoxyethyl (meth)acrylate, 2- trichlorophenoxyethyl(meth)acrylate,tribromophenyl(meth)acrylate, 2- tribromophenoxyethyl(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2- hydroxypropyl(meth)acrylate, vinylcaprolactam, N- vinylpyrrolidone,phenoxyethyl(meth)acrylate, butoxyethyl(meth)acrylate, pentachlorophenyl(meth)acrylate, pentabromophenyl(meth)acrylate, polyethylene glycolmono(meth)acrylate, polypropylene glycol mono(meth)acrylate,

bornyl(meth)acrylate,methyltriethylenediglycol (meth)acrylate, or a combination thereof.

[0039] An examples of the polyfunctionalethylenically unsaturated component

includesethylene glycol di(meth)acrylate, dicyclopentenyl di(meth)acrylate, triethylene glycoldiacrylate, tetraethylene glycol di(meth)acrylate,

tricyclodecanediyldimethylenedi(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylatedtrimethylolpropanetri(meth)acrylate, propoxylatedtrimethylolpropane

tri(meth)acrylate, tripropylene glycoldi(meth)acrylate, neopentyl glycol di(meth)acrylate, both- terminal (meth)acrylic acidadduct ofbisphenol A diglycidyl ether, 1 ,4-butanediol

di(meth)acrylate, l,6-hexanedioldi(meth)acrylate, polyethylene glycol di(meth)acrylate, (meth)acrylate-functionalpentaerythritol derivatives (e.g., pentaerythritol tri(meth)acrylate, pentaerythritoltetra(meth)acrylate, d ipentaerythritolhexa(meth)acrylate,

dipentaerythritolpenta(meth)acrylate, or dipentaerythritol tetra(meth)acrylate),

ditrimethylolpropanetetra(meth)acrylate, ethoxylatedbisphenol A di(meth)acrylate,

propoxylatedbisphenol Adi(meth)acrylate, ethoxylated hydrogenated bisphenol A

di(meth)acrylate, propoxylated-modifiedhydrogenated bisphenol A di(meth)acrylate, ethoxylatedbisphenol Fdi(meth)acrylate, or a combination thereof.

[0040] In one embodiment, the coating formulation comprises one or more componentshaving at least 3 (meth)acrylate groups, for example, 3 to 6 (meth)acrylate groups or 5 to

6(meth)acrylate groups.

[0041] In particular embodiments, the coating includes, relative to the totalweight of the composite coating formulation, at least about 3 wt. % of one or more freeradical polymerizable components, for example, at least about 5 wt. %, for example atleast about 9 wt. %. Generally, the coating includes not greater than about 50 wt.% of free radical polymerizable components, for example, not greater than about 3 5 wt. %,for example, not greater than about 25 wt. %, for example not greater than about 20 wt. %,for example not greater than about 15 wt. %.

[0042] Generally, the polymer reaction constituents or precursors have on average atleast two functional groups, such as on average at least 2.5, for example at least 3.0functional groups. For example, an epoxy precursor may have 2 or more epoxy-functionalgroups. In another example, an acrylic precursor may have two or more methacrylatefunctional groups. [0043] It has been found that a coating including a component having apoly ether backbone shows excellent mechanical properties after cure of the composite coating formulation. An example of a compound having a poly ether backbone includespolytetramethylenediol, a glycidylether ofpolytetramethylenediol, an acrylate ofpolytetramethylenediol, a

polytetramethylenediol containing one or more polycarbonategroups, or a combination thereof. In an embodiment, the coating includes between5 wt. % and 20 wt. % of a compound having a poly ether backbone.

[0044] The coating may also include catalysts and initiators. For example, acationic initiator may catalyze reactions between cationic polymerizable constituents. Aradical initiator may activate free-radical polymerization of radiacally polymerizableconstituents. The initiator may be activated by thermal energy or actinic radiation. Forexample, an initiator may include a cationic photoinitiator that catalyzes cationicpolymerization reactions when exposed to actinic radiation. In another example, theinitiator may include a radical photoinitiator that initiates free-radical polymerizationreactions when exposed to actinic radiation. Actinic radiation includes particulate ornon-particulateradiation and is intended to include electron beam radiation andelectromagnetic radiation. In a particular embodiment, electromagnetic radiation includesradiation having at least one wavelength in the range of about 100 nm to about 700 nmand, in particular, wavelengths in the ultraviolet range of the electromagnetic spectrum.

[0045] Generally, cationic photoinitiators are materials that form active species that, ifexposed to actinic radiation, are capable of at least partially polymerizing epoxides oroxetanes. For example, a cationic photoinitiator may, upon exposure to actinic radiation,form cations that can initiate the reactions of cationically polymerizable components, suchas epoxies or oxetanes.

[0046] An example of a cationic photoinitiator includes, for example, onium salt withanions of weak nucleophilicity. An example includes a halonium salt, an iodosyl salt or asulfonium salt, a sulfoxonium salt, or a diazonium salt. Other examples of cationicphotoinitiators include metallocene salt.

[0047] The coating may optionally include photoinitiators useful for photocuringfree-radically polyfunctional acrylates. An example of a free radical photoinitiatorincludes benzophenone (e.g., benzophenone, alkyl-substituted benzophenone, or alkoxy-substitutedbenzophenone); benzoin (e.g., benzoin, benzoin ethers, such as benzoin methylether, benzoin ethyl ether, and benzoin isopropyl ether, benzoin phenyl ether, and benzoinacetate); acetophenone, such as acetophenone, 2,2-dimethoxyacetophenone, 4-(phenylthio)acetophenone, and 1 , 1 -dichloroacetophenone;

benzilketal, such as benzyl dimethyl ketal, and benzil diethyl ketal; anthraquinone, such as 2- methylanthraquinone, 2-ethylanthraquinone, 2-tertbutylanthraquinone, 1-chloroanthraquinone, and 2-amylanthraquinone; triphenylphosphine; benzoylphosphine oxides, such as, for example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; thioxanthone or xanthone; acridinederivative; phenazene derivative; quinoxaline derivative; 1 -phenyl- l,2-propanedione-2-0-benzoyloxime; 1- aminophenyl ketone or 1 -hydroxyphenyl ketone, such as 1 -hydroxy cyclohexyl phenyl ketone, phenyl(l-hydroxyisopropyl)ketone and 4-isopropylphenyl(l -hydroxy isopropyl)ketone; or a triazine compound, for example, 4"'-methyl thiophenyl-l-di(trichloromethyl)-3,5-S-triazine, S- triazine-2-(stilbene)-4,6-bistrichloromethyl, or paramethoxystyryltriazine.

[0048] An example of a photoinitiator includes benzoin or its derivative such as a- methylbenzoin;U-phenylbenzoin; a-allylbenzoin; a-benzylbenzoin; benzoin ethers suchas benzil dimethyl ketal (available, for example, under the trade designation "IRGACURE651 " from Ciba Specialty Chemicals), benzoin methyl ether, benzoin ethyl ether, benzoinn-butyl ether;

acetophenone or its derivative, such as 2-hydroxy-2-methyl-l -phenyl- 1-propanone (available, for example, under the trade designation "DAROCUR 1173" fromCiba Specialty Chemicals) and 1- hydroxycyclohexyl phenyl ketone (available, forexample, under the trade designation

"IRGACURE 184" from Ciba Specialty Chemicals); 2-methyl-l-[4-(methylthio) phenyl]-2-(4- morpholinyl)- -1-propanone (available, forexample, under the trade designation "IRGACURE 907" from Ciba Specialty Chemicals);2-benzyl-2-(dimethlamino)-l [4-(4-morpholinyl) phenyl]- 1-butanone (available, forexample, under the trade designation "IRGACURE 369" from Ciba Specialty Chemicals);or a blend thereof.

[0049] Another useful photoinitiator includes pivaloin ethyl ether, anisoin ethyl

ether; anthraquinones, such as anthraquinone, 2-ethylanthraquinone, 1-chloroanthraquinone, 1,4- dimethylanthraquinone, 1 -methoxyanthraquinone, benzanthraquinonehalomethyltriazines,and the like; benzophenone or its derivative; iodonium salt or sulfonium salt as describedhereinabove; a titanium complex such as bis(5-2,4-cyclopentadienyl)bis[2,-6-difluoro-3-(lH- pyrrolyl)phenyl)titanium (commercially available under the trade designation" CGI 784DC", also from Ciba Specialty Chemicals); a halomethylnitrobenzene such as 4-bromomethylnitrobenzene and the like; or mono- or bis-acylphosphine (available, forexample, from Ciba Specialty

Chemicals under the trade designations "IRGACURE1700", "IRGACURE 1800", "IRGACURE 1850", and "DAROCUR 4265"). A suitablephotoinitiator may include a blend of the above mentioned species, such as a-hydroxyketone/acrylphosphin oxide blend (available, for example, under the trade designationlRGACURE 2022 from Ciba Specialty Chemicals).

[0050] A further suitable free radical photoinitiator includes an ionic dye-counter

ioncompound, which is capable of absorbing actinic rays and producing free radicals, whichcan initiate the polymerization of the acrylates.

[0051] A photoinitiator can be present in an amount not greater than about 20 wt. %, forexample, not greater than about 10 wt. %, and typically not greater than about 5 wt. %,based on the total weight of the coating formulation. For example, a photoinitiator may bepresent in an amount of 0.1 wt.% to 20.0 wt. %, such as 0.1 wt.% to 5.0 wt. %, or mosttypically 0.1 wt. %to 2.0 wt. %, based on the total weight of the coating formulation,although amounts outside of these ranges may also be useful. In one example, thephotoinitiator is present in an amount at least about 0.1 wt. %, such as at least about l .Owt. %, for example in an amount 1.0 wt.% to 10.0 wt. %.

[0052] Optionally, a thermal curative may be included in the coating. Such athermal curative is generally thermally stable at temperatures at which mixing of thecomponents takes place. Example thermal curatives for epoxy resins and acrylates arewell known in the art. A thermal curative may be present in a coating precursor in anyeffective amount. Such amounts are typically in the range of about 0.01 wt.% to about5.0 wt. %, desirably in the range from about 0.025 wt. %to about 2.0 wt. %by weight,based upon the weight of the coating formulation, although amounts outside of these rangesmay also be useful.

[0053] The coating may also include other components such as solvents,plasticizers, crosslinkers, chain transfer agents, stabilizers, surfactants, curing agents,reaction mediators and agents for influencing the fluidity of the dispersion. For example,the coating can also include one or more chain transfer agents selected from thegroup consisting of polyol, polyamine, linear or branched polyglycol ether, polyester andpolylactone.

[0054] In another example, the coating may include additional components, suchas a hydroxy- functional or an amine functional component and additive. Generally, theparticular hydroxy - functional component is absent curable groups (such as, for example,acrylate-, epoxy-, or oxetane groups) and is not selected from the group consisting ofphotoinitiators. [0055] The coating may include one or more hydroxy-functional components. Hydroxy- functional components may be helpful in further tailoring mechanical propertiesof the coating formulation upon cure. Anhydroxy-functional component includes monol (ahydroxy-functional component comprising one hydroxy group) or polyol (a hydroxyfunctionalcomponent comprising more than one hydroxy group).

[0056] A representative example of a hydroxy-functional component includes analkanol, a monoalkyl ether of polyoxyalkyleneglycol, a monoalkyl ether ofalkyleneglycol,alkylene and arylalkylene glycol, such as 1 ,2,4-butanetriol, 1 ,2,6-hexanetriol, 1 ,2,3-heptanetriol, 2,6-dimethyl- 1,2,6-hexanetriol, (2R,3R)-(-)-2-benzyloxy-l ,3,4-butanetriol,l ,2,3-hexanetriol, 1,2,3-butanetriol, 3-methyl-l ,3,5-pentanetriol, l ,2,3-cyclohexanetriol,l,3,5-cyclohexanetriol, 3,7,11,15- tetramethyl-l,2,3-hexadecanetriol, 2-hydroxymethyltetrahydropyran-3,4,5-triol, 2,2,4,4- tetramethyl-l,3-cyclobutanediol, 1 ,3-cyclopentanediol, trans- 1 ,2-cyclooctanediol, 1,16- hexadecanediol, 3,6-dithia-l,8-octanediol, 2-butyne-l,4-diol, 1,2- or 1,3 -propanediol, 1 ,2- or 1 ,4- butanediol, 1 ,5-pentanediol, 1 ,6-hexanediol, 1,7-heptanediol, 1 ,8-octanediol, 1,9-nonanediol, 1- phenyl-l ,2-ethanediol, 1 ,2-cyclohexanediol, 1,5-decalindiol, 2,5-dimethyl-3-hexyne-2,5- diol,2,2,4-trimethylpentane-l,3-diol, neopentylglycol, 2-ethyl -l,3-hexanediol, 2,7-dimethy 1-3,5- octadiyne-2-7-diol, 2,3-butanediol, 1,4-cyclohexanedimethanol, polyoxyethylene

orpolyoxypropylene glycols or triols of molecular weights from about 200 to about

10,000,polytetramethylene glycols of varying molecular weight, poly( oxyethylene- oxybutylene)random or block copolymers, copolymers containing pendant hydroxy groups formed byhydrolysis or partial hydrolysis of vinyl acetate copolymers, polyvinylacetal resinscontaining pendant hydroxyl groups, hydroxy-functional (e.g., hydroxy - terminated)polyesters or hydroxy-functional (e.g., hydroxy -terminated) poly lactones, aliphaticpoly carbonate polyols (e.g., an aliphatic polycarbonate diol), hydroxy-functional (e.g., hydroxy -terminated) poly ethers (e.g., polytetrahydrofuranpolyols having a numberaverage molecular weight in the range of 150-4000 g/mol, 150-1500 g/mol, or 150-750g/mol), or a combination thereof. Examplepolyols further include aliphatic polyol, suchas glycerol, trimethylolpropane, and also sugar alcohol, such as erythritol, xylitol,mannitol or sorbitol. In particular embodiments, the coating of the coating formulation includes one or more alicyclic polyols, such as l,4-cyclohexane-dimethanol,sucrose, or 4,8- bis(hydroxymethyl)tricyclo(5,2, 1 ,0)decane. [0057] A suitable poly ether for the coating includes, in particular, linear orbranched polyglycol ether obtainable by ring-opening polymerization of cyclic ether in thepresence ofpolyol, e.g., the aforementioned polyol; polyglycol ether, polyethylene glycol,polypropylene glycol or polytetramethylene glycol or a copolymer thereof.

[0058] Another suitable polyester for the coating of the formulation includes apolyester based on polyols and aliphatic, cycloaliphatic or aromatic polyfunctionalcarboxylic acids (for example, dicarboxylic acids), or specifically all correspondingsaturated polyesters which are liquid at temperatures of 18°C to 300°C, typically 18°C tol 50°C: typically succinic ester, glutaric ester, adipic ester, citric ester, phthalic ester,isophthalic ester, terephthalic ester or an ester of corresponding hydrogenation products,with the alcohol component being composed of monomeric or polymeric polyols, forexample, of those of the above-mentioned kind.

[0059] Further polyester includes aliphatic polylactone, such as a-polycaprolactone, orpolycarbonate, which, for example, are obtainable by polycondensation of diol withphosgene. For the coating it is typical to use polycarbonate ofbisphenol A havingan average molecular weight of from 500 to 100,000.

[0060] For the purpose of influencing the viscosity of the coating and, inparticular, viscosity reduction or liquefaction, the polyol, poly ether or saturated polyesteror mixtures thereof may, where appropriate, be admixed with a further suitable auxiliary,particularly a solvent, a plasticizer, a diluent or the like. In an embodiment, thecompositions may comprise, relative to the total weight of the coating formulation, notgreater than about 15 wt. %, such as not greater than about 10 wt. %, not greater thanabout 6 wt. %, not greater than about 4 wt. %, not greater than about 2 wt. %, or about Owt. % of a hydroxy-functional component. In one example, the coating formulations arefree of substantial amounts of a hydroxy-functional component. The absence ofsubstantial amounts ofhydroxy-functional components may decrease the

hygroscopicityof the coating formulations or articles obtained therewith.

[0061] An example of a hydroxyl or an amine functional organic compound for

makingcondensation product with an alkylene oxide includes a polyol having 3 to 20

carbonatoms, a (C8-C18) fatty acid (C1-C8) alkanol amides like fatty acid ethanol amides, a fattyalcohol, an alkylphenol or a diamine having 2 to 5 carbon atoms. Such compounds arereacted with alkylene oxide, such as ethylene oxide, propylene oxide or mixtures thereof. The reaction may take place in a molar ratio of hydroxy or amine containing organiccompound to alkyleneoxide of, for example, 1 :2 to 1 :65. The condensation producttypically has a weight average molecular weight of about 500 to about 10,000, and may bebranched, cyclic, linear, and either a homopolymer, a copolymer or a terpolymer.

[0062] In an example, the coating composition can include an inorganic nano-wire. A nano- wire includes a nanostructure, such as a nano-fiber, with a diameter on the order of about 1 nanometer to about 30 nanometers, or more preferably from about 5 nanometers to about 20 nanometers. The diameter can include an average diameter of a plurality of nano-wires. In an example, a nano-wire can include a ratio of diameter to length (diameter: length) of about 1 :900 to about 1 : 4500. An average length of the inorganic nano-wire can be from about 5 micrometers to about 15 micrometers. In an example, the inorganic nano-wire can be a ceramic, including but not limited to silica, zirconium oxide, titanium di-oxide, alumina; metal/transition metal oxide such as zinc oxide, yttria, ytterbia, lanthanum; metal/transition metal nitride such as GaN, A1N; metal/transition metal arsenide such as GaAs; non-metal nitride/ arsenide such as Si3N4, BN, Si3As4; and carbon nano-wires. Examples of a metal oxide include ZnO, CdO, Si0₂,Ti0₂, Zr0₂, Ce0₂, Sn0₂, Mo0₃, W0₃, A1₂0₃, ln₂0₃, La₂0₃, Fe₂0₃, CuO, Ta₂0₅, Sb₂0₃,Sb₂0₅, or a combination thereof.

[0063] The inorganic nano-wires can have a wide band gap, such that the coating, when coated on a surface, does not decrease the transmittance of visible light. The inorganic nano- wire can, in an example, have a band gap above about 1.7 eV, preferably above about 3 eV. In an example, the inorganic nano-wires are mixed with other components of the coating composition so as to form an organic-inorganic hybridized structure. The inorganic non-wire can, in an example, be about 5 wt%, about 4 wt%, about 3 wt%, about 2 wt%, about 1 wt%, about 0.5 wt%, or about 0.1 wt% of the weight of the composition.

[0064] In an embodiment, additives can include a nano-sized particulate fillerthat is dispersed throughout the composite coating and comprises Ti0₂ particles, and Si0₂particles and/or A1₂0₃ particles. The composite coating is applied to a surface of thetransparent polymeric material, e.g., lens surface, and is polymerized (e.g. cured) to form acoated transparent polymeric material. When moisture condenses onto the surface of thecoated transparent polymeric material, e.g., lens temperature is significantly cooler thanthe surrounding air temperature, the composite coating exhibits photo-induced hydrophilicand self-cleaning properties to impart long-lasting anti-fog performance to the transparentpolymeric material. In particular, when the Ti0₂ particles in the composite coating areexposed to light energy in the presence of moisture, the Ti0₂ particles become energizedand effectively convert localized moisture into hydroxyl radicals. The hydroxyl radicalsact as powerful scrubbing agents that break up surface grime and oil and cause any waterdroplets to spread uniformly across the surface so that the transparent polymeric materialremains transparent.

[0063] The Si0₂ and/or AI2O3 particles further enhance the mechanical propertiesimparted by the composite coating, not only improving the scratch and abrasion resistanceof the coated transparent polymeric material but also helping to maintain the anti-fogperformance imparted by the Ti0₂ particles. In particular, the Si0₂ particles and A^C particles improve the durability and robustness of the composite coating so that the coatedtransparent polymeric material is more resistant to lens cleaning and normal handling. This helps to improve the scratch and abrasion resistance of the coated transparentpolymeric material and also to protect and maintain the effectiveness of the Ti0₂ particlesto provide even longer lasting anti-fog performance.

[0064] The particulate filler may be formed of inorganic particles, such as particles of,for example, a metal (such as, for example, steel, silver, or gold) or a metal complex suchas, for example, a metal oxide, a metal hydroxide, a metal sulfide, a metal halogencomplex, a metal carbide, a metal phosphate, an inorganic salt (like, for example, CaCC>3),a ceramic, or a combinations thereof. Examples of a metal oxide include ZnO, CdO, Si0₂,Ti0₂, Zr0₂, Ce0₂, Sn0₂, M0O₃, W0₃, AI2O3, ln₂0₃, La₂0₃, Fe₂0₃, CuO, Ta₂0₅, Sb₂0₃,Sb₂0₅, or a combination thereof. A mixed oxide containing different metals may also bepresent. The nanoparticles may include, for example, particles of ZnO, Si0₂, Ti0₂, Zr0₂,Sn0₂, A1₂C>3, co-formed silica alumina and a mixture thereof. In an embodiment, the nanoparticles comprise Ti0₂, and Si0₂ and/or A1₂C>3, for example Ti0₂,Si0₂, and A1₂C>3. The nanometer sized particles may also have an organic component,such as, for example, carbon monotones, a highly cross linked/core shell polymernanoparticle, an organically modified nanometer-size particle, etc. It should

beappreciated that since this application is for ophthalmic applications, the coatings areoptically clear, and, as a result, all the fillers are nanofillers so that they will not scatter thelight.

[0065] Particulate filler formed via solution-based processes, such as sol-formed andsol- gel formed ceramics are particularly well suited for use in the composite binder. Suitable sols are commercially available. For example, colloidal silicas in aqueoussolutions are commercially available under such trade designations as "LUDOX" (E. I.DuPont de Nemours and Co., Inc. Wilmington, Del), "NYACOL" (available from NyacolCo., Ashland, Mass.) and "NALCO" (available from Nalco Chemical Co., Oak Brook,Ill.). Many commercially available sols are basic, being stabilized by alkali, such assodium hydroxide, potassium hydroxide, or ammonium hydroxide. Cationicpolymerization cannot use basic solution since cationic photoinititator generates strongacid to open the epoxy ring for polymerization. Additional examples of suitable colloidalsilicas are described in U.S. Pat. No. 5,126,394, incorporated herein by

reference.Especially well-suited are sol-formed silica and sol-formed alumina. The sols can befunctionalized by reacting one or more appropriate surface-treatment agents with theinorganic oxide substrate particles in the sol.

[0066] In a particular embodiment, the particulate filler is sub-micron sized. Forexample, the particulate filler may be a nano-sized particulate filler, such as a particulatefiller having an average particle size of about 3 mm to about 500 nm. In an embodiment, the particulate filler has an average particle size of from about 3 nm to about200 nm, such as from about 3 nm to about 100 nm, about 3 nm to about 50 nm, about 8nm to about 30 nm, or about 10 nm to about 25 nm. In particular embodiments, theaverage particle size is not greater than about 500 nm, such as not greater than about 200nm, less than about 100 nm, or not greater than about 50 nm. In an embodiment, the particulate filler comprises particles ofTi0₂, and Si0₂ and/or Al₂0₃,such as Ti0₂, Si0₂, and Al₂0₃, having an average particle size of about 100 nm or less. For the particulate filler, the average particle size may be defined as the particle sizecorresponding to the peak volume fraction in a small-angle neutron scattering (SANS)distribution curve or the particle size corresponding to 0.5 cumulative volume fraction ofthe SANS distribution curve.

[0067] The particulate filler may also be characterized by a narrow distribution curvehaving a half- width not greater than about 2.0 times the average particle size. Forexample, the half- width may be not greater than about 1.5 or not greater than about 1.0. The half- width of the distribution is the width of the distribution curve at half itsmaximum height, such as half of the particle fraction at the distribution curve peak. In aparticular embodiment, the particle size distribution curve is mono-modal. In analternative embodiment, the particle size distribution is bi-modal or has more than onepeak in the particle size distribution.

[0068] In a particular embodiment, the particles of the particulate filler are

substantiallyspherical. Alternatively, the particles may have a primary aspect ratio greater than 1 , suchas at least about 2, at least about 3, or at least about 6, wherein the primary aspect ratio is the ratio of the longest dimension to the smallest dimension orthogonal to the longestdimension. The particles may also be characterized by a secondary aspect ratio defined asthe ratio of orthogonal dimensions in a plane generally perpendicular to the longestdimension. The particles may be needle-shaped, such as having a primary aspect ratio atleast about 2 and a secondary aspect ratio not greater than about 2, such as about 1. Alternatively, the particles may be platelet-shaped, such as having an aspect ratio at leastabout 2 and a secondary aspect ratio at least about 2.

[0069] In an embodiment, the particulate filler is prepared in an aqueoussolution and mixed with an external phase of the suspension. The process for preparingsuch suspension includes introducing an aqueous solution, such as an aqueous silicasolution; poly condensing the silicate, such as to a particle size of 3 nm to 50 nm; adjustingthe resulting silica sol to an alkaline pH; optionally concentrating the sol; mixing the solwith constituents of the external fluid phase of the suspension; and optionally removingwater or other solvent constituents from the suspension. For example, an aqueous silicatesolution is introduced, such as an alkali metal silicate solution (e.g., a sodium silicate orpotassium silicate solution) with a concentration in the range between 20% and 50% byweight based on the weight of the solution. The silicate is poly condensed to a particle sizeof 3 nm to 50 nm, for example, by treating the alkali metal silicate solution with acidic ionexchangers. The resulting silica sol is adjusted to an alkaline pH (e.g., pH>8) to stabilizeagainst further poly condensation or agglomeration of existing particles. Optionally, thesol can be concentrated, for example, by distillation, typically to Si0₂ concentration ofabout 30 to 40% by weight. The sol is mixed with constituents of the external fluid phase. Thereafter, water or other solvent constituents are removed from the suspension. In aparticular embodiment, the suspension is substantially water-free.

The fraction of the external phase in the pre-cured binder formulation, generallyincluding the organic polymeric constituents, as a proportion of the binder formulation canbe about 5% to about 95% by weight, such as about 20% to about 95% by weight, forexample, about 30% to about 95% by weight, and typically from about 50% to about 95%by weight, and even more typically from about 55% to about 80% by weight. The fractionof the dispersed particulate filler phase can be about 5% to about 95% by weight, such asabout 5% to about 80% by weight, for example, about 5% to about 70% by weight,typically from about 5% to about 50% by weight, and more typically from about 20% toabout 45% by weight. The colloidally dispersed and submicron particulate fillersdescribed above are particularly useful in concentrations of at least about 5 weight% (wt.%), such as at least about 10 wt. %, at least about 15 wt. %, at least about 20 wt. %, or asgreat as 40 wt. % or higher. In an embodiment, the colloidally dispersed andsubmicron particulate fillers comprise Ti0₂, and Si0₂ and/or AI2O3, and are inconcentrations of from about 5 wt. %to about 95 wt. %. In an embodiment,the Ti0₂ is in a concentration of about 20 wt. %, such as about 10 wt. %, for example offrom about 1 to about 5 wt. %. In another embodiment, the Si0₂ is in aconcentration of about 60 wt. % or less, for example of from about 1 to about 20 wt. %. Inanother embodiment, the AI2O3 is in a concentration of about 20 wt. % or less,for example of from about 1 to about 10 wt. %. In contrast with traditional fillers, thesolution formed of nanocomposites exhibit low viscosity and improved

processingcharacteristics at higher loading. The amounts of components are expressed as weight %of the component relative to the total weight of the composite binder formulation, unlessexplicitly stated otherwise.

[0070] In an example the coatingincludes an ionic surfactant and a non-ionic surfactant. In general, surfactants are configured for interacting with and modifying the surface of the particulate filler. The non-ionic surfactant can include one or more reactive groups that can be chemically bonded to a polymer matrix by a curing process, and wherein the polymer matrix is formed of cationically and radically polymerizable compounds. The one or more reactive groups can include vinyl, hydroxyl, carboxyl, acrylic, epoxy, urethane, amine, and wherein the curing process includes, UV, thermal, moisture, or chemical crosslinking. For example, a non- ionic surfactant may include organosiloxane, functionalized organisiloxane, alkyl-substituted pyrrolidone, polyoxyalkylene ether, ethyleneoxidepropyleneoxide copolymer or a combination thereof. For various particulate fillers and, in particular, for silica filler, a suitable surface modifier includes siloxane.

[0071] In general, the functionalized siloxane is a compound having a molecular weight ranging from about 300 to about 20,000. Such compounds are commercially available from, for example, the General Electric Company or from Goldschmidt, Inc. A typical functionalized siloxane is an amine functionalized siloxane wherein the functionalization is typically terminal to the siloxane.

[0072] Examples of suitbaleorganosiloxanes are sold under the name Silwet by Witco Corporation. Such organosiloxanes typically have an average weight molecular weight of about 350 to about 15,000, are hydrogen or C1-C4 alkyl capped and may be hydrolyzable or non- hydrolyzable. Typical organosiloxanes include those sold under the name of Silwet L-77, L-7602, L-7604 and L-7605, which arepolyalkylene oxide modified dialkylpolysiloxanes.

[0073] An example of a suitable ionic surfactant includes (C8-C16)alkylbenzenesulfonate, (C8-C16)alkane sulfonate, (C8-C18) a-olefin sulfonate, a-sulfo (C8-C16) fatty acid methyl ester, (C8-C16) fatty alcohol sulfate, mono- or di-alkyl sulfosuccinate with each alkyl independently being a (C8-C16)alkyl group, alkyl ether sulfate, a (C8-C16) salt of carboxylic acid or isethionate having a fatty chain of about 8 to about 18 carbons, for example, sodium diethylhexyl sulfosuccinate, sodium methyl benzene sulfonate, or sodium bis(2-ethylhexyl)sulfosuccinate (for example, Aerosol OT or AOT).

[0074] In a preferred example, the ionic surfactant is dioctyl sulfosuccinate sodium salt (DSS), which has the followin chemical structure:

[0075] The ionic surfactant can be at least marginally soluble in isopropanol (IPA). For example, the ionic surfactant can dissolve such that the coating composition is transparent. In an example, about 0.2 grams, about 0.3 grams, about 0.5 grams, about 0.6 grams, about 0.7 grams, 0.8 grams of DSS can dissolve in about 1.0 gram of IPA. The ionic surfactant can be dissolvable in a solution including at least one of IPA, methanol, and water.

[0076] The non-ionic surfactant can be a compound selected from an organosiloxane, a functionalisedorganosiloxane, an alkyl-substituted pyrrolidone, a polyoxyalkylene ether, or a ethyleneoxidepropylenenoxide block copolymer.

[0077] An example of a commercial surfactant includes a cyclic organo-silicone (e.g., SF1204, SF1256, SF1328, SF1202 (decamethyl-cyclopentasiloxane(pentamer)), SF1258, SF1528, Dow Corning 245 fluids, Dow Corning 246 fluids, dodecamethyl-cyclo-hexasiloxane (heximer), and SF 1173); a copolymer of a polydimethylsiloxane and a polyoxyalkylene oxide (e.g., SF1488 and SF1288); linear silicon comprising oligomers (e.g., Dow Corning 200 (R) fluids); Silwet L-7200, Silwet L-7600, Silwet L-7602, Silwet L-7605, Silwet L-7608, or Silwet L-7622; a nonionic surfactants (e.g., Triton X-100, Igepal CO-630, PVP series, Airvol 125, Airvol 305, Airvol 502 and Airvol 205); an organic polyether (e.g., Surfynol 420, Surfynol 440 and Surfynol 465); or Solsperse 41000.

[0078] Another commercial non-ionic surfactant includes SF1173 (from GE Silicones); an organic polyether like Surfynol 420, Surfynol 440, and Surfynol 465 (from Air Products Inc); Silwet L-7200, Silwet L-7600, Silwet L-7602, Silwet L-7605, Silwet L-7608, or Silwet L-7622 (from Witco) or non-ionic surfactant such as Triton X-100 (from Dow Chemicals), Igepal CO- 630 (from Rhodia), PVP series (from ISP Technologies) and Solsperse41000 (from Avecia).

[0079] The amount of ionic surfactant ranges from 0 wt. % to 10 wt. %. More typically, the amount of surfactant is between 0.1 wt. % and 5 wt. %. The silanes are typically used in concentrations from 40 mol. % to 200 mol. % and, particularly, 60 mol. % to 150 mol. % relative to the molecular quantity surface active sites on the surface of the nano-sized particulate filler. Generally, the coating formulation includes not greater than about 20 wt. % surfactant, including the ionic surfactant and the non-ionic surfactant, such as about 0.1 wt. % to about 10.0 wt. % surfactant, based on the total weight of the coating formulation. In an example, the coating formulation can have an ionic surfactant to non-ionic surfactant weight ratio (e.g., ionic : non- ionic) of about 1 :5, 1 :4, 1 :3, 1 :2, 1 : 1.

[0080] In a particular embodiment, the coating formulation includes about 10 wt.% toabout 90 wt. % cationically polymerizable compound, not greater than about 40 wt. %radically

polymerizable compound, and about 5 wt. % to about 80 wt. % particulate filler, based on the total weight of the coating formulation. It is understood that the sum of theamounts of the coating formulation components adds to 100 wt. % and, as such, whenamounts of one or more components are specified, the amounts of other componentscorrespond so that the sum of the amounts is not greater than 100 wt. %. In an embodiment, a weight ratio of the cationically polymerizable compound to the radicallypolymerizable compound is from about 1 : 1 to about 2: 1.

[0081] The cationically polymerizable compound, for example, includes an epoxy- functionalcomponent or an oxetane-functional component. For example, the coating formulation may include about 10 wt. % to about 60 wt. % cationically polymerizablecompound, such as about 20 wt. % to about 50 wt. % cationically polymerizablecompound based on the weight of the coating formulation. The example coating formulation may include not greater than about 20 wt. %, such as about 5 wt. % to about20 wt. % mono or poly glycidyl ethers of an aliphatic alcohol, aliphatic polyols,polyesterpolyol or polyetherpolyol. The examplecoating formulation may include notgreater than about 50 wt. %, such as about 5 wt. % to about 50 wt. % of a componenthaving a poly ether backbone, such as polytetramethylenediol, glycidylethers ofpolytetramethylenediol, and acrylates of polytetramethylenediol or

polytetramethylenediolcontaining one or more polycarbonate groups.

[0082] The radically polymerizable compound of the above example, for example,includes components having one or more methacylate groups, such as components havingat least 3 methacrylate groups. In another example, the coating formulation includes notgreater than about 30 wt. %, such as not greater than about 20 wt. %, not greater thanaboutl O wt. % or not greater than about 5 wt. % radically polymerizable compound.

[0083] The formulation may further include not greater than about 20 wt.%

cationicphotoinitiator, such as aboutO.1 wt. %to about 20 wt. %, or not greater than about 20 wt.%radical photoinitiator, such as about 0.1 wt.% to about 20 wt. %. For example, the coating formulation may include not greater than aboutl 0 wt. %, such as not greater thanabout 5 wt. % cationic photoinitiator. In another example, the coating formulation mayinclude not greater than aboutl 0 wt. %, such as not greater than about 5 wt.% free radicalphotoinitiator.

[0084] The particular filler includes dispersed submicron particulates. Generally, the coating formulation includes 5 wt. % to 80 wt. %, such as 5 wt. % to 60 wt. %, such as 5 wt. % to 50 wt. %, for example, 20 wt. % to 45 wt. % submicron particulate filler. Particular embodiments include at least about 5 wt. % particulate filler, for example at least about 10 wt. %, such as at least about 20 wt. %. In a particular embodiment, the particulate filler is solution formed silica particulate and may be colloidally dispersed in a polymer component. The example coating formulation may further include not greaterthan about 5 wt. % surfactant, such asO.1 wt. % to 5 wt. % surfactant, selected fromorganosiloxane, functionalisedorganosiloxane, alkyl-substituted pyrrolidone,polyoxyalkylene ether, and ethyleneoxidepropylenenoxide block copolymer.

[0085] In a particular embodiment, the coating formulation is formed by mixing

ananocomposite epoxy or aery late precursor, i.e., a precursor including submicronparticulate filler. For example, the coating formulation may include not greater than about90 wt. % nanocomposite epoxy and may include acrylic precursor, such as not greater than50 wt. % acrylic precursors. In another example, a nanocomposite acrylic precursor maybe mixed with epoxy.

[0086] The coating formulation including ancoating comprising polymeric ormonomeric constituents and including dispersed particulate filler may be used to form acoating that is applied to a surface of the ophthalmic lens, it is exposed to radiationpreferably in the ultraviolet range. Such radiation exposure causes the radically polymerizable polymer to rapidly cure creating a structure or lattice that retains thecationically polymerized polymer in place while it undergoes a slower photo curingprocess. As a result the cationically polymerized polymer cures in localized, encapsulatedenvironments as it is retained by the quickly cured radically

polymerizable polymer.

[0087] The coating system described herein is stable at room temperature andincludes a reduced solvent concentration thereby reducing the overall VOC impact of thematerial. The coating system is formed as an epoxy/acrylate cationic hybrid coating thatincludes two polymerization initiators, one of which commences polymerization uponexposure to ultraviolet radiation, while the other is a photo initiated catalyst. The coatingmay be further enhanced by the addition of colloidal nano-silica particles, such as Nanocryl CI 50 (e.g. reactive diluent/SiCh), that serve toreinforce the mechanical properties of the coating system without compromising theoverall transparency and optical clarity of the coating.

[0088] Further by employing a coating system such as described herein theepoxy/acrylate coating system is compatible with most dyes in a manner that allows theincorporation of infrared and near infrared energy filtering as well as the incorporation ofother coating additives that serve to enhance the cleaning, anti-fogging and anti-reflectiveproperties of the ophthalmic lens.

[0089] It is further preferred that the particular polymer substrate for the ophthalmic lensselected be well suited to the application in which the finished optical filter will beemployed. For example, lens blanks are typically formed using a polycarbonate whilewindows are formed using acrylic. In practical application, the filter blank is formed forfurther use as lens blanks, lenses for eyewear, windows and filtering plates.

[0090] It can therefore be seen that the present coating system provides a lens coating systemthat can be rapidly cured, offers the advantages of acrylate coatings yet has

improvedmechanical properties such as abrasion resistance. Further, the coating system described herein providesa coating system for application to a polymer ophthalmic lens that has improved abrasionresistance of the level of an epoxy coating, rapid curing of a radiation cured coating, whilealso being stable a room temperature, exhibiting low solvent/V OC content and supportingadditives for features such as anti-fog, easy cleaning, anti-reflection and

targetedwavelength filtering. For these reasons, the instant coating is believed to represent asignificant advancement in the art, which has substantial commercial merit.

[0091] In an example, a method for forming a coated substrate can include preparing inorganic nano-wires, such as the inorganic nano-wires described herein. The inorganic nano- wires can be prepared by a number of methods, including, but not limited to, a sol-gel method, a hydrothermal method, a template sacrificed method, a flame spray pyrolysis method, and the like. The prepared inorganic nano-wires can be dispersed in a solution to form a suspension. The suspension can include an organic solvent, such as, but not limited to an alkanol such as methanol, ethanol, isopropanol (IPA); ketones such as methylethylketone, methylisobutyl ketone, diacetone alcohol, 3,3-dimethyl-2-butanone, and pentanedione; N-methyl pyrrolidone;

acetonitrile; esters; glycol esters; and tertiary alcohols such astertiary-butyl alcohol and tertiary- amyl alcohol. In an example, dispersing can include at least one of physical stirring or sonication.

[0092] The method further contemplates mixing the suspension with a matrix solution to form a coating. The matrix solution can include at least one of a cationically polymerizable compound, including at least one epoxy group, and a radically polymerizable compound, including at least one acrylate group, and at least one surfactant (e.g., ionic or non-ionic surfactant), as described herein. The matrix solution can further include initiators, additives, and other compounds described herein. In an example, the inorganic nano-wires can be less than about 2 wt % of the formed coating.

[0093] In an example, the method can include cleaning a substrate, such as by any suitable method for preparing a substrate to have a coating applied. In one cleaning method example, an ultrasonic bath with a solution of dionized water and detergent is used, such as about 4 wt% detergent with a mix of Chem crest 14 and Chem crest 103 in a 3/2 weight ratio. A first rinse stage can include the solution at ambient temperature and ultrasonic cleaning. A second rinse can include the solution at about 60 °C and ultrasonic cleaning. A third and fourth rinse with the solution at about 60 °C without ultrasonic cleaning. Forced air can be used at about 70 °C for about 8 to about 12 minutes. The substrate can then be cooled, such as at ambient temperature, for about 10 to 15 minutes, prior to blowing off the substrate with ionized air to neutralize any static charge that may have built up during the drying process.

[0094] In another cleaning method, a hand washing process can be used to remove most dirt and dust particles from the substrate. An hand washing process can include, preparing a soap solution with about 0.75-1.5 wt% of mild dish detergent with warm H20. A pair of non- powdered latex or nitrile rubber gloves can be worn. Both sides of a test or reference lens should be contacted with water under a running tap prior to the application or cleaning with soap. A clean sponge or low lint wipe should be dipped into the soap solution and used to wipe the entire lens surface in a circular motion, such as at least 3 times per side. After the application of soap, the lenses should be rinsed under running tap water, such as at least 4 times per side. Next, the substrates should be rinsed several times with DI water, preferably from a squirt bottle or a running tap. A final rinse with a slow pull out of a beaker or container of DI water should be performed. For example, pull should take around 5 seconds for a typical lens. Such a pull substantially reduces or eliminates most drops and spotting. The lens should be inspected for any spots following the slow pull. Any droplets can be removed with dry, filtered air, or carefully absorbed with a low lint wipe. Oven dry the lens at about 50 to about 70 °C for 4-10 min and allow the lens to cool at ambient temperature for about 5 to about 10 minutes prior to coating. As mentioned herein, the substrates should be blown off with ionized air to neutralize any static charge that may have built up during the drying process.

[0095] The method can include applying at least a portion of the coating to the clean substrate. Applying the coating can include at least one of dip-coating, spray coating, a doctor blade method (e.g., a draw down method), spin coating, or the like. The applied coating can be cured, such as by thermal curing or UV curing, to form a coated substrate. In an example, a thickness of the cured coating can be from about 0.5 micrometers to about 20 micrometers, and preferably from about 1 micrometer to about 10 micrometers.

[0096] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In this document, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim.Moreover, in this document, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0097] From the foregoing, it will be observed that numerous variations and modifications can be effected without departing from the spirit and scope of the subject matter. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.

[0098] Although a few embodiments have been described in detail above, other modifications are possible. For example, the logic flows depicted in the FIGS, do not require the particular order shown, or sequential order, to achieve desirable results. Other steps can be provided, or steps can be eliminated, from the described flows, and other components can be added to, or removed from, the described systems. Other embodiments can be within the scope of the following claims.

Prophetic Examples:

Comparative Anti-Fog performance examples (Prophetic)

[0095] A UV curable organic-inorganic hybrid coating composition as illustrated in example 1.2. Example 1.1 is a control not containing inorganic nano-wires. Example 1.2 includes carbon nano-wires having an average diameter of about 5 nanometers to about 20 nanometers and an average length of about 5 micrometers to about 15 micrometers. Example 1.2 is prepared by dispersing, by soni cation, 0.002 grams of carbon nano-wires in 100 milliliters of IPA. Each coating is coated on the 76 mm polycarbonate lens blanks and followed by UV cure with combined Fusion D and H lamps at 50 ft/minute to give a dry thickness of 2 microns. Coated substrates from each composition areTaber tested and Bayer tested for evaluation of abrasion resistance and anti-scratch performance. The composition without carbon nano-wires will be used as reference to compare the effect of carbon nano-wires. The detailed compositions, in grams, Taber performance and Bayer performance are summarized in the tables below and FIG. 2.

Table 1. Examples 1.1 and 1.2 Compositions Component Example Example

1.1 1.2

ACHWL 4221 (difunctional 14.67 14.67

cycloaliphatic epoxy)

OXT-101 4.50 4.50

Chivacure 1 176 (cationic 0.63 0.63

initiator)

PEGDA (Mn 575) 30.40 30.40

Nanocryl c150 (reactive 8.00 8.00

diluent/Si0₂)

Chivacure 184 (free-radical 0.45 0.45

initiator)

I PA 35.24 35.24

Carbon nano-wires 0.00 0.007

Poly(ethylene glycol) dioleate 3.00 3.00

PEGDO (Mn = 1 120)

Total 96.89 96.8907

Table 2. Bayer Testing Results

[0096] As shown in FIG. 2 and Tables 1 and 2, Example 1.2 shows improved characteristics as compared to Example 1.1. For example, the Bayer Ratio of Example 1.2 is greater, indicating a high abrasion resistance than Example 1.1 which lacks the carbon nano- wires. Further, FIG. 2 illustrates the Taber testing results of Examples 1.1 and 1.2 with Delta Haze value on the y-axis and Running Cycles on the x-axis.. As shown in FIG. 2, plot 10 illustrates line A Taber testing results 12 corresponding to Example 1.1, lines B-1 and B-2 14, 16 are the Taber testing results for two tests of Example 1.2. As shown, lines 14 and 16, corresponding to Example 1.2, each have a lower delta haze value over the entire running cycles than that of Example 1.1, line A 12. A lower delta have value is associated with improved abrasion or scratch resistance (e.g., improved anti-scratch performance).

[0097] Accordingly, coating compositions for anti-fog coatings, methods for coating a surface to provide an anti-fog coated surface, and coated transparent polymeric materials have been described. In an embodiment, an improved coating system for transparent polymeric materials, such as ophthalmic lenses, provides improved characteristics in the form of anti-fog performance and scratch or abrasion resistance, and mitigation of surfactant diffusion, while also providing improved manufacturability and rapid curing as compared to prior art coating systems. Generally, the coating system is a composite coating that hybridizes at least one epoxy and acrylate coating materials into a single coating system with inorganic nano-wires. In this manner, the coating system exhibits the mechanical properties imparted by inorganic nano-wires in a hybridzed composition, such as, for example, increased abrasion resistance and reduced surfactant diffusion rates. The anti-fog coating is applied to a surface, such as of a transparent polymeric material, and is polymerized to form an anti-fog coated surface. When moisture condenses onto the surface of the coated transparent polymeric material, the composite coating exhibits photo-induced hydrophilic and self-cleaning properties to impart long-lasting anti-fog performance to the transparent polymeric material.

[0098] While at least one embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the embodiment or embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an embodiment described herein. It being understood that various changes may be made in the function and arrangement of elements described in anembodiment without departing from the scope of the detailed description as set forth in the appended claims.

Examples

[0098] Examples of the present application provide coating compositions and methods for forming a coated substrate with an organic-inorganic hybridized composition.

[0099] Example 1 includes subject matter directed toward a coating, comprising: at least one of a cationically polymerizable compound, including at least one epoxy group, and a radically polymerizable compound, including at least one acrylate group; an inorganic nano-wire; and at least one surfractant.

[00100] In Example 2, the subject matter of Example 1 can be optionally configured such that wherein the at least one surfactant includes one or more reactive groups that can be chemically bonded to a polymer matrix by a curing process, and wherein the polymer matrix is formed of cationically and radically polymerizable compounds. [00101] In Example 3, the subject matter of Examples 1 or 2 can be optionally configuredsuch thatwherein the one or more reactive groups comprises vinyl, hydroxyl, carboxyl, acrylic, epoxy, urethane, amine, and wherein the curing process includes, UV, thermal, moisture, or chemical crosslinking.

[00102] In Example 4, the subject matter of Examples 1-3 can be optionally configuredsuch thatwherein the at least one surfactant includes at least one of an ester, an ether, an ionic salt.

[00103] In Example 5, the subject matter of Examples 1-4 can be optionally configuredto further comprise: a radical polymerization initiator that causes polymerization of the radically polymerizable compound; and a cationic polymerization initiator that causes polymerization of the cationically polymerizable compound

[00104] In Example 6, the subject matter of Examples 1-5 can be optionally configuredsuch thatwherein the cationically polymerizable compound is about 10 wt% to about 90 wt% of the coating.

[00105] In Example 7, the subject matter of Examples 1-6 can be optionally configured such that wherein the radically polymerizable compound is less than about 40 wt% of the coating.

[00106] In Example 8, the subject matter of Examples 1-7 can be optionally configuredsuch thatwherein the inorganic nano- wire is less than about 2 wt% of the coating.

[00107] Example 9 the subject matter of Examples 1 -7 can be optionally configured such that wherein the inorganic nano-wire is at least one of a ceramic, zirconium oxide, titanium di-oxide, alumina, a metal/transition metal oxide, a metal/transition metal nitride, a metal/transition metal arsenide; a non-metal nitride/arsenide, and carbon nano-wires.

[00108] In Example 10, the subject matter of Examples 1 -9 can be optionally configuredsuch thatwherein the inorganic nano-wires have an average diameter of about 5 nanometers to about 20 nanometers.

[00109] In Example 11 , the subject matter of Examples 1 -10 can be optionally configuredsuch thatwherein the inorganic nano-wires have an average length of about 5 micrometers to about 15 micrometers.

[00110] In Example 12, includes the subject matter directed toward a method for forming a coated substrate, comprising: preparing inorganic nano- wired having an average diameter of about 5 nanometers to about 20 nanometers and an average length of about 5 micrometers to about 15 micrometers; dispersing, by sonication, the prepared inorganic nano-wires in a solution to form a suspension; mixing the suspension with a matrix solution to form a coating, the maxtrix solution including: at least one of a cationically polymerizable compound, including at least one epoxy group, and a radically polymerizable compound, including at least one acrylate group; and at least one surfractant; applying at least a portion of the coating to a substrate; and curing the applied coating to form a coated substrate.

[00111] In Example 13, the subject matter of Examples 1 -12 can be optionally configuredsuch thatwherein the applying includes at least one of dip-coating, spin-coating, spray-coating, and doctor blade.

[00112] In Example 14, the subject matter of Examples 1 -13 can be optionally configuredsuch that wherein the inorganic nano-wiresis at least one of a ceramic, zirconium oxide, titanium dioxide, alumina, a metal/transition metal oxide, a metal/transition metal nitride, a metal/transition metal arsenide; a non-metal nitride/arsenide, and carbon nano-wires.

[00113] In Example 15, the subject matter of Examples 1 -14 can be optionally configuredsuch thatwherein the inorganic nano-wires are less than about 2 wt% of the coating.

Claims

What is claimed is:

1. A coating, comprising:

at least one of a cationically polymerizable compound, including at least one epoxy group, and a radically polymerizable compound,including at least one acrylate group;

an inorganic nano-wire; and

at least one surfractant.

2. The coating of claim 1, wherein the at least one surfactant includes one or more reactive groups that can be chemically bonded to a polymer matrix by a curing process, and wherein the polymer matrix is formed of cationically and radically polymerizable compounds.

3. The coating of claim 2, wherein the one or more reactive groups comprises vinyl, hydroxyl, carboxyl, acrylic, epoxy, urethane, amine, and wherein the curing process includes, UV, thermal, moisture, or chemical crosslinking.

4. The coating of claim 1 , wherein the at least one surfactant includes at least one of an ester, an ether, an ionic salt.

5. The coating of claim 1, further comprising:

a radical polymerization initiator that causes polymerization of the radically

polymerizable compound; and

a cationic polymerization initiator that causes polymerization of the cationically polymerizable compound.

6. The coating of claim 5, wherein the cationically polymerizable compound is about 10 wt% to about 90 wt% of the coating.

7. The coating of claim5, wherein the radically polymerizable compound is less than about 40 wt% of the coating.

8. The coating of claim 1, wherein the inorganic nano-wire is less than about 2 wt% of the coating.

9. The coating of claim 1, wherein the inorganic nano-wire is at least one of a

ceramic, zirconium oxide, titanium di-oxide, alumina, a metal/transition metal oxide, a metal/transition metal nitride, a metal/transition metal arsenide; a non-metal nitride/arsenide, and carbon nano-wires.

10. The coating ofclaim 1, wherein the inorganic nano-wires have an average diameter of about 5 nanometers to about 20 nanometers.

11. The coating ofclaim 1 , wherein the inorganic nano-wires have an average length of about 5 micrometers to about 15 micrometers.

12. A method for forming a coated substrate, comprising:

preparing inorganic nano-wires having an average diameter of about 5 nanometers to about 20 nanometers and an average length of about 5 micrometers to about 15 micrometers; dispersing, by sonication, the prepared inorganic nano-wires in a solution to form a suspension;

mixing the suspension with a matrix solution to form a coating, the maxtrix solution including:

at least one of a cationically polymerizable compound, including at least one epoxy group, and a radically polymerizable compound, including at least one acrylate group; and

at least one surfractant;

applying at least a portion of the coating to a substrate; and

curing the applied coating to form a coated substrate.

13. The method of claim 12, wherein the applying includes at least one of dip-coating, spin- coating, spray-coating, and doctor blade.

14. The method of claim 12, wherein the inorganic nano-wiresinclude is at least one of a ceramic, zirconium oxide, titanium di-oxide, alumina, a metal/transition metal oxide, a metal/transition metal nitride, a metal/transition metal arsenide; a non-metal nitride/arsenide, and carbon nano-wires.

15. The method of claim 12, wherein the inorganic nano-wires are less than about 2 wt% of the coating.