Ruthenium-catalyzed surface polymer formation

Abstract

The present disclosure relates to ruthenium (Ru) catalysts and their use in surface polymer formations.

Description

[0001] Attorney Docket No. RAD-011WO

[0002] Ruthenium-Catalyzed Surface Polymer Formation

[0003] Cross-Reference to Related Applications

[0004] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 715,009, titled “Ruthenium-Catalyzed Surface Polymer Formation”, filed November 1 , 2024, the entire contents of which are incorporated by reference herein.

[0005] Field

[0006] Disclosed herein are ruthenium (Ru) catalysts and their use in surface polymer formations.

[0007] Background

[0008] Forming polymeric structures on surfaces have become increasingly important in many technologies and applications. “Surface polymers”, “surface bound polymers” or “polymers on a surface” all describe a polymeric structure having polymer chains that are chemically bonded to a surface at one end through covalently bound polymerization initiators. Two methods, known by persons skilled in the art, can be used to achieve such polymeric structure, namely the “grafting to”-approach and the “grafting from”-approach (see Fig. 1 and Fig. 2). In the “grafting to”- approach (Fig. 1), polymers are pre-prepared in solution and then deposited onto the surface in question, since the pre-prepared polymers are designed in such a way that one of the chain-ends has some affinity for the surface of interest. Upon contact with the surface of interest, the polymers will self-assemble on said surface forming surface bound polymers. In the “grafting from”- approach (Fig. 2), small molecules capable of acting as polymerization initiators are covalently bound to the surface of interest in a pre-polymerization step. Subsequently, polymerization is initiated via the polymerization initiators bonded on the surface. Accordingly, surface polymers are formed from the surface monomer-by-monomer.

[0009] While the “grafting to” approach allows for simple preparation procedures and detailed characterization, in that one can prepare the polymers using conventional polymerization methods that can maintain the bonding -to-surface property at the one end of the pre-formed polymer, before initiating the self-assembly procedure, the “grafting to”-approach lacks the ability to form high density surface bound polymeric structures nor flexibility in polymer structures, composition, etc. Main equilibrium conformation of long polymeric structures in solution is a contracted, or a coiled polymer chain, unless the polymer solution is extremely diluted with highly solvating solvent or

[0010] IPTS / 2OO163O13.1 other means employed to stabilize extended conformation (e.g., pH for ionic polymers). Such extra means to stabilize extended polymer chain conformation may complicate and interfere with the “grafting to” process conditions and make the approach less practical. Therefore, the self-assembly process is being halted by the steric repulsion between the coils of pre-made polymer chains as they self-assemble on the surface leading to loosely packed polymer coils on the surface (see Fig. 1). The “grafting from"-approach allows for the formation of highly dense surface bound polymer structures, as the small initiating molecules can form a much more densely packed layer on the surface (compared to large polymer molecules, see Fig. 2). Such a densely packed layer of initiating molecules is guiding monomer molecule-by-monomer molecule formation of polymer chains, where the extended conformation of growing polymer chains is sterically stabilized by their close proximity to each other. As such, the surface bound polymer structure formed by a “grafting from” approach results in a much higher density of polymer chains. Additionally, as the “grafting from”-approach allows for highly dense surface bound polymer structures, a brush-like structure can be achieved, thus, the name “polymer brush”. In these structures, the polymers are stretched and forced to stand upright due to the steric repulsion between neighbouring polymers creating a unique structure known by people skilled in the art as a “polymer brush” structure. On surfaces, these structures are tethered / attached, usually covalently, at one end to the surface, typically to a solid or semisolid surface, thereby differing from polymers formed in solution and subsequently deposited onto a surface.

[0011] As mentioned above, surface polymers are prepared by one of the following two main strategies: “grafting to” or “grafting from”. In the “grafting to”-approach, polymer chains are deposited onto the surface in question. The “grafting to”-approach suffers from several drawbacks and limitations making it difficult to produce thick and dense surface polymers. In the “grafting from”-approach, the surface polymer growth (surface polymer chain propagation, extension of the chain by monomer units) is initiated from initiator-functionalized surfaces, using, for example, a controlled / ”living” polymerization technique, such as anionic polymerization, cationic polymerization, ring-opening polymerization, and controlled radical polymerization.

[0012] Surface polymers within the present context are, thus, polymeric structures having polymer chains that are chemically bonded to a surface at one end via polymerization initiators. Such polymers may be tailored to provide specific chemical and / or physical properties and may produce precisely tailored chemical structures on a molecular scale. They may be used, for example, for storing certain chemical species, controlling transport properties, improving surface stability and properties, creating an interface in which dissimilar materials can bind or interact, and other functions. Surface polymers may subsequently join otherwise incompatible materials such as metals and plastics and improve adhesion between such otherwise incompatible materials (see, e.g., WO 2014 / 075695 Al).

[0013] Different polymerization techniques have facilitated the specific design and synthesis of surface polymers with strict molecular control and desired properties. In particular, the surface polymers can be viewed as nanoscale “building blocks” with a wide range of uses, varying from redox activity to biocompatibility and surface alteration, and due to the flexibility of the surface polymers, highly tailored thin films of surface polymers can be created with respect to chemical composition, thickness, density and architecture.

[0014] The various polymerization techniques use a catalyst to initiate surface polymerization. Cu catalysts have been studied widely in the field of surface polymers and polymerizations. In some applications, it could be beneficial to catalysts not being a Cu-based catalyst to achieve higher control of polymerization or specifically to avoid Cu impurities in the resulting surface polymer film. Accordingly, there is a need for the development of alternative catalysts.

[0015] Summary

[0016] In an aspect of the present disclosure, a method for forming surface polymers on a substrate is provided, the method comprising providing a substrate, wherein the substrate has polymerization initiators on at least a portion of a surface of the substrate, or wherein the substrate has polymer molecules on at least a portion of a surface of the substrate, exposing the substrate to a reaction composition comprising a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, a catalyst activator, and a solvent, to form surface polymers on the substrate. The Ru compound is a Ru(III) or a Ru(II) compound. The Ru compound may be RuCh, RuCb, RuCh hydrate, or RuCb hydrate. In the method, the solvent may be aqueous. The solvent may be a combination of methanol and water, ethanol and water, or isopropanol and water. In the method, the catalyst activator may be selected from sodium ascorbate (NaAsc), ascorbic acid (Asc), hydrazine, hydrazine hydrate, sodium thiosulfate, sodium sulfite, sodium dithionite, glucose with GOx, and / or pyrogallic acid. In the method, reaction composition may comprise a buffer and / or a zwitterionic buffer. The buffer is selected from carbonate buffer, glycine buffer, citrate buffer,

[0017] IPTS / 2OO163O13.1 phosphate buffer, acetate buffer, ammonium buffer (ammonium chloride / ammonia), formate buffer, and / or sodium ascorbate / ascorbic acid buffer. The zwitterionic buffer may be a Good’s buffer selected from MES, PIPES, MOPS, HEPES, CHES, CAPSO and / or CAPS. In the method, the ligand may be a nitrogen-containing ligand. The ligand may be a heterocyclic nitrogencontaining ligand. The ligand may be selected from WA'’,.V”, / V'”-pentamethykliethylene- triamine (PMDETA), tris[2-(dimethylamino)ethyl]amine (MeeTREN), tris(2-aminoethyl)amine (TREN), tris(2-pyridylmethyl)amine (TPMA), 1, 1,4,7, 10, 10-hexamethyltriethylenetetramine (HMTETA), tetramethylethylenediamine (TMEDA), 1, 4, 8, 11 -tetramethyl- 1, 4, 8, 11 -tetraazacyclo- tetradecane (Me4Cyclam), 2,2’ -bipyridyl (BiPy), and / or pyridine. In the method, the monomer may be selected from methyl methacrylate (MMA), methacrylate (MA), allyl methacrylate (AMA), glycidyl methacrylate (GMA), 2-hydroxyethyl methacrylate (HEMA), N-hydroxyethyl acrylamide (HEAM), 2-hydroxyethyl acrylate (HEA), tert-butyl acrylate (tBA), styrene, vinylimidazole (VI), N- vinylpyrrolidone, and vinylpyridine (VPY).

[0018] In an aspect of the present disclosure, a method for forming a surface polymer on a substrate is provided, the method comprising providing a substrate, exposing at least a portion of the surface of the substrate to a polymerization initiator, and exposing the substrate to a reaction composition comprising a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, a catalyst activator, and a solvent. The method may further comprise exposing the substrate having surface polymers on at least a portion of a surface of the substrate to a reaction composition comprising a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, a catalyst activator, and a solvent. In the method, the Ru compound is a Ru(III) compound or a Ru(II) compound. The Ru compound is RuCh, RuCh, RuCE hydrate, or RuCh hydrate. In the method, the solvent may be aqueous. The solvent may be a combination of methanol and water, ethanol and water, or isopropanol and water. In the method, the catalyst activator may be selected from sodium ascorbate (NaAsc), ascorbic acid (Asc), hydrazine, hydrazine hydrate, sodium thiosulfate, sodium sulfite, sodium dithionite, glucose with GOX, and / or pyrogallic acid. In the method, the reaction composition may comprise a buffer and / or a zwitterionic buffer. The buffer may selected from carbonate buffer, glycine buffer, citrate buffer, phosphate buffer, acetate buffer, ammonium buffer (ammonium chloride / ammonia), formate buffer, and / or sodium ascorbate / ascorbic acid buffer. The zwitterionic buffer may be a Good’s buffer selected from MES, PIPES, MOPS, HEPES, CHES, CAPSO and / or CAPS. In the method, the ligand may be a nitrogen-containing ligand. The ligand may be a heterocyclic nitrogen-containing ligand. The ligand may be selected from A,V / V’,A”,A”’-pentamethyldiethylene-triamine (PMDETA), tris[2- (dimethylamino)ethyl] amine (MeeTREN), tris(2-aminoethyl)amine (TREN), tris(2-pyridyl- methyl)amine (TPMA), 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA), tetramethylethylenediamine (TMEDA), 1,4, 8,11 -tetramethyl- 1,4, 8,11 -tetraazacyclotetradecane

[0019] (NfetCyclam), 2,2’ -bipyridyl (BiPy), and / or pyridine. In the method, the monomer may be selected from methyl methacrylate (MMA), methacrylate (MA), allyl methacrylate (AMA), glycidyl methacrylate (GMA), 2-hydroxyethyl methacrylate (HEMA), N-hydroxy ethyl acrylamide (HEAM), 2-hydroxyethyl acrylate (HEA), tert-butyl acrylate (tBA), styrene, vinylimidazole (VI), N-vinylpyrrolidone, and vinylpyridine (VPY).

[0020] In an aspect of the present disclosure, a system for forming surface polymers on a substrate is provided, the system comprising a reaction composition container containing a reaction composition, said reaction composition comprising a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, and a catalyst activator, and a substrate displacement device for bringing at least a portion of a polymerization initiator-modified substrate into contact with the reaction composition in the reaction composition container for a controlled time, wherein the controlled time is sufficient for surface polymers to be formed on the portion of the polymerization initiator-modified substrate. The substrate displacement device may comprise any one of a conveyor system, a programmable mechanical arm, or a roll-to-roll mechanism. The system may further comprise a polymerization initiator container containing a polymerization initiator agent, wherein the substrate displacement device is configured to bring the portion of the substrate for attachment of polymerization initiators into contact with the polymerization initiator agent to form polymerization initiators at the substrate surface, prior to bringing the portion of the polymerization initiator-modified substrate into contact with the reaction composition. The polymerization initiator container may be a vacuum oven. The system may comprise one or more cleaning containers, each cleaning container containing a cleaning agent, wherein the substrate displacement device is configured to bring the portion of the polymerization initiator-modified substrate into contact with the cleaning agent prior to, or subsequent to, bringing the portion of the polymerization initiator-modified substrate into contact with the reaction composition, and / or the substrate displacement device is configured to bring the substrate into contact with the cleaning agent prior to, or subsequent to, bringing the portion of the substrate into contact with the polymerization initiator or the reaction composition. The system may further comprise one or more containers for pre-wetting the at least a portion of the substrate prior to bringing the at least a

[0021] IPTS / 2OO163O13.1 portion of the substrate into contact with the reaction composition. The system may further comprise a reaction composition management system. The reaction composition management system may comprise one or more sensors in relation to the reaction composition container. The system may further comprise one or more flow control devices. The one or more flow control devices may be selected from circulation pumps, flow guidance grids, filters, and / or mechanical stirring means. The system may further comprise a heating device for annealing the substrate prior to, or subsequent to, bringing the at least a portion of the polymerization initiator-modified substrate into contact with the reaction composition.

[0022] In an aspect of the present disclosure, a polymer may be formed on at least a portion of at least a surface of a substrate by the methods as disclosed herein.

[0023] Description of the drawings

[0024] Certain embodiments of the matter disclosed herein are illustrated in the accompanying drawings. The drawings are, however, in no way intended to limit the scope of the disclosure. In the drawings:

[0025] Fig. 1 illustrates the “grafting to” principle.

[0026] Fig. 2 illustrates the “grafting from” principle.’

[0027] Fig. 3 illustrates the principle of grafting density of polymerization initiators to “dummy” initiators (non-polymerization initiators).

[0028] Fig. 4 is a schematic illustration of a system for forming surface polymers on at least a portion of a surface of a substrate, according to embodiments of the present invention.

[0029] Fig. 5 is a schematic illustration of an exemplary substrate displacement device, the substrate displacement device comprising a roll-to-roll processing device, in accordance with an embodiment.

[0030] Fig. 6 represents the inventors’ suggestion of the Ru / ligand complex 200, showing the ligand 201 complexed with ruthenium 202 and the two vacant sites 203, 204.

[0031] Fig. 7 represents the inventors’ suggestion of the Ru / ligand complex 300, showing the ligand 301 complexed with ruthenium 302 with one of the vacant sites of Fig. 6 being occupied with a polymerization initiator 303 and the other vacant site 304 being vacant.

[0032] IPTS / 2OO163O13.1 Fig. 8 represents the inventors’ suggestion of the Ru / ligand complex 400, showing the ligand 401 complexed with ruthenium 402, and the two vacant sites 203, 204 of Fig. 6, one vacant site being occupied by a C-C double bond (C=C) or a C-0 double bond (C=O) 403 of a monomer, and one vacant site being occupied by a polymerization initiator 404.

[0033] Fig. 9 represents the inventors’ suggestion of the Ru / ligand complex 500, showing the ligand 501 complexed with ruthenium 502, and the two vacant sites 203, 204 of Fig. 6, one vacant site being occupied by presumably partially a polymer molecule of a substrate 503, and one vacant site still being vacant 504.

[0034] Fig. 10 represents the inventors’ suggestion of the Ru / ligand complex 600, showing the ligand 601 complexed with ruthenium 602, and the two vacant sites 203, 204 of Fig. 6, being occupied either by presumably partially a polymer molecule of a substrate 603, and a C-C double bond (C=C) or a C-0 double bond (C=O) 604 of a monomer.

[0035] Detailed description

[0036] In an aspect of the present disclosure, a ruthenium (Ru) catalyst is provided. The ruthenium catalyst may be useful for catalyzing the formation of surface polymers on at least a portion of a surface of a substrate. In some instances, surface polymers may be formed from polymerization initiators present on at least a portion of a surface of a substrate. In some instances, surface polymers may be formed from polymer molecules on at least a portion of a surface of a substrate.

[0037] Herein, the terms “ruthenium” and “Ru” may be used interchangeably. Herein, “ruthenium catalyst” and “Ru catalyst” may be used interchangeably. Herein, “ruthenium compound” and “Ru compound” may be used interchangeably. Herein, the Ru compound may be referred to as “Ru catalyst” when in combination with a ligand, i.e., Ru catalyst and ligand, or Ru catalyst / ligand.

[0038] In an aspect of the present disclosure, a method for forming surface polymers on a substrate is provided, the method comprising providing a substrate having polymerization initiators on at least a portion of a surface of the substrate, exposing the substrate to a reaction composition to form surface polymers via the polymerization initiators on the substrate, the reaction composition comprising a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, a catalyst activator, and a solvent. In an aspect of the present disclosure, a method for forming surface polymers on a substrate is provided, the method comprising providing a substrate having polymer molecules on at least a portion of a surface of the substrate, exposing the substrate to a reaction composition to form surface polymers via the polymer molecules on the substrate, the reaction composition comprising a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, a catalyst activator, and a solvent.

[0039] Within the present context, the term “surface polymer” is intended to mean a plurality of polymer molecules, each polymer molecule being composed of a number of repeating units. The number of repeating units may be s few as from 2-20 (often denoted “oligomer”) or up to several thousands.

[0040] In the reaction composition to be used with the disclosed method, the “catalyst / ligand formed from a ruthenium (Ru) compound and a ligand” may be present as the catalyst / ligand preformed from the ruthenium (Ru) compound and the ligand, or be present as the ruthenium (Ru) compound and the ligand. By way of example, a solution of the Ru compound and the ligand may be prepared and a certain amount added to the reaction composition together with the other components. By way of example, all components of the reaction composition may be mixed, in any order, including the Ru compound and the ligand.

[0041] In some instances, the method for forming a surface polymer on a substrate involves providing a substrate, exposing the substrate to a polymerization initiator, and exposing the substrate to a reaction composition comprising a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, and a solvent, to form the surface polymer from the polymerization initiators present on at least a portion of the surface of the substrate.

[0042] In some instances, the method of forming a surface polymer on a substrate involves providing a surface polymer substrate, exposing the surface polymer substrate to a reaction composition comprising a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, and a solvent, to form the surface polymer from the surface polymer substrate.

[0043] Within the present context, the expression “a portion of the surface” is intended to mean that a surface of the substrate may have one or more areas with polymerization initiators, or, in some

[0044] IPTS / 2OO163O13.1 cases, polymer molecules. A substrate may have one or more surfaces, and each surface may comprise one or more areas with polymerization initiators, or, in some cases, polymer molecules.

[0045] Herein, the Ru compound may be a Ru(III) or Ru(II) compound. The term “Ru(III)” is intended to mean Ru in oxidation state III. The term “Ru(II)” is intended to mean Ru in oxidation state II. The Ru compound may be provided as a hydrate. The Ru compound may be provided as an anhydrate. The Ru compound may be present both as a Ru(III) compound and a Ru(II) compound. Examples of Ru(III) compounds include, but are not limited to RuCh, and RuCh hydrate. Examples of Ru(II) compounds include, but are not limited to, RuCh, and RuCh hydrate.

[0046] The Ru catalyst concentration in the reaction composition may generally be in the range 0.001-1 mM. Specifically, the concentration of catalyst in the reaction composition may be in the range 0.02-0.32 mM, for example 0.02 mM, 0.04 mM, 0.08 mM, 0.16 mM, or 0.32 mM.

[0047] In accordance with the above, a method for forming surface polymers on a substrate is provided, the method comprising providing a substrate having polymerization initiators on at least a portion of a surface of the substrate, exposing the substrate to a reaction composition comprising a monomer, a catalyst / ligand complex formed from RuCh or RuCh hydrate, and a ligand, a catalyst activator, and a solvent, to form surface polymers via the polymerization initiators on the substrate.

[0048] In some instances, the method comprises providing a substrate, exposing the substrate to a polymerization initiator, and exposing the substrate to a reaction composition comprising a monomer, a catalyst / ligand complex formed from RuCh or RuCh hydrate, and a ligand, and a solvent. Exposing the substrate to a polymerization initiator covalently attaches the polymerization initiator to the surface of the substrate.

[0049] In accordance with the above, a method comprises providing a substrate having polymer molecules on at least a portion of a surface of the substrate, exposing the substrate to a reaction composition to form surface polymers via the polymer molecules on the substrate, the reaction composition comprising a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, a catalyst activator, and a solvent.

[0050] In some instances, surface polymers may be formed from polymerization initiators attached to at

[0051] IPTS / 2OO163O13.1 least a portion of a surface of a substrate. Attachment of polymerization initiators to a surface of a substrate, from which surface polymers may be propagated, may be performed by various procedures. Polymerization initiators are covalently bonded to the surface of the material, see, e.g., WO 2014 / 0075695. The polymerization initiators may be provided with a predefined chemistry to enable attachment onto the surface of the substrate, depending on the nature of the substrate. Nonlimiting examples of suitable chemistries for attaching polymerization initiators on surfaces include but are not limited to: aryl diazonium salts, organosilanes, organothiols, organophosphonic acids, organophosphonates, catechols, iodonium salts, alkenes, alkynes, and sol-gel coatings. Surface anchored polymerization initiators can be prepared as multilayer films or monolayer films. Monolayer films can be densely packed (full monolayer coverage) or partly packed, covering all or only a part of the available surface. The density of the polymerization initiator influences the density and may possibly influence the growth rate of the subsequently formed surface polymer. Density of polymerization initiators would be understood by persons of ordinary skill as the number of polymerization initiators per unit area of the substrate.

[0052] The attachment of polymerization initiators usually follows a 1-step or a 2-step process. The 1- step process applies grafting of benzyl halide (like benzyl chloride) or secondary or tertiary halide moieties onto the surface of the substrate either by diazonium or silane grafting. The benzyl halide and secondary and tertiary halide moiety act as the polymerization initiator for the following surface-initiated polymerization. The 2-step process usually applies surface grafting of an initial organic compound with a nucleophilic group, and in a second step using the nucleophilic group to attach an initiator moiety. The nucleophilic group may include a hydroxyl or amine group. Then, the nucleophilic group may be reacted with an electrophile to add an initiator moiety, forming a covalent bond between the two. The initiator moiety may be, e.g., benzyl halide and tertiary halide moieties.

[0053] The attachment process is further described below. The procedures may in general apply to all types of substrates. Prior to attachment of polymerization initiators to form the polymerization initiator layer, the surface of the substrate may be cleaned using various techniques, including sonication in ammonia, ABC-clean A200, a solution of DI-water:NH3:H2O2 (5:1 :1), acetone, and / or water, to mention some. In some instances, the substrates are subjected to the polymerization initiator forming process without any prior cleaning steps. Following attachment

[0054] IPTS / 2OO163O13.1 of polymerization initiators, the substrate may be rinsed and / or annealed at ambient conditions or at elevated temperatures.

[0055] Silane grafting 1-step:

[0056] Polymerization initiators may be attached to a surface in one step by silane grafting of trialkoxysilane with benzyl halide or tertiary halide groups. The silane grafting may be done by vapor deposition, in solution, by spray coating, or paint-on coating.

[0057] Diazonium grafting 1-step:

[0058] Polymerization initiators may be attached to a surface in one step by grafting aryl diazonium salts with benzyl halide groups. The diazonium grafting may be done either by activating the aryl diazonium salt electrochemically or chemically or by letting it react spontaneously. Diazonium salts may be pre-synthesized before being used for grafting reaction or formed in-situ during grafting reaction from a set of precursors added to the grafting reaction solution.

[0059] Diazonium grafting 2-step:

[0060] Another route of polymerization initiator attachment is by a two-step process. The first step being grafting of an aryl diazonium salt that contains a nucleophilic group (alcohol or amine). In a second step, a nucleophilic acyl substitution reaction adds a halogen containing group, giving the attached polymerization initiator.

[0061] Silane grafting 2-step:

[0062] The first step being grafting of a silane that contains a nucleophilic group (alcohol or amine). In a second step, a nucleophilic acyl substitution reaction adds a halogen containing group, giving the attached polymerization initiator.

[0063] Other processes for forming the polymerization initiator layer may be applied.

[0064] An example of a polymerization initiator is p-(chloromethyl)phenyltrimethoxysilane (CPTMS) which may be attached using a vapor deposition method or a dipping method. Another example is a-bromobutyryl bromide (BiBB). Another example is the polymerization initiator / ?-(chloro- methyl)phenyltrimethoxysilane (CPTMS) in combination with a “dummy” initiator phenyltrimethoxysilane (PTMS), acetyl bromid (AcBr), or (3-glycidyloxypropyl)trimethoxysilane

[0065] IPTS / 2OO163O13.1 (GPTMS), the latter which display an epoxy (epoxide) group suited for further modification by ring-opening of the epoxy (epoxide) group. Within the present context, the term “dummy initiator”, “non-polymerization initiator” or “initiator not initiating polymerization” is a chemical entity which does not initiate surface polymer formation in the presence of an active polymerization catalyst.

[0066] Thus, the presence of polymerization initiators in the polymerization initiator layer may be “diluted” by the simultaneous presence of “dummy” initiators to form a polymerization initiator layer containing polymerization initiators active for surface polymer formation and chemical entities (the “dummy” initiator) not active for surface polymer fomiation. The “dummy” initiator may be added in a certain percentage together with the polymerization initiator, thus, competing with the polymerization initiator about available attachment sites on the substrate surface. Dilution of the polymerization initiator with a “dummy” initiator may be used to adjust the density of the polymerization initiators on the surface of the substrate, thus, aiding in controlling density (“grafting density”, i.e. the number of surface polymer chains per unit area of the substrate) of subsequently formed surface polymers. Here “grafting” means monomer-by-monomer propagation of surface polymers from the polymerization initiators. The density of the initiators (both polymerization initiators and non-polymerization / ”dummy” initiators) influences the density of the subsequently formed surface polymer propagated from the polymerization initiator sites. As mentioned above, the density of polymerization initiators is intended to mean the number of polymerization initiators per unit area. Non-limiting examples of suitable percentage ratios (molecular-% (mol%) of polymerization initiator to non-polymerization initiator) may be in the range 100:0 (no non-polymerization initiator), 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, and 10:90. The principle of adjusting the grafting density of polymerizations with “dummy” initiators is shown schematically in Fig. 3. Fig. 3 shows a varying dilution of the polymerization initiator with a non-polymerization initiator (“dummy” initiator). Fig. 3 is not intended to be an exact representation of the grafting density nor the distribution of the polymerization initiators as compared to the “dummy” initiators. In Fig. 3, “right” schematically shows the polymerization initiator is present at all available sites, i.e. no “dummy” polymerization initiator present. In Fig. 3, “middle” and “left” schematically shows increasing presence of “dummy” initiators, with the “left” image showing a higher presence of “dummy” initiators as compared to the “middle” image. It is expected that a wide range of different substrates will be useful in connection with the disclosure herein. Substrates may wholly or partly be composed of metal (like aluminum, steel, nickel, gold, silver, platinum, chrome, copper, iron and alloys), glass, carbon, graphite, graphene, carbon black, monoclays, ceramics, composite materials, plastics, polymer materials, semiconductors, compound semiconductors (e.g., gallium arsenide (GaAs), gallium nitride (GaN), germanium sulfide (GeS), and indium phosphide (InP)), and particles (e.g., Si, metal, metal alloys and coated particles). Substrates may be patterned or unpattemed. If patterned, substrate surface(s) may comprise one or more of the mentioned substrate materials. The substrate may be composed of several layers of different materials, optionally being attached together, e.g., using a glue or by laminating, or be a blend of different materials. The substrate may have any size, shape and structure, including an elongated structure, and may be in the form of pieces, threads, fibers, cables, wires, hollow structures, particles, nanoparticles, monolayers etc. Particles and nanoparticles may be uncoated or coated with another material and may further be in the form of aggregates (multiple (nano)particles forming an assembly of individual (nano)particles). Aggregates may in some cases be viewed as one (nano)particle. Substrates may also be composed of one or more of the above mentioned, e.g., the substrate may be a base material comprising glass, silicon, GaAs, GaN, GeS, InP, dielectric material, ceramic, composite, as well as layered and patterned structures thereof. Substrates may have any form and shape, be elongated, be hollow, have protrusions or recesses, etc.

[0067] A portion or portions of a substrate may be “masked” so as to only attach polymerization initiators to unmasked areas on the substrate. Different techniques may be used to accomplish such specific attachment of polymerization initiators. For example, the portion or portions of the substrate may be covered by a film or layer during polymerization initiator attachment. Alternatively, contact between a portion or portions of a substrate and the reaction composition for forming surface polymer may be limited by, e.g., a masking with for example a film or a layer covering the portion or portions of the substrate on which surface polymers are not to be formed, or by immersing, into the reaction composition, only those portions of the substrate onto which surface polymers are to be formed. In general, any masking should be non-reactive with other chemistries to which the substrate is exposed and should be easily removable from the substrate.

[0068] Different polymerization techniques have facilitated the specific design and synthesis of surface polymers. In particular, the surface polymers can be viewed as nanoscale “building blocks” with

[0069] IPTS / 2OO163O13.1 a wide range of uses, varying from redox activity to biocompatibility and surface alteration, and due to the flexibility of the surface polymers, highly tailored thin films of surface polymers can be created with respect to chemical composition, thickness, density and architecture. However, methods and reagents supporting specific design, architecture and control of formation are continuously investigated.

[0070] Several methods for forming surface polymers are known, among them SI-ATRP (surface-initiated atom transfer radical polymerization), SI-RAFT (surface-initiated reversible-addition fragmentation chain transfer), SI-NMP (surface-initiated nitroxide-mediated polymerization), SIPIMP (surface-initiated photoiniferter-mediated polymerization), and SI-A(R)GET (surface- initiated activators (regenerated) by electron transfer) ATRP. A review is given in Chem. Rev. 2009, 109, 5437-5527. Other approaches include SET-LRP (single-electron transfer living radical polymerization) and SARA ATRP (supplemental activator and reducing agent atom transfer radical polymerization).

[0071] Polymerization initiators may firstly be formed on the surface or portion(s) of the surface onto which the surface polymers are to be formed. Secondly, the surface or portion(s) of the surface is brought into contact with suitable monomers, catalysts, ligands and optionally a solvent, or suitable monomers, catalyst, ligands, a reducing agent and optionally a solvent, whereby the surface polymer can form using certain reaction conditions. The polymerization initiators and the monomers are chosen so as to suit the purposes and properties of the resulting surface polymers. Surface polymers may also be formed as layers of surface polymers by repeating the polymeric architecture, e.g., using another starting monomer (so-called block copolymers).

[0072] Among these known procedures for formation of surface polymers, (ARGET) ATRP and SET- LRP are widely used. For the polymerizing chains to propagate, a monomer, a catalyst, a ligand and a solvent are needed. In (ARGET) ATRP and SET-LRP polymerizations, some reactions activate the catalyst, thereby, promoting polymerization, and at the same time, other reactions deactivate the catalyst to impede polymerization. SARA-ATRP and SET-LRP are described, e.g., in https: / / www.cmu.edu / maty / atrp-how / procedures-for-initiation-of-ATRP / SARA-ATRP-or-

[0073] SET-LRP.html. Both the SET-LRP and (ARGET) ATRP method rely on the formation of a complex between the ligand and a halide formed with a transition metal as specified in the Periodic Table (usually CuCh or CuBr2 in the case of ARGET ATRP, and Cu(0) in the case of SET-LRP, but other transition metals and halogens may be used).

[0074] The ARGET ATRP involves a halogen transfer between a dormant halogen capped species, Pn-X and Cu(I)X / L catalyst, resulting in the formation of a propagating radical (Pnradical) and Cu(II)X2. The propagating radical undergoes polymerization with monomers, forming the growing polymer chain. Controlling the ratio between Cu(I)X / L and Cu(II)X2 / L in ARGET ATRP allows control of the polymerization itself.

[0075] From WO 2019 / 196999 Al, which is incorporated by reference in its entirety, as if fully set forth herein, an alternative oxygen-tolerant method for forming surface polymers is disclosed. The catalyst / ligand complex described in WO 2019 / 196999 Al is halogen free in so far as the catalyst / ligand complex formed is not complexed with a halogen anion as the catalyst / ligand complex formed is a catalyst oxide. An advantage is that the complex (pre-)formed between the transition metal and the ligand is inactive (i.e., not available for initiating polymerization of the monomer) and furthermore stable (oxygen-insensitive), but the system can be activated “on demand” by a reducing agent / catalyst activator, thus, initiating polymerization and propagation of the surface polymers.

[0076] The ruthenium compounds disclosed herein offer an alternative to the generally applied Cu- containing catalysts. The catalysts based on ruthenium compounds may be useful in applications, where Cu-containing catalysts may be less desirable. In some instances, the ruthenium compounds may provide a polymerization rate and profile different from conventionally used Cu-containing catalysts, thus, providing polymerization control beneficial for some applications.

[0077] In accordance with the methods disclosed herein, the substrate including one or more surfaces of the substrate, or portions of one or more surfaces of the substrate may be brought into contact with the reaction composition for surface polymer formation. It is to be understood that the surfaces or portions of the surfaces of the substrate may have been subjected to attachment of polymerization initiators prior to contact with the reaction composition. It is to be understood that the surfaces or portion of the surfaces of the substrate may have or be composed of a plurality of polymer

[0078] IPTS / 2OO163O13.1 molecules. It is to be understood that the components of the reaction composition may be mixed and subsequently be brought into contact with the substrate. In another embodiment, the components of the reaction composition may be prepared as discrete compositions and mixed prior to or following contact with the substrate. E.g., the monomer may be prepared as a discrete component (solvated in the solvent if needed), and the catalyst / ligand complex may be brought into contact with the catalyst activator, whereafter the activated catalyst / ligand complex may be brought into contact with the substrate, followed by addition of the monomer. E.g., the monomer, the catalyst / ligand complex, and the solvent may be brought into contact with the substrate, and the catalyst activator may be dissolved in the solvent and subsequently be added. E.g., the monomer, the catalyst / complex, the solvent, and the catalyst activator may be pre-mixed, and subsequently be brought into contact with the substrate.

[0079] For forming surface polymers, the substrate and the reaction composition as defined herein are typically kept in contact with each other for a suitable time period (residence time or polymerization time), sufficiently to form surface polymers essentially having an average dry film thickness within a desired range. The polymerization time may be as long as needed. Suited polymerization times include, but is not limited to, up to 24 hours, e.g., 2 seconds, 5 seconds, 10 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds, 1 minute, 5 minutes, 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours and 5 hours. For a manufacturing perspective, polymerization times between 20 seconds and 20 minutes may often be suitable. The surface polymer formation may take place at ambient temperature (room temperature), or with cooling or heating. Suitable temperatures include, but are not limited to, such from 5°C up to 120°C, such as from room temperature (approximately 20°C) to 120°C. Specific temperatures include, but are not limited to, 5°C, 10°C, 15°C, 20°C, room / ambient temperature (approximately 20°C), 30°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, and 120°C. The polymerization time and temperature during the polymerization time may suitably be computer controlled. Following formation of surface polymers, the substrate may be subjected to optionally multiple rinsing and cleaning processes, typically involving flushing with a suitable solvent, sonicating, and / or drying at room temperature or elevated temperature (“annealing”).

[0080] It is to be understood that by the term “thickness of a surface polymer” or “thickness of a polymer on a surface” is meant the surface polymer film formed on the substrate, i.e., the surface polymer as defined herein. The thickness is often measured as the dry film thickness by ellipsometry but

[0081] IPTS / 2OO163O13.1 may be measured by other means such as reflectometry or by measuring a step edge in the coating by atomic force microscopy or profilometry. To determine the dry film thickness, several ellipsometry measurements are taken in evenly spaced positions on the substrate surface. At a beam incidence angle of 65° the beam spot of the ellipsometer, i.e., the area from which each measurement collects data for the thickness calculation, is approximately 0.16 cm2. E.g., for a 2" silicon wafer quadrant substrate (total area of -20.3 cm2), different data collection routines may include 10, 45, or more measurement spots, meaning that the area from which thickness data is collected ranges from 1.6 cm2to 7.2 cm2or more, corresponding to thickness data being obtained from 7.8 % to 35.5 % of the total surface area. Adding more measurement points to the measurement routine would mean that average dry film thickness data would be obtained from a larger fraction of the surface area, although the inventors generally find that the good homogeneity of the surface polymers presented herein may suffice for determining the average dry film thickness of a surface polymer. Generally speaking, a substrate with a surface polymer film may be considered dry when no visible solvent film, droplets, or residues are observed, by visual inspection, on the surface of the substrate. Measurements such as atomic force microscopy and profilometry demand that a step edge is made in the coating from the outer edge of the coating and all the way to the surface of the substrate, by e.g. scratching. In the dry state, the surface-tethered polymer molecules acquire a conformation between fully collapsed and stretched conformation where the degree of stretching depends on the grafting density.

[0082] The ruthenium (Ru)-catalyzed surface polymer formation offers control of the polymerization and the obtained average dry film thickness of the surface polymers. The polymerization time influences the obtained average dry film of the surface polymer, however, with the ruthenium (Ru) catalysts disclosed herein surface polymers of a desired average dry film thickness may easily be controlled. In some instances, the average dry film thickness of the surface polymer may be up to approximately 500 nm. In some instances, the average dry film thickness of the surface polymer may be up to approximately 250 nm. In some instances, the average dry film thickness of the surface polymer may be up to approximately 150 nm. In some instances, the average dry film thickness of the surface polymer may be up to approximately 130 nm. In some instances, the average dry film thickness of the surface polymer may be up to approximately 100 nm. In some instances, the average dry film thickness of the surface polymer may be up to approximately 75 nm. In some instances, the average dry film thickness of the surface polymer may be up to approximately 50 nm or less. In some instances, the average dry film thickness may be up to approximately 10 nm. Here, the term “approximately” is intended to be within ± 20% of the stated average dry film thickness. In some instances, the “approximate” may be within ± 10%, ± 5% or less. It has been shown herein (Examples) that the polymerization can be controlled so as to yield surface polymers within the mentioned thicknesses.

[0083] For forming surface polymers, the solvent of the reaction composition may be aqueous. Thus, the solvent may be a mixture of water and an organic solvent. The water and the organic solvent may be miscible with each other. Suitable solvents include, but are not limited to, alcohols, dipolar aprotic solvents (for example, tetrahydrofuran, methyl acetate, ethyl acetate, butyl acetate, dimethyl sulfoxide, dimethyl formamide), methylene carbonate, ethylene carbonate, propylene carbonate, ethyl lactate alcohol, toluene, ionic liquids, and supercritical CO2. The solvent may be chosen so as to provide sufficient solubility and / or miscibility of the components of the reaction composition. The ratio (volume-% (vol%)) between water and organic solvent may be 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, or 90:10 as well as range therebetween.

[0084] The solvent may be a combination of water and methanol, water and ethanol, or water and isopropanol. The solvent may be a combination of water and methanol, ethanol, and / or isopropanol.

[0085] The solvent may solubilize the other components of the reaction composition. Some of the components may be solubilized in the solvent prior to the surface polymer formation and mixed with the remaining components. Thus, any of the monomer, the catalyst and the ligand, and the catalyst activator may be solubilized in the solvent prior to surface polymer formation. Nonlimiting ways of mixing include: mixing of catalyst, ligand and solvent prior to mixing with catalyst activator optionally solubilized in solvent, or mixing of catalyst, ligand, solvent, and catalyst activator prior to addition of monomer optionally solubilized in solvent, or mixing of catalyst, ligand, solvent, and monomer prior to addition of catalyst activator solubilized in solvent. It is to be understood that “solvent” in the aforementioned cases may include water alone, or a mixture of water and organic solvent. Other ways of mixing of the components of the reaction composition may be envisaged, and, thus, the order of mixing of the components should not be restricted to the disclosure of the Examples.

[0086] IPTS / 2OO163O13.1 The Ru compound and the ligand form a complex. It is believed that a catalyst activator should be present to activate the reaction composition for surface polymer formation. Suited catalyst activators include, but are not limited to, sodium ascorbate (NaAsc), ascorbic acid (Asc), hydrazine, hydrazine hydrate, sodium thiosulfate, sodium sulfite, sodium dithionite, glycose, glucose with GOX(glycose with oxidizing enzyme), and / or pyrogallic acid. The catalyst activator may be used in excess compared to the catalyst. Excess catalyst activator may, e.g., be 10-500 times.

[0087] In some instances, the reaction composition may comprise a buffer. It is hypothesized that a buffer may stabilize the complex formed between the Ru compound and the ligand to control surface polymerization. The inventors speculate that the buffer may to some extend result in the formation of Ru species, the formation of which may aid in catalyzing the polymerization. The term “buffer” is defined herein as an agent which, when added to the reaction composition, can within a certain pH range withstand changes in pH when acidic or alkaline substances / components are added to the reaction composition or is formed in the reaction composition. Buffer systems include combinations of a weak acid and its conjugate base, or a weak base and its conjugate acid. Buffers may suitably be prepared as an aqueous solution but may in some cases involve adding a nonaqueous solution or solid / semi-solid formulation to the reaction composition.

[0088] Non-limiting examples of buffers are carbonate buffer, glycine buffer, citrate buffer, phosphate buffer, acetate buffer, ammonium buffer (ammonium chloride / ammonia), formate buffer, sodium ascorbate / ascorbic acid buffer, and / or zwitterionic buffers. Non-limiting examples of zwitterionic buffers are a Good’s buffer selected from MES, PIPES, MOPS, HEPES, CHES, CAPSO and / or CAPS.

[0089] The ligand to be applied in the methods described here may be a nitrogen-containing ligand. In some embodiments, the ligand may be a heterocyclic nitrogen-containing ligand. Non-limiting examples include A,A,A’,A”,A”’-pentamethyldiethylene-triamine (PMDETA), tris[2- (dimethylamino)ethyl] amine (MeeTREN), tris(2-aminoethyl)amine (TREN), tris(2-pyridyl- methyljamine (TPMA), 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA), tetramethylethylenediamine (TMEDA), 1,4, 8,11 -tetramethyl- 1,4, 8,11 -tetraazacyclotetradecane (Me4Cyclam), 2,2’ -bipyridyl (BiPy), and / or pyridine. Pyridine derivatives may also be suited ligands. The amount of ligand in the reaction composition may suitably be defined as a ratio to the

[0090] IPTS / 2OO163O13.1 concentration of catalyst in the reaction composition. The ratio of ligand to catalyst in the reaction composition may be in the range 0.001: 1 to 1000:1. The ratio of ligand to catalyst in the reaction composition may, in some embodiments, be in the range 0.005: 1 to 100:1, for example 0.13:1, 0.5:1, 1.0: 1, 2.0: 1, 3.5:1, 7.5:1 or 12: 1. In general, an excess amount of ligand as compared to amount of catalyst may be used.

[0091] The reaction composition may in some cases comprise a halide compound for increasing the “livingness” of the polymerization. A “living” polymerization refers to a polymerization where the rate of termination is minor in comparison to the rate of propagation of polymer molecules from the polymerization initiators. As a result, living polymerizations show a more linear relationship between polymer chain length and time. The halide compound to be used herein is a compound capable of providing a halide anion. Non-limiting examples of such compounds are NaCl, NaBr, KC1, KBr, MgCh, MgBr2, CaCl2, HC1, HBr, LiCl, LiBr, CaBr2, as well as combinations thereof. Halide compounds may disassociate in the reaction composition, generating halide anions which may form complexes with and / or bind to catalysts in solution, resulting in an increased concentration of catalyst / ligand-X (X is the halide anion) complexes which are responsible for end-capping, and thus deactivating, propagating surface polymer chain-end radicals to deliver alkyl halides. Consequently, the number of propagating surface polymer chainend radicals at any given time is lowered, which may result in at least the following effects; (1) a lowering of the rate with which polymer molecules grow initially due to a lower number of propagating chains, and (2) a lowering of the rate with which chain termination between two propagating polymer molecule chain-end radicals occur (through recombination or disproportionation), leading to an increased living character of the polymerization. The halide compound may suitably be used in the range of from 0.1 M to 2 M.

[0092] Surface polymers are formed from monomers present in the reaction composition. Monomer(s) may be chosen to provide compatibility / adhesion / elasticity / hydrophilicity surface properties, as appropriate for a specific application. Monomer(s) can also be selected to enhance or diminish electrical and / or ionic conductivity, and / or permeability. Monomers may be chosen to improve interface stability of a surface in question. Furthermore, the introduction of functional groups or combination of functional groups may provide improvement over various desired properties, like density, dielectric constants, diffusion barrier, wettability, etc. Monomers may suitably be used in an amount corresponding to a percentage of the total volume of the reaction composition (see formula (I)). For example, a liquid monomer may constitute e.g. 0.5 vol%, 2 vol%, or 10 vol% of a reaction composition. In accordance with the present disclosure, an amount of monomer may be chosen to obtain desired surface polymerization kinetics, solubility of the monomer, and cost of the monomer. The monomer may suitably be used in the range 0.5 vol% to 50 vol%.

[0093] The formation of surface polymers may be performed at ambient temperature, at a temperature above ambient temperature, or at a temperature below ambient temperature. The temperature during surface polymer formation may be controlled automatically. The polymerization time may vary depending on components of the reaction composition, the targeted average dry film thickness of the surface, process optimization, etc.

[0094] Following formation of the surface polymer, the formed surface polymer is indicated with a “P” as prefix to the monomer. By way of example, methyl methacrylate monomer is denoted MMA, and after polymerization, the polymer molecule is denoted PMMA. Likewise, 2-hydroxyethyl methacrylate is denoted HEMA, and after polymerization, the polymer molecule is denoted PHEMA.

[0095] The surface polymer formed may be composed of several types of monomeric units. Such “mixed” surface polymers may be obtained as a result of formation of co-polymers. Co-polymers may be in the form of random co-polymerization (two or more monomers present in a certain ratio), or block co-polymerization (two or more consecutive polymerization events).

[0096] Thus, non-limiting examples of appropriate monomer types include anionic, cationic, zwitterionic, protic and aprotic monomers, and include acrylates, methacrylates, halogen-substituted alkenes, acrylamides, methacrylamides, and styrenes, as well as mixtures thereof. The generic monomer structure comprises a polymerizable part (a vinyl group), which in certain embodiments is connected to a functional group responsible for the specific functionality (e.g., adhesion, permeability, electric and ionic conductivities) of the certain monomer through a certain linker chemistry.

[0097] For acrylate monomers, non-limiting examples of functional moi eties include but are not limited to alkyl groups, aryl groups, sulfonates, fluorosulfonates, carboxyls, metal carboxylates, ethers, poly(ether) groups, bis(sulfonyl)amides, fluorinated sulfonates, perfluoroalkyl carboxylate, borate, fluorinated borate, borate ester derivatives, bis(trifluoromethane)sulfonimide, triflimides and derivatives thereof, halogenated alkyl chains, and mono-, di-, and tri-alkoxy silanes.

[0098] The polymerizable part and the functional part of monomer can, in certain embodiments, be connected by a linker moiety. Non-limiting examples of appropriate linker chemistries include but are not limited to alkyl chain, esters, ethers, poly(ethers), amines, amides, aryls, and any combination(s) thereof. Non-limiting examples of appropriate acrylate monomers containing alkyl linkers include but are not limited to methyl acrylate, ethyl acrylate, and lauryl acrylate. Nonlimiting examples of monomers using ether and poly(ether) linker chemistry include but are not limited to poly(ethylene glycol) methyl ether acrylate, and poly(ethylene glycol) acrylate. Nonlimiting examples of monomers without linker chemistry include but are not limited to acrylic acid, lithium acrylate, sodium acrylate, and vinyl imidazole.

[0099] For methacrylate monomers, non-limiting examples of appropriate functional moieties include but are not limited to carboxylic acids, metal carboxylates, esters, alkyl alcohols, oxiranes (epoxides), linear and branched alkyl groups, alkenes, aryl groups, sulfonates, fluorosulfonates, bis(sulfonyl)amides, fluorinated sulfonates, perfluoroalkyl carboxylate, borate, fluorinated borate, borate ester derivatives, bis(trifluoromethane)sulfonimide, triflimides, and derivatives thereof, halogenated alkyl chains, and mono, di, and tri-alkoxy silanes.

[0100] Non-limiting examples of linker chemistries include but are not limited to alkyl chains, esters, ethers, poly(ethers, amines, amides, aryls, and any combination(s) thereof.

[0101] Non-limiting examples of methacrylate monomers include but are not limited to methacrylic acid, lithium methacrylate, sodium methacrylate, methyl methacrylate (MMA), potassium 3-sulfpropyl methacrylate (K-SPMA), 2-hydroxyethylmethacrylate (HEMA), glycidyl methacrylate (GMA), ethyl methacrylate, / / -butyl methacrylate (BuMA), tert-butyl methacrylate (tBMA), lauryl methacrylate, (((perfluorobutyl)sulfonyl)oxy)methyl methacrylate, 3-(N-((trifluoromethyl)- sulfonyl)sulfamoyl)propyl methacrylate, \H, lH,2H,2H-heptadecafluorodecyl methacrylate (HFDMA), allyl methacrylate (AMA), 2-((triethoxysilyl)oxy)ethyl methacrylate, and 2-(3- (triethoxysilyl)propyl)ethyl methacrylate. Non-limiting examples of acrylate monomers include but are not limited to methyl acrylate (MA), tert-butyl acrylate (tBA), lauryl acrylate (LA), and 2-hydroxyethylacrylate (HEA).

[0102] Non-limiting examples of appropriate halogen-substituted alkene monomers include but are not limited to vinyl chloride, vinylidene difluoride, tetrafluoroethylene, chlorotrifluoroethylene, and hexafluoropropylene.

[0103] Non-limiting examples of appropriate acrylamide monomers include but are not limited to acrylamide, A-zso-propylacrylamide, A-tert-butylacrylamide, and A-hydroxyethyl acrylamide.

[0104] Non-limiting examples of appropriate methacrylamide monomers include but are not limited to N- Ao-propylmethacrylamide, methyl methacrylamide, A-terz-butylmethacry lamide, and A'-hydroxy- ethyl methacrylamide.

[0105] Non-limiting examples of appropriate styrene monomers include but are not limited to styrene, 4- methylstyrene, 2,3,4,5,6-pentafluorostyrene, p-divinylbenzene, 4-chlorostyrene, sodium 4- vinylbenzenesulfonate, lithium 4-vinylbenzenesulfonate, and 4-vinylphenyl 1, 1,2, 2, 3, 3, 4,4,4- nonafluorobutane- 1 -sulfonate.

[0106] As mentioned above, the surface polymers described herein may also be copolymers. Within the present context, the expression “co-polymer” or “co-polymers” is intended to mean a polymer molecule of the surface polymer as defined herein comprising at least two different monomeric repeat units. Co-polymers may be formed by copolymerizing different types of monomers or by subsequent partial chemical modification of a homopolymer (within the surface polymer) to add a chemical modification of one type of monomeric repeat unit to obtain a different type of monomeric repeat unit. Repeating the steps of the methods described herein multiple times may provide formation of multiple layers of surface polymers (block co-polymers, b-polymers).

[0107] The surface polymer may possess specific properties obtained through block co-polymers, random polymers, or binary mixed polymer, resulting in a surface polymer with a difference in surface polymer architecture. In such embodiments, the different monomers of block co-polymers, random polymers or binary mixed polymers may contribute with different properties resulting in a surface polymer with a combination of desired properties. Also, forming block co-polymers, random polymers or binary mixed polymers may provide an overall thicker surface polymer, i.e. a surface polymer with higher average dry film thickness. Two or more functional groups (e.g., halogen atoms, hydroxyl groups, or amine groups) can be incorporated, resulting in surface polymers with a unique set of combined properties, each of which is inherent from individual monomers. Formation of block co-polymers, and random polymers are usually formed as a result of a “living" polymerization where the formed surface polymer has viable chain-ends that may initiate further polymerization in subsequent polymerization events.

[0108] The “monomer-by-monomer” approach (“grafting from” approach) for formation of surface polymers offers myriads of monomer types and combinations thereof in forming surface polymers of desired structure, composition, and properties. The methods presented herein have proven sufficiently oxygen insensitive to make possible the polymerization to generally take place under ambient atmospheric conditions, and this offers a flexibility in the design of surface polymers as well as in the preparation of them, including high-volume manufacturing.

[0109] Surface polymers formed on a substrate may be analyzed, e.g., by ellipsometry according to the following procedure. Ellipsometry provides a measurement of the average dry film thickness of the surface polymer across the substrate or a portion of a substrate. Generally speaking, a substrate with a surface polymer (is herein considered dry when no visible solvent film, droplets, or residues are observed with the naked eye on the surface of the substrate. Other methods of obtaining a dry substrate may be used, some of which include withdrawal of the substrate(s) from the reaction composition, followed by rinsing by sonication in Dl-water for 5 minutes, followed by sonication in acetone for 5 minutes, and drying in ambient air 1-30 minutes. In some cases, the substrates may be flushed with acetone after withdrawal from the reaction composition, followed by airdrying in an oven at 80°C for 15 minutes. Still, in some cases, the substrate(s) may be flushed with acetone, then sonicated in acetone for 5 minutes and left to dry at 80°C for 10 minutes. Alternative, the substrate(s) may be flushed with isopropanol (iPrOH), then sonicated in iPrOH for 5 minutes and left to dry under nitrogen flow for 10-30 minutes. Then, the substrate may be subjected to ellipsometry.

[0110] In an aspect of the present disclosure, a reaction composition is provided, the reaction composition comprising a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, a catalyst activator, and a solvent. Upon contact between the reaction composition and a substrate having polymerization initiators on at least a portion of a surface, surface polymers may be formed on the substrate.

[0111] The Ru compound may be RuCh, RuCh, RuCh hydrate, or RuCh hydrate.

[0112] Suitable monomers, ligands, catalyst activators, solvents are disclosed above in connection with the methods discussed herein.

[0113] It is to be understood that the reaction composition comprises the individual components mentioned (monomer, catalyst / ligand formed from a Ru compound and a ligand, catalyst activator, and solvent) whether or not the components are already mixed or provided separately for mixing.

[0114] In an aspect of the present disclosure and encompassed within the disclosure, a polymer formed on at least a portion of a substrate is provided. The surface polymer may be formed using the methods and the reaction compositions disclosed herein. The surface polymer may also be formed on a system as disclosed herein, operable according to the methods described herein.

[0115] Thus, a polymer formed on at least a portion of at least a surface of a substrate may be formed by the methods disclosed herein.

[0116] The inventors have recognized a surprising property of the Ru catalyst. The Ru catalyst has shown an unexpected potential in initiating a polymerization formation from both polymerization initiators on a substrate, and from polymer molecules of a substrate.

[0117] Thus, in an aspect of the present disclosure, a method of initiating a polymer formation on a substrate is provided, the method comprising providing a substrate having at least a surface of polymer molecules, exposing the substrate to a reaction composition comprising a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, a catalyst activator, and a solvent, to form surface polymers via the polymer molecules of the substrate. In some instances, the substrate may be composed of polymer molecules (be a polymer material). In some instances, the substrate may be such, where a surface polymer of a plurality of polymer molecules are formed on at least a portion of the substrate by a method comprising providing a substrate having polymerization initiators on at least a portion of a surface of the substrate, exposing the substrate to a reaction composition comprising a monomer, a catalyst / ligand complex formed from a catalyst and a ligand, a catalyst activator, and a solvent, to form the surface polymer of the plurality of polymer molecules via the polymerization initiators on the substrate, and exposing the substrate to a reaction composition comprising a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, a catalyst activator, and a solvent, to form further surface polymers via the polymer molecules on the substrate. The method of forming the surface polymer of a plurality of polymer molecules may not be important as the Ru catalyst may be able to initiate surface polymer formation from the polymer molecules irrespective of how the initial surface polymer formation was performed. For example, Cu catalysts like copper chlorides, and copper oxides, or Ru catalysts as defined herein may be applied. In the method described in the foregoing, solvents and catalyst activator may suitably be those described herein. The method may be performed under inert conditions, or atmospheric conditions.

[0118] In accordance with the above, the inventors have sought to relate the experimentally surprising findings to a chemical mechanism of Ru-catalyzed surface polymer formation. It is to be understood that scope of this disclosure should not in any way be limited by this proposed mechanism. It is known that Cu-catalyzed surface polymerization or polymerization in solution tend to reach a plateau for the molecular size (Mn) of the polymer within a certain polymerization time. For formation of surface polymers, this corresponds to a halt, or at least a very slow propagation of surface polymers as a function of time. This behavior is believed to be due to endtermination of viable ends on the polymer or surface polymer. This may be interpreted as an overactivation of polymerization which results in loss of viable chain-ends. A loss in viable chainends minimizes the further polymerization initiation potential, implying that additional polymerization cannot take place. As demonstrated herein, it was surprisingly found that the Ru catalyst as defined herein was able to initiate polymerizations despite end-termination in a surface polymer formation experiment where initiation of surface polymer formation using the Ru catalyst is compared with an attempt to initiate surface polymer formation using a Cu catalyst.

[0119] Without being bound by a specific catalytic mechanism, the inventors hypothesize that the Ru- catalyzed polymerization utilizes a different mechanism compared to that of, e.g., copper- catalyzed polymerizations. The inventors propose a mechanism as shown in Fig. 6 through Fig. 10.

[0120] In Fig. 6, the inventors propose that the Ru / ligand complex 200, when bound to a ligand 201, has two vacant sites 203, 204.

[0121] The inventors imagine that these two vacant sites may be able to coordinate with certain organic molecules. In accordance herewith and as shown in Fig. 7, the Ru / ligand complex 300 (the ligand 301 and ruthenium 302) may coordinate, at a vacant site, the polymerization initiator 303, whereas the Ru / ligand complex 300 still has a vacant site 304. In accordance herewith and as shown in Fig. 8, the Ru / ligand complex 400 (of ligand 401 and ruthenium 402) may coordinate a C-C double bond (C=C) or a C-0 double bond (C=O) 403, on a monomer, at one vacant site, and at the other vacant site coordinate a polymerization initiator 404. The schematic, hypothetical mechanisms shown in Fig. 7 and Fig. 8, respectively, could explain the ability of the Ru catalyst to initiate surface polymer formation due to insertion of the C=C double bond (C=C) between the Ru / ligand complex and the initiator, resulting in a one vacant site 504 and polymer molecule of a substrate 504 occupying the other vacant site as shown in Fig. 9. Fig. 9 and Fig. 10 show a schematic illustration of how the inventors imagine the initiation of surface polymer formation and propagation of the surface polymer from a polymer molecule of a substrate 604 alternating with the vacant site being occupied by a C-C double bond (C=C) or C-0 double bond (C=O). This alternation is shown in Fig. 9 and Fig. 10, respectively. The inventors propose that the concurrent presence of a C-C double bond (C=C) and C-0 double bond (C=O) may be beneficial as the C=O may provide a “guidance” effect for the incorporation of the monomer. The inventors further propose that the presence of a methyl group (CH3) on or in close proximity of the C-C double bond (C=C) may further facilitate incorporation of the monomer.

[0122] For the mechanism shown in Fig. 6 through 10, monomers containing a C=C, optionally in combination with a C=O may be specifically interesting, that is, methacrylates, acrylates, methacrylamides, acrylamides, styrenes, and acrolein or derivatives thereof, as well as olefins in general, to mention some. Specific, non-limiting, examples include methyl methacrylate (MMA), glycidyl methacrylate (GMA), 2-hydroxyethyl methacrylate (HEMA), methacrylate (MA), 2- hydroxyethyl acrylate (HEA), A(2-hydroxyethy I (methacryl amide (HEMAm), A-hydroxy ethyl acrylamide (HEAm), styrene (St), methacrolein, methyl vinyl ketone, ethyl vinyl ketone, vinyl alcohol, A- Vinylpyrrolidone, cis-2-pentene, and trans-2-pentene, hex-l-ene, hex-2-ene, hex-3 -ene. Fig. 4 is a non-limiting schematic illustration of a system 100 for forming surface polymers on at least a portion of a substrate. The methods described herein may be operable on a system as described in the following. The system 100 comprises a reaction composition container 104, or one or more reaction containers 104, containing the aforementioned reaction composition 105. Container(s) 104 may relate to any vessel or chamber suitable for holding the reaction composition. At least a portion of a substrate 102 (which may be polymerization initiator-modified or may display polymer molecules) is brought into contact with the reaction composition 105, for example by at least partly immersing a desired surface of substrate 102 into the reaction composition, thereby enabling surface polymers to form on the substrate. The reaction composition (that is the catalyst, the ligand, the catalyst activator, the solvent, and the monomer) is disclosed in the foregoing.

[0123] Optionally, system 100, may comprise one or more further containers, each container comprising different compositions and / or agents for treating the substrate 102, either prior to the substrate being brought into contact with the reaction composition 105, or afterwards. Where substrate 102 has not been pre-treated with a polymerization initiator, then the system 100 may further comprise a container 107 holding a polymerization initiator chemistry 106, thus, forming the polymerization initiator-modified substrate 102 in the container 107. As mentioned above, a portion or portion of substrate 102 may be masked, e.g., by applying a film or a layer, so as to enable attachment of polymerization initiators only to a portion or portions onto which surface polymers are to be formed subsequently.

[0124] When Fig. 4 relates to an embodiment in which the substrate has been pre -coated with a polymerization initiator, or where it is a desire to pre-treat the substrate, a cleaning container (or one or more, i.e., multiple cleaning containers, as needed) 114 may be provided, comprising cleaning agent(s) or cleaning device(s) 116. The cleaning agent / device 116 may be used to clean the surface of substrate 102 prior to bringing it into contact with reaction composition 105 held by the reaction composition container 104. This may be achieved by, at the very least, subjecting at least a portion of the substrate 102 on which it is desired to form surface polymers on, to cleaning procedures in container 114 using cleaning agent / device 116. In this way, any impurities which may interfere with the formation of the surface polymers, are removed from the surface of substrate 102, prior to bringing substrate 102 into contact with the reaction composition 105. System 100

[0125] IPTS / 2OO163O13.1 may additionally include a substrate displacement device 103 for bringing the substrate 102 at least partly into contact with the reaction composition 105 held by the reaction composition container 104 for a controlled time to ensure surface polymers form. The expression “at least partly” is intended to mean that a portion or portions of substrate 102 is brought into contact with the reaction composition 105. The displacement device 103 may be configured to control the contact between substrate 102 and reaction composition 105. Alternatively, as mentioned above, the portion or portions of substrate 102 may be covered (“masked”) by, e.g., a film or a layer suited for avoiding contact between reaction composition 105 and the substrate 102. The displacement device 103 may be used to remove the substrate 102 from the reaction composition 105 following surface polymer fomration. Thus, the substrate displacement device 103 may be configured to maintain the surface of substrate 102 at least partly in contact with the reaction composition 105 to enable surface polymers to form on at least a portion of the surface of the substrate, and the substrate displacement device 103 may be configured to maintain the substrate 102 in contact with the reaction composition 105 for a predetennined amount of time.

[0126] In instances where the system 100 may comprise two or more containers, such as illustrated in Fig. 4, in addition to bringing substate 102 into contact with the compositions contained by each container, the substrate displacement device 103 may be configured to transport substrate 102 to and from each container. For example, as illustrated in Fig. 4, the substrate displacement device 103 may be configured to firstly transport substrate 102 into contact with cleaning agent / device 116 in container 114, and / or a polymerization initiator chemistry 107 if the substrate is not precoated with a polymerization initiator as mentioned previously, held in the container 106, and subsequently to transport the substrate 102 from the container 106 to the reaction composition container 104, where the substrate is brought at least partly into contact with the reaction composition 105 held by the reaction composition container 104. In the latter example, the substrate may in embodiments be cleaned between initiator coating and surface polymer formation. In some instances, system 100 may comprise multiple cleaning containers in sequence (not shown).

[0127] System 100 as shown in Fig. 4 may further be equipped with a reaction composition management system (not shown). The reaction composition management system may include one or more sensors in relation to the reaction composition container 104. The one or more sensors may be configured to measure a characteristic of the reaction composition 105, which characteristic may relate to a physical or chemical characteristic of the reaction composition 105, such as the pH of the reaction composition and / or the molecular oxygen concentration in the reaction composition. The sensor data may be used to determine whether a value of the measured characteristic lies within a predetermined threshold for the surface polymer formation process. If the measured characteristic is determined to lie outside the predetermined threshold, then the chemistry of the reaction composition 105 may be adjusted by dispensing different chemistries to reaction composition container 104 to adjust the value of the measured characteristic, e.g., an acidic or an alkaline substance to adjust the pH value of the reaction composition 105 or a substance to control the oxygen concentration of the reaction composition 105. In this way, it is possible to ensure that the values of the one or more characteristics of the reaction composition are within a range suitable for forming desired surface polymers on the substrate 102. A control unit operatively connected to the one or more sensors, may be used to control one or more dispensers for dispensing one or more chemistries to control the chemistry of the reaction composition 105.

[0128] Similarly, the chemistry of the reaction composition 105 may be adjusted by dispensing any one or more of the components of the reaction composition into the reaction composition 105. For example, the components may relate to any one or more of: at least one monomer, at least one ligand, at least one catalyst, at least one catalyst activator, and at least one solvent. In some embodiments, the control unit may be configured to output a control signal for controlling operation of a dispenser for dispensing one or more components of the reaction composition into the reaction composition 105, in response to the measured characteristic of the reaction composition 105, or in response to an observed time variance of the characteristic. For example, a value of the measured characteristic may be monitored over a time period using the one or more sensors. The control unit may determine to output a control signal to control operation of one or more dispensers to dispense the one or more components on the basis of an observed variation over time of the measured characteristic. The observed variation may be indicative that the chemistry of the reaction composition 105 is varying such that the surface polymer formation process is falling out of specification - for example, surface polymer formation is reduced and / or compromised. The dispensing of one or more components of the reaction composition into the reaction composition 105 may help to maintain one or more chemical properties of the reaction composition 105, to enable the formation of surface polymers. In some instances, dispensing of the one or more control agents and / or components of the reaction composition may occur periodically. In such embodiments, sensor measurement data may be used to ensure the chemical

[0129] IPTS / 2OO163O13.1 and / or physical characteristics of the reaction composition 105 are as desired. However, dispensing of the one or more control agents and / or components of the reaction composition, and more specifically the outputting of one or more control signals by the control unit to control the dispensers, may be independent of any specific sensor measurement. (The latter method of maintaining the reaction composition 105 may be based on known rates of consumption of components of the reaction composition or on known variation over time of pH or molecular oxygen concentration, for example.) In yet further embodiments, dispensing of the one or more agents and / or components of the reaction composition, and more specifically the outputting of one or more control signals by the control unit, may be directly dependent on one or more measured characteristics of the reaction composition 105. Similarly, the outputting of one or more control signals by the control unit to control dispensing of the one or more control agents and / or components of the reaction composition may be dependent on a measured sensor signal indicative of a change in a measured characteristic of the reaction composition 105. Combinations of some of these different methods may also be advantageous, for example using dispensing of agents and / or components for maintenance of the reaction composition 105 over shorter time intervals without use of sensor measurements, combined with adjustments being made based on regular sensor measurements made at longer time intervals.

[0130] In some instances, it may be beneficial to control the environmental conditions in which the system 100 is implemented, and in particular in which the surface polymers are formed. For example, this may help to reduce contaminants and other impurities contaminating the reaction composition 105 and / or the substrate 102. Non-limiting examples of contaminants and impurities may include bulk polymers or metals. Similarly, controlling environmental conditions such as, but not limited to, pressure, temperature, humidity, and / or inert atmosphere, may be beneficial to the process for forming surface polymers. To achieve this, in some embodiments, system 100 may be implemented in an environmentally controlled chamber. For example, the aforementioned containers may sit within one or more environmentally controlled chambers. In some embodiments all of the containers may sit within one or more chambers. In some embodiments a subset of the containers may sit within one or more chambers. For example, it is envisaged that in some embodiments the polymerization initiator container may sit within a chamber, whilst the reaction composition container 104, may sit outside a chamber. Similarly, in some embodiments it is envisaged that cleaning of the substrate prior to polymerization initiator formation may also occur

[0131] IPTS / 2OO163O13.1 in an environmentally controlled chamber, in which case the associated cleaning agent container also could sit within an environmentally controlled chamber.

[0132] The substrate displacement device 103 may relate to any device capable of transporting the substrate from one container to another container. For example, the substrate displacement device 103 may relate to a mechanical device. In particular, it is envisaged that the substrate displacement device 103 may comprise any one of: a conveyor system; a programmable mechanical arm or arms; and / or a roll-to-roll processor / mechanism.

[0133] A conveyor system as used herein may refer to a mechanical system that is used to move a material, such as the substrate, which in embodiments may be in a substrate holder on its own or with other substrates, from one process container to another, typically comprising a movable conveyor, powered by a drive system and having a series of rollers or pulleys that support and guide the belt. In use, the substrate may be placed on the conveyor which passes the substrate through the one or more containers comprised in the system. In this way, as the conveyor is powered, the substrate is passed through the component(s) held by each container within the system. Furthermore, in some embodiments the containers are enclosures in which the reaction composition, or other appropriate wet chemistry, is uniformly applied over the substrate using spray nozzles.

[0134] In some instances, a programmable mechanical arm, such as a robotic arm, may be used to transport the substrate, which may be in a holder as described above. The programmable mechanical arm, in embodiments, has the capability to move substrate holders horizontally and vertically in and out of containers and from container to container. The programmable mechanical arm may be equipped with gripping devices comprising suction devices, enabling handling of larger substrates. Such gripping device is, e.g., disclosed in WO 2019 / 114893.

[0135] A roll-to-roll processor or mechanism may be particularly beneficial for use where the substrate may be flexible and elongated, such as a cable, wire, foil, sheet or any other elongated flexible substrate. Fig. 5 illustrates such an embodiment, in which the substrate displacement device relates to a roll-to-roll processor 118, comprising a sending roll 121, a receiving roll 122 and a plurality of rollers 120. At least some of the rollers 120 and the receiving roll 122 are driven, thereby enabling a flexible elongated substrate 123 to be passed from the sending roll 121 through the reaction composition 105 in container 104 to the receiving roll 122. The roll-to-roll mechanism can be utilized as a replacement to the substrate displacement device 103 in Fig. 4 when elongated flexible substrates are being processed. In some embodiments, the substrate may be masked in certain areas to form surface polymers only from unmasked polymerization initiator. In some embodiments, polymerization initiator sites may only be attached at certain portion(s) on the substrate as described above. In some instances, only the portion(s) of the substrate is immersed into the reaction composition to form surface polymers on the poition(s) of the substrate being in contact with the reaction composition. In some embodiments, forming surface polymers on portion(s) of the substrate may be a combination of masking and bringing only the desired portion(s) of the substrate in contact with the reaction composition. The substrate displacement device or another type of substrate displace device may be suited for carrying out the specific contact between the substrate and the reaction composition.

[0136] In some instances, at least one of the plurality of containers may comprise an annealing oven for annealing the formed surface polymers. In a similar manner as described previously, the substrate displacement device 103 may be configured to transport the substrate with the formed surface polymers to the annealing oven 109 and to bring the substrate with surface polymers into position for annealing. The annealing oven is equipped with a heating device for annealing the formed surface polymers and the gas environment 111 in the oven may be controlled as needed - for example, to avoid oxidation by using only non-oxidizing gases.

[0137] According to some instances, a system 100 for forming surface polymers on a substrate may comprise: a reaction composition container containing a reaction composition, said reaction composition comprising: a monomer, a catalyst and a ligand forming a catalyst / ligand complex, a catalyst activator, and a solvent, and a substrate displacement device for bringing at least a portion of a polymerization initiator-modified substrate, or a portion of a substrate of polymer molecules into contact with the reaction composition in the reaction composition container for a controlled time, wherein the controlled time is sufficient for surface polymers of a specified average dry film thickness to be formed on the portion of the polymerization initiator-modified substrate. Furthermore, the substrate displacement device may comprise any one of: a conveyor system, a programmable mechanical arm, or a roll-to-roll mechanism. Furthermore, the system may comprise a polymerization initiator container containing a polymerization initiator agent, wherein the substrate displacement device is configured to bring the portion of the substrate for attachment of polymerization initiators into contact with the polymerization initiator agent to form

[0138] IPTS / 2OO163O13.1 polymerization initiators at the substrate surface, prior to bringing the portion of the polymerization initiator-modified substrate into contact with the reaction composition. Furthermore, the system may comprise one or more cleaning containers, the cleaning containers containing cleaning agents, wherein the substrate displacement device is configured to bring the portion of the polymerization initiator-modified substrate into contact with the cleaning agent prior to, or subsequent to, bringing the portion of the polymerization initiator-modified substrate into contact with the reaction composition, or the substrate displacement device is configured to bring the portion of substrate into contact with the cleaning agent prior to, or subsequent to, bringing the portion of the substrate into contact with the polymerization initiator. Furthermore, extra containers may be added as needed for rinsing, etc. between processes. The substrate displacement device may be one or more robots or a conveyor system with the capability to move substrates horizontally and vertically in and out of containers and from container to container. In some embodiments, system 100 may include one or more containers holding a chemistry for pre-wetting the substrate 105 prior to bringing the substrate 105 into contact with the reaction composition 105 in the reaction composition container 104. The pre-wetting chemistry may essentially correspond to the reaction composition 105, however, without the catalyst activator, for example, to pre-wet the surface but not induce polymerization reaction. In some embodiments, the pre-wetting chemistry may include one or more components to enhance pre-wetting of the substrate 102, for example, a composition of solvent differing from the reaction composition 105, or a pre -wetting agent with a specific pH. In some instances, system 100 may comprise more than one pre-wetting container for wetting the substate prior to or subsequent to any step of the process (or method) running on system 100.

[0139] In some instances, each container of system 100 may include flow control devices, such as, for example, circulation pumps, flow guidance grids, filters, and / or mechanical stirring means. The flow control devices may facilitate distribution of the chemistry in a container around the substrate 102, and may, in some cases, be useful for filtering off potential contaminants.

[0140] Aspects and embodiments of the disclosure are further illustrated by the following, non-limiting examples.

[0141] IPTS / 2OO163O13.1 Examples

[0142] List of chemicals used:

[0143] Throughout the examples, Dl-water refers to tap water deionized using the deionizing equipment Silhorko with M22-F softening plant, RO Bl -2 Reverse Osmosis plant and Silex 2BS mixed bed plant. The Dl-water has a conductivity of <0.5 pS / cm, indicating an ultrapure quality with very low presence of ions, below 0. 1 mg / L. The quality of the Dl-water was confirmed at least weekly.

[0144] Silicon wafer substrates (Si), Test CZ-Si wafer, 4 inch, thickness = 525 ± 25 pm, (100), p-type (Boron), were purchased from MicroChemicals GmbH (r = 5.08 cm) and cut into l / 4th of a wafer. Acetone (>99%) was purchased from Chemsolute.

[0145] Isopropanol (iPrOH) (99%) was purchased from Chemsolute.

[0146] Methanol (MeOH) (99%) was purchased from Chemsolute.

[0147] Ammonia (25% p. a) was purchased from Chemsolute.

[0148] ABC clean A200 was purchased from ABC-Clean ApS.

[0149] / MChloromethyljphenyltrimethoxysilane (CPTMS) (95%) was purchased from Gelest. Tris(2-pyridylmethyl)amine (TPMA) (98%) was purchased from Tokyo Chemical Industry.

[0150] Tris [2-(dimethylamino)ethyl] amine (Me6TREN) (>98%) was purchased from abcr or Alfa Aesar.

[0151] Ruthenium(III) chloride hydrate (RuC13) was purchased from Sigma Aldrich (CAS no 14898-67- 0, lot no MKCT 8564)

[0152] Methyl methacrylate (MMA) (99 %, 30 ppm MEHQ inhibitor) was purchased from Sigma Aldrich (lot no. STBK8834).

[0153] Glycidyl methacrylate (GMA) (> 97 %) was purchased from Sigma Aldrich.

[0154] Methyl acrylate (MA) (<100%) was purchased from Merck Life Science ApS

[0155] Sodium ascorbate (NaAsc) (98%) was purchased from Sigma Aldrich.

[0156] Dichloromethane (DCM) (min 99.9%) was purchased from Chemsolute.

[0157] Dimethylformamide (DMF) (99.9%) was purchased from Chemsolute.

[0158] Dimethyl sulfoxide (DMSO) (99.8%) was purchased from Chemsolute.

[0159] Catalyst M: Me6TREN (76 pL), Dl-water (15.924 mL), and Cu(II) (324 mg / L, obtained from a solid copper source by stirring or otherwise mixing prior to mixture with ligand and Dl-water).

[0160] IPTS / 2OO163O13.1 List of equipment used in the Examples:

[0161] “Big sonicator” refers to an ULTRASONIC CLEANER PROCLEAN 28.0 from Ulsonix (40 kHz, 480 W).

[0162] “Sonicator” refers toto a Bandelin Sonorex Super RK100 sonicator (35 kHz ultrasound frequency, 80 W nominal ultrasonic power).

[0163] “Vacuum oven” refers to a Faithful Vacuum Drying Oven-DZ-BCII.

[0164] “Oven” refers to a Binder model FD 56.

[0165] Ellipsometry was measured on a J. A. Woollam M-2000 Ellipsometer. This instrument was set to measure between 10 points on each substrate, unless otherwise indicated. Each point was analyzed using a Cauchy model providing a thickness and a Mean Square Error (MSE), the latter referring to the goodness of the fit. Thicknesses are thus given as the average of all measured points on the substrate (average dry film thickness). Unless specifically stated otherwise, 10 data points were obtained on each substrate. Standard deviation is the standard deviation based on the entirety of the measured thicknesses. The standard deviation is an estimate of the homogeneity of surface polymers formed. To obtain detailed datasets of surface polymer thickness from which lateral maps of surface polymer average dry film thickness can be produced, the ellipsometer instrument can be equipped with focusing optics (J. A. Woollam), reducing the beam spot size (the measured area) from 300 pm x 710 pm to 30 pm x 71 pm at a 65-degree angle of incidence. The much smaller beam size enables measurement of many more points on a substrate, enabling a higher resolution of the surface polymer average dry film thickness.

[0166] Example 1

[0167] Precleaning of substrates prior to deposition of polymerization initiators

[0168] Substrates were precleaned prior to attachment of polymerization initiators. Substrates were generally *4 of a whole Si wafer. The total number of substrates subjected to precleaning may vary (specific number of substrates are indicated in the subsequent examples).

[0169] Racks containing the Si substrates were placed in isopropanol (iPrOH) and sonicated for 5 minutes in a big sonicator. Then, the substrates mounted in the racks were placed in an oven at 80°C for 15 minutes. Thereafter, the racks holding the substrates were transferred to a 5:1 : 1 DL water / NH4OH / H2O2 solution at temperatures between 70°C and 75°C and sonicated for 10 minutes. Next, the rack containing the substrates was flushed under a running tap of Dl-water and transferred to a Dl-water container and sonicated for 5 minutes. Finally, the rack holding the

[0170] IPTS / 2OO163O13.1 substrates was transferred to an iPrOH-containing container and sonicated for 5 minutes, before being dried in an oven at 80°C for 15 minutes.

[0171] Example 2

[0172] Deposition of polymerization initiator

[0173] The example illustrates a procedure for attaching polymerization initiators to a substrate (in this case Si substrate).

[0174] Silicon wafer (Si) substrates, pre-cleaned as described in Example 1, were used for surface initiator-modification with CPTMS polymerization initiators using a chemical vapor deposition method: The substrates were placed in a rack and placed in a vacuum oven with 16 vials of 100 pL CPTMS (polymerization initiator liquid) at approximately 100°C for 30 minutes. The gauge pressure was lowered to -0.99 bar, whereby the CPTMS evaporated, and the substrates were left for 30 minutes in the vapor. Thereafter, the substrates were removed and left at ambient temperature and ambient pressure for 24 h to anneal the silane (CPTMS) polymerization initiator layer.

[0175] Ellipsometry measurements before and after the polymerization initiator deposition did not show significantly different surface layer thickness, indicating the formation of a thin layer CPTMS polymerization initiator layer. Thus, the layer thickness from the CPTMS initiator molecule is not expected to contribute in a significant way to the surface polymer average dry film thickness in subsequent surface polymer formations.

[0176] Example 3

[0177] General method for assessing the rate of surface polymer formation

[0178] This example illustrates a general procedure for assessing the rate at which surface polymers are formed on a substrate with time. This procedure described in this Example was used in subsequent Examples.

[0179] Silicon wafer substrates were pre-cleaned as described in Example 1 , and CPTMS polymerization initiator-modified as described in Example 2. All substrates were then immersed at the same time in reaction composition comprising components for the surface polymerization (specified in the following Examples). Substrates were individually recovered from the reaction composition according to the following procedure: at minute 0, defined as 5 minutes after addition of (a solution of) catalyst activator (NaAsc), all substrates were immersed into the reaction composition. At certain “timestamps”, typically at 2, 5, 7.5, 10, 20, and 40 minutes following minute 0, unless specified otherwise, one substrate was withdrawn from the reaction composition, immediately subjected to a rinsing and drying processes, comprising sonication in Dl-water for 5 minutes, followed by sonication in acetone for 5 minutes, and air drying in ambient conditions (temperature, pressure) for at least a few minutes. Withdrawal of substrates at different timestamps allows assessment of surface polymer formation (propagation) as a function of time.

[0180] Following post-polymerization cleaning and drying, the average dry film thicknesses (li) of the formed (collapsed) surface polymers were determined by ellipsometry. For each substrate, the average dry film thicknesses (in nm) were plotted against time (in minutes) at which the substrate was recovered. It is to be understood that the average dry film thickness (Ji) is directly proportional to the molecular weight by number average (Mn) as a result of the following equation: where, o is the grafting density of the polymer chains, AA is Avogadro’s number and p is the bulk density of the polymer.

[0181] In visualizing ellipsometry data this way, the rate of surface polymer formation can be evaluated as a function of time. From here, the “rate” of a given reaction composition is referred to as the average dry film thickness of surface polymers which were obtained as a function of time.

[0182] Example 4

[0183] Ru-catalvzed surface polymer formation with TPMA ligand and MMA monomer

[0184] In this example, the Ru-catalyzed surface polymer formation from CPTMS polymerization initiator-modified Si wafer substrates were shown.

[0185] A surface polymer formation experiment was performed as described in Example 3, with polymerization times 1 hour, and 20 hours, respectively.

[0186] The reaction composition for surface polymer formation was prepared as follows: To a Container C, 100.6 mg RuCh, 330.9 mg TPMA (Batch no CPW296), 26 mL Dl-water and 26 mL MeOH were mixed and sonicated for 5 minutes. To a 500 mL measuring cylinder, the content of Container

[0187] IPTS / 2OO163O13.1 C was added and diluted to total volume of 448 mL using Dl-water. The content of Container C was transferred to a glass container (Container A). 410 mL MeOH and 75 mL MMA were added to Container A. In a separate container (Container B), a solution of NaAsc (3999 mg in 15 mL DL water) was prepared. The content of Container B was poured into Container A (reaction container), and the reaction composition was left to react for 5 minutes to activate the catalyst / ligand complex between Ru and TPMA.

[0188] 2 CPTMS-initiator-modified substrates (substrate Si, initiator CPTMS) pre-cleaned as described in Example 1 and subjected to initiator-modification as described in Example 2 were placed in of the reaction container and one substrate was withdrawn at a certain time to conduct a rate experiment as described in Example 3 (time 0 = 5 minutes after activation of the complex between Ru and TPMA). After cleaning, the substrates were dried in an oven at 80°C (atmospheric conditions) for 30 seconds. Below, the average dry film thicknesses obtained at each time of withdrawal from the reaction container are reported in Table 1.

[0189] Table 1. Average dry film thicknesses for Ru-catalyzed surface polymer formation.

[0190] As can be seen from Table 1, the ruthenium catalyst was able to catalyze the formation of surface polymers from CPTMS polymerization initiators present on the surface of the substrate. It is noted that the rate of surface polymer formation may be slow for some applications, but the inventors speculate that polymerization conditions could possibly be manipulated to speed up the reaction if desired.

[0191] Example 5

[0192] Ru-catalyzed surface polymer formation with TPMA ligand and MMA monomer

[0193] In this example, the surface polymer formation using Ru as catalyst and TPMA as ligand was shown.

[0194] A surface polymer formation experiment was performed as described in Example 3, with the polymerization times 2, 4, 5 and 6.5, respectively.

[0195] IPTS / 2OO163O13.1 The reaction composition was prepared as follows: To a Container C, 100.2 mg RuCh, 332.7 mg TPMA (batch no EMP389), 16 mL Dl-water and 16 mL MeOH were mixed and sonicated for 5 minutes. To a 500 mL measuring cylinder, the content of Container C was added and diluted to total volume of 484 mL using Dl-water. The content of Container C was transferred to a glass container (Container A). 426 mL MeOH and 75 mL MMA were added to Container A. In a separate container (Container B), a solution of NaAsc (4005 mg in 15 mL Dl-water) was prepared. The content of Container B was poured into Container A (reaction container) and the reaction composition was left to react for 5 minutes to activate the catalyst / ligand complex (Ru / TPMA).

[0196] 6 CPTMS-initiator-modified substrates (substratelA Si wafer, initiator CPTMS), pre-cleaned as described in Example 1 and subjected to initiator-modification as described in Example 2 were placed in the reaction container and one substrate was withdrawn at a certain time to conduct a rate experiment as described in Example 3 (time 0 = 5 minutes after activation of complex between Ru and TPMS). An additional cleaning step was added to remove bulk polymer residue on the Si substrates following polymerization: all substrates were sonicated 2 times for 5 minutes in DCM before being dried in an oven at 80°C (atmospheric pressure and ambient air) for 30 seconds. Thereafter, the substrates were considered dry and could be subjected to ellipsometry. Below, the average dry film thicknesses obtained are reported in Table 2.

[0197] Table 2. Average dry film thicknesses for Ru-catalyzed surface polymer formation.

[0198] Table 2 indicates that surface polymer may be formed. The rate of surface polymer growth appears to proceed slowly which may indeed be desired for some applications. Indeed, very short surface polymers may be desired for some applications. The inventors, however, speculate that polymerization conditions could possibly be manipulated to alter the rate of surface polymer formation, if desired.

[0199] IPTS / 2OO163O13.1 Example 6

[0200] Ru-catalyzed surface polymer formation with TPMA ligand and MMA monomer in iPrQH

[0201] In this example, the formation of surface polymers using Ru as catalyst was shown using an alternative alcohol (iPrOH) in the solvent system.

[0202] A surface polymer formation experiment was performed as described in Example 3, with polymerization times of 2, 20 and 24 h, respectively.

[0203] The reaction composition was prepared as follows: To a Container C, 100.2 mg RuCL, 331.9 mg TPMA (batch no EMP389), 16 mL Dl-water and 16 mb iPrOH were mixed and sonicated for 25 minutes. To a 500 mL measuring cylinder, the content of Container C was added and diluted to total volume of 468 mL using Dl-water. The content of Container C was transferred to a glass container (Container A) containing 410 mL iPrOH and 75 mL MMA. In a separate container (Container B), a solution of NaAsc (4006 mg in 15 mL Dl-water) was prepared. The content of Container B was poured into Container A (reaction container), and the reaction composition was left to react 5 minutes to activate the catalyst / ligand complex (Ru / TPMA).

[0204] 3 CPTMS-initiator-modified substrates (substrate 1 / 4 Si wafer, initiator CPTMS), pre-cleaned as described in Example 1 and subjected to initiator-modification as described in Example 2 were placed in the reaction container, and one substrate was withdrawn at a certain time to conduct a rate experiment as described in Example 3 (time 0 = 5 minutes after activation of catalyst-ligand complex). An additional cleaning step was added to remove bulk polymer residue on the Si substrates: all substrates were sonicated for 5 minutes in DCM, before being dried in an oven at 80°C (atmospheric pressure and ambient air) for 30 seconds. Below, the average dry film thicknesses obtained at each time of withdrawal from the reaction container are reported in Table 3.

[0205] Table 3. Average dry film thicknesses for Ru-catalyzed surface polymer formation.

[0206] IPTS / 2OO163O13.1 As can be seen from Table 3, by applying a different solvent species (DI-water / iPrOH) the formation of surface polymers appears to proceed slowly producing surface polymer with lower thickness, which may indeed be desired for certain applications. The inventors, however, speculate that reaction conditions could possibly be manipulated to alter the rate of surface polymer formation, if desired.

[0207] Example 7

[0208] Ru-catalvzed surface formation with TPMA ligand and MMA monomer with reduced amount

[0209] In this example the formation of surface polymers using Ru as catalyst was shown using lower catalyst concentration is presented. This reduces the amount of ruthenium significantly which reduces the process cost significantly.

[0210] The general method for preparing the surface polymer forming liquid was prepared as follows:

[0211] To a Container C, RuCh (amount see Table 4), TPMA ligand (amount see Table 4) (batch no EMP389), 16 mL Dl-water and 16 mL MeOH were mixed and sonicated for 5 minutes. To a 500 mL measuring cylinder, the content of Container C was added and diluted to total volume of 468 mL using Dl-water. The content of Container C was transferred to a glass container (Container A) containing 410 mL MeOH. Container A was sonicated for 5 min to remove air bubbles. 75 mL MMA was added, and Container A was sealed with a septum and flushed with argon gas for 15 minutes. In a separate container (Container B), a solution of NaAsc (amount see Table 4 in 15 mL Dl-water) was prepared. Container B was sealed with a septum and flushed with argon gas.

[0212] CPTMS -initiator-modi tied substrates (substrate 1 / 4 Si wafer, initiator CPTMS subjected to initiator-modification as described in Example 2 were placed in the reaction container. The container was sealed with a lid equipped with a septum. The reaction container was flushed with argon gas.

[0213] When a solution / container is flushed with gas it is implied that the container is sealed with a septum equipped with two needles, one used to flush with gas (“flushing needle”), one used as a vent to allow gas to exit (“vent needle”). It is expected that after a given time the combination of gas and venting leads to a replacement of the atmosphere in the container with the flushing gas. To ensure an argon atmosphere during the entire process, the liquid was transferred as follows:

[0214] A double-ended cannula was placed in the septum of Container A and in the septum of container B. In Container B the one end of the double-ended cannula was submersed into the liquid reaching the bottom. By removing the “vent needle” in the septum of container B and the gas “flushing needle” from Container A, the liquid is transferred from Container B to Container A. After Container B was completely emptied into Container A, the double-ended cannula was removed from the system and flushing with Argon gas in Container A was resumed. The system was left for 5 minutes to activate the catalyst / ligand complex (Ru / TPMA) before a double-ended cannula was used to transfer the content of Container A to the reaction container. Once the content of Container A was fully transferred to the reaction container, the gas flushing system was removed and replaced with an argon gas filled balloon.

[0215] After being left overnight (19 - 24 h) the reaction container was opened, and the substrates were removed and cleaned from precipitate polymer by flushing in acetone. After cleaning the substrates were further cleaned by sonication in Dl-water for 5 min then sonication in acetone for 5 minutes. After sonication the substrates were left to dry until no visible solvent residues were visible on the substrate. After cleaning and drying, the Si substrates were subjected to ellipsometry to measure the average dry film thickness (using 36 points) of the formed (collapsed) surface polymers, reported in Table 5.

[0216] The above-described method was repeated 3 times (“Replica 1”, “Replica 2”, and “Replica 3”).

[0217] Table 4. Amounts of solids used in the reaction composition for surface polymerization for 3 different surface polymerizations. The surface polymerization time is shown for each surface polymerization.

[0218] IPTS / 2OO163O13.1 In Table 5, the average dry film thickness of the formed (collapsed) surface polymers is reported. The average dry film thickness of the surface polymer calculated on the basis of the substrates were: 298 nm (average substrates 1, 2, and 4, polymerization time 19 h), 344 nm (substrate 1, polymerization time 22 h) and 371 (average substrates 1, 2, 3, and 4, polymerization time 24 h).

[0219] Table 5. Average dry film thicknesses for Ru-catalyzed surface polymer formation for each polymerization (Replica 1, Replica 2, and Replica 3).

[0220] Surprisingly, even with a low amount of Ru catalyst the inventors were able to replicate and reproduce the higher average dry film thicknesses shown in Example 4. The lower amount of Ru catalyst offers a beneficial reduction in production costs.

[0221] Example 8

[0222] Polymerization rate of a Ru-catalyzed surface polymer formation with TPMA ligand and MMA monomer with reduced catalyst amount

[0223] In this example the formation of surface polymers using Ru as catalyst was shown using lower catalyst concentration (Example 7) is investigated in a “rate experiment” (see Example 3). Following the rate of the polymerization the inventors were able to determine the polymerization kinetics of the reduced Ru catalyzed surface polymer formation.

[0224] The general method for preparing the reaction composition prepared as follows: To a Container C, 10.5 mg RuCE (amount see Table 4), 330.5 mg TPMA ligand (amount see Table 4) (batch no EMP389), 16 mL Dl-water and 16 mL MeOH were mixed and sonicated for 5 minutes. To a 500 mL measuring cylinder, the content of Container C was added and diluted to total volume of 468 mL using Dl-water. The content of Container C was transferred to a glass container (Container A) containing 410 mL MeOH. Container A was sonicated for 5 min to remove air bubbles. 75 mL MMA was added, and Container A was sealed with a septum and flushed with argon gas for 15

[0225] IPTS / 2OO163O13.1 minutes. In a separate container (Container B), a solution of NaAsc (3998.4 mg NaAsc in 15 mL Dl-water) was prepared. Container B was sealed with a septum and flushed with argon gas.

[0226] 6 CPTMS-initiator-modified substrates (substrate 1 / 4 Si wafer, initiator CPTMS subjected to initiator-modification as described in Example 2) were placed in individual reaction containers. The containers were sealed with a lid equipped with a septum. The reaction containers were flushed with argon gas from Container A.

[0227] When a solution / container is flushed with gas it is implied that the container is sealed with a septum equipped with two needles, one used to flush with gas (“flushing needle’’), one used as a vent to allow gas to exit (“vent needle’’). It is expected that after a given time the combination of gas and venting leads to a replacement of the atmosphere in the container with the flushing gas.

[0228] To ensure an argon atmosphere during the entire process, the liquid was transferred as follows: A double-ended cannula was placed in the septum of Container A and in the septum of one of the reaction containers. In Container A the one end of the double-ended cannula was submersed into the liquid reaching the bottom. By removing the “vent needle” in the septum of Container A and the gas “flushing needle” in reaction container, the liquid is transferred from Container A to the reaction container. As such, 100 mL of the surface polymer forming liquid were transferred to each of the reaction containers. After each reaction container was filled, the flushing of argon gas continued. A 2 mL syringe was flushed with argon gas and used to transfer 1.5 mL of the solution from Container B to 5 of the 6 reaction containers, to activate the reaction composition. The last reaction container was left un-activated as a reference. This reference was included to verify that in the time before the activation of the reaction composition, no reaction took place on the substrate. After preparing the reaction composition, the gas flushing system was removed and replaced with an argon gas filled balloon.

[0229] As described in Example 3 a rate experiment was conducted by removing substrates from the reaction containers at different time intervals (0.5, 1, 3, 5 and 24 hours), and the substrates were cleaned from any precipitate polymer by flushing in acetone. After cleaning, the substrates were further cleaned by sonication in Dl-water for 5 minutes, followed by sonication in acetone for 5 minutes. After sonication, the substrates were left to dry until no visible solvent residues were visible on the substrates. After cleaning and drying, the Si substrates were subjected to ellipsometry to measure the average dry film thickness (using 36 points) of the formed (collapsed) surface polymers, reported in Table 6.

[0230] Table 6. Average dry film thicknesses for Ru-catalyzed surface polymer formation for each polymerization time.

[0231] ^Reference

[0232] In Table 6, the obtained average dry film thicknesses are shown. Initially (polymerization time 0.5 and 1 hour, respectively), the reaction composition did not seem to be fully activated for surface polymer formation due to the lower average dry film thicknesses obtained (a thickness of 2 nm was considered equal to the thickness of the initiator layer). Interestingly, between 1 and 3 hours, the surface polymerization seems to proceed rather fast producing surface polymers of a thickness of 83 nm after 3 hours and, more surprising, 283 nm after 5 hours. As seen in Example 6, after 24 hours, this Ru reduced polymerization yields a thickness of 320 nm. It is noted that average dry film thickness of the Reference was determined to 2.8 nm which equals the polymerization initiator layer, and, thus, no surface polymerization took place.

[0233] These results are quite extraordinary as it seems that relatively high surface polymer thicknesses (300 nm) may be achieved within a relatively short polymerization time (5 hours). Furthermore, within 1 to 3 hours polymerization time, surface polymer of an average dry film thickness of 2-80 nm may be achieved.

[0234] Example 9

[0235] Ru-catalyzed surface polymer formation with TPMA ligand and MMA monomer with reduced catalyst amount and reduced reaction composition volume

[0236] IPTS / 2OO163O13.1 In this example, the successful formation of surface polymers using reduced amount of Ru catalyst and reduced volume of reaction composition. Thus, surface polymer production costs may significantly be reduced. This further reduces the amount of ruthenium significantly which reduces the process cost significantly.

[0237] The surface polymer formation was performed as follows: 3 CPTMS-initiator-modified substrates (substrate 1 / 4 Si wafer, initiator CPTMS subjected to initiator-modification as described in Example 2) were placed in a reaction container. To a Container C, 10.6 RuCE, 330.9 mg TPMA ligand (batch no FPA 264), 16 mL Dl-water and 16 mL MeOH were mixed and sonicated for 5 minutes. To a 500 mL measuring cylinder, the content of Container C was added and diluted to total volume of 468 mL using Dl-water. The content of Container C was transferred to a glass container (Container A) containing 410 mL MeOH. Container A was sonicated for 1 minute to remove air bubbles. To a measuring cylinder 660 mL of the content of Container A was transferred and 50 mL MMA monomer was added. The content of the measuring cylinder was transferred to the reaction container. The container was sealed with a lid equipped with a septum. The reaction container was flushed with argon gas for 15 minutes. In a separate container (Container B), a solution of NaAsc (4013.9 mg NaAsc in 15 mL Dl-water) was prepared. Container B was sealed with a septum and flushed with argon gas. 10.5 mL of the liquid was transferred from Container B to the reaction container to activate the reaction composition for surface polymer formation. The flushing of the argon gas continued to ensure complete mixing. After the activation of the reaction composition, the gas flushing system was removed and replaced with an argon gas filled balloon. After being left overnight (21 h), the reaction container was opened, and the substrates were removed and cleaned from any precipitate polymer by flushing in acetone. After flushing, the substrates were further cleaned by sonication in Dl-water for 5 minutes, then followed by sonication in acetone for 5 minutes. Additional cleaning was done by sonication in acetone for 5 minutes, sonication in DMSO for 5 minutes, sonication in DMF for 5 minutes and finally by flushing with acetone. After sonication, the substrates were left to dry in ambient conditions (ambient temperature, ambient pressure) until no visible solvent residues were observed on the substrates. After cleaning and drying, the Si substrates were subjected to ellipsometry to measure the average dry film thickness (using 36 points) of the formed (collapsed) surface polymers. The average dry film thickness of the formed surface polymers across the 3 substrates were found to be 728 ± 38 nm. Amazingly, surface polymers having an average dry film thickness of more than 700 nm were achieved. The inventors note that leaving the substrates to rest in the un-activated reaction mixture might be beneficial to the surface-initiated polymerization. The thorough cleaning of the substrates following surface polymer formation confirms the surface polymer formation (not deposited polymer formed in solution). Polymers formed in solution and deposited would surely have been cleaned off by rinsing in DMSO and DMF, whereas surface polymers covalently bound via polymerization initiators on the substrate surface would not.

[0238] The inventors note a possible advantage in letting the substrates rest in the non-activated reaction composition. In Example 8, the inventors found that no surface polymer was formed using a nonactivated reaction composition after 24 hours (of attempted surface polymerization time), however, in the present case, it seems as if a rest in the unactivated reaction composition, followed by activation of the reaction composition led to increased surface polymerization. The inventors hypothesize that during the rest time, vacant sites of the Ru / ligand complex interact with the surface initiators preparing the surface for polymerization prior to the activation. This is illustrated in Fig. 7.

[0239] Example 10

[0240] Ru-catalyzed surface polymer formation with TPMA ligand and MA monomer

[0241] For this surface polymer formation, MA monomer was used. Overall, the structure of the MA monomer may be similar to the MMA monomer, however, the acrylate moiety of the MA monomer is known to be of lower reactivity generally.

[0242] The surface polymer formation was performed as follows: 3 CPTMS-initiator-modified substrates (substrate 1 / 4 Si wafer, initiator CPTMS subjected to initiator-modification as described in Example 2) were placed in a reaction container. To a Container C, 10.2, 329.2 mg TPMA ligand (batch no FPA 264), 16 mF Dl-water and 16 mF MeOH were mixed and sonicated for 5 minutes. To a 500 mF measuring cylinder, the content of Container C was added and diluted to total volume of 468 mF using Dl-water. The content of Container C was transferred to a glass container (Container A) containing 410 mF MeOH. Container A was sonicated for 1 minute to remove air bubbles. To a measuring cylinder, 660 mF of the content of Container A was transferred and 50 mF MA monomer was added. The content of the measuring cylinder was transferred to the reaction container. The container was sealed with a lid equipped with a septum. The reaction container was

[0243] IPTS / 2OO163O13.1 flushed with argon gas for 15 minutes. In a separate container (Container B), a solution of NaAsc (4008.0 mg NaAsc in 15 mL DI- water) was prepared. Container B was sealed with a septum and flushed with argon gas. 10.5 mL of the liquid was transferred from Container B to the reaction container to activate the reaction composition for surface polymer formation. The flushing of the argon gas continued to ensure complete mixing. After the activation of the surface polymer forming liquid, the gas flushing system was removed and replaced with an argon gas filled balloon. After being left overnight (21 h) the reaction container was opened, and the substrates were removed and cleaned from any precipitate polymer by flushing in acetone. After flushing, the substrates were further cleaned by sonication in Dl-water for 5 minutes, followed by sonication in acetone for 5 minutes. Additional cleaning was done by sonication in acetone for 5 minutes, sonication in DMSO for 5 minutes, and flushing with acetone. The substrates were left to dry at ambient conditions (ambient temperature, ambient pressure) until no visible solvent residues were observed on the substrates. After cleaning and drying, the Si substrates were subjected to ellipsometry to measure the average dry film thickness (using 36 points) of the formed (collapsed) surface polymers. The average dry film thickness of the formed surface polymers across the 3 substrates were found to be 5 + / - 0.7 nm.

[0244] Surprisingly, the Ru-catalyzed surface-initiated polymerization was able to polymerize the low reactivity MA monomer.

[0245] Example 11

[0246] Ru-catalvzed surface polymer formation with TPMA ligand and GMA monomer

[0247] In this example the formation of surface polymers of GMA (PGMA) was investigated. PGMA surface polymer is overall similar to PMMA surface polymers in structure, however, with a glycidyl group in lieu of the methyl group.

[0248] The surface polymers were formed as follows: 3 CPTMS-initiator-modified substrates (substrate 1 / 4 Si wafer, initiator CPTMS subjected to initiator-modification as described in Example 2) were placed in a reaction container. To a Container C, 9.8 RuCh, 330.4 mg TPMA ligand (batch no FPA 264), 16 mL Dl-water and 16 mL MeOH were mixed and sonicated for 5 minutes. To a 500 mL measuring cylinder, the content of Container C was added and diluted to total volume of 468 mL using Dl-water. The content of Container C was transferred to a glass container (Container A) containing 410 mL MeOH. Container A was sonicated for 1 minute to remove air bubbles. 75 mL GMA monomer was added. The content of the Container A was transferred to the reaction container. The container was sealed with a lid equipped with a septum. The reaction container was flushed with argon gas for 15 minutes. In a separate container (Container B), a solution of NaAsc (4000.0 mg NaAsc in 15 mL Dl-water) was prepared. Container B was sealed with a septum and flushed with argon gas. The NaAsc solution was transferred from Container B to the reaction container to activate the reaction composition. The flushing of the argon gas continued to ensure complete mixing. After the activation of the surface polymer forming liquid, the gas flushing system was removed and replaced with an argon gas filled balloon. After being left overnight (21 hours), the reaction container was opened, and the substrates were removed and cleaned from any precipitate polymer by flushing in acetone. After flushing, the substrates were further cleaned by sonication in Dl-water for 5 minutes, followed by sonication in acetone for 5 minutes. Additional cleaning was performed by sonication in acetone for 5 minutes, sonication in DMSO for 5 minutes, 2 times sonication in DMF for 5 minutes each, and by flushing with acetone. After sonication, the substrates were left to dry at ambient conditions (ambient temperature, ambient pressure) until no visible solvent residues were observed on the substrates. After cleaning and drying, the Si substrates were subjected to ellipsometry to measure the average dry film thickness (using 36 points) of the formed (collapsed) surface polymers. The average dry film thickness of the formed surface polymers across the 3 substrates were found to be 207 ± 11 nm.

[0249] A surface polymer of approximately 200 nm was formed using the Ru catalyst. This demonstrates the usefulness of the Ru catalyst in surface polymer formations.

[0250] Example 12

[0251] Ru-catalyzed initiation of polymerization

[0252] In this example, the inventors investigate the recognition that the Ru catalyst may be able to initiate polymerization from a polymer on a surface of a substrate. For this experiment, a substrate with a previously formed PMMA surface polymer was used. The substrate had been subjected to PMMA surface polymer formation using Cu / MeeTREN (MeeTREN = tris 2-dimethylamino)ethylamine) as catalyst / ligand for 40 minutes, thus, indicating end-termination of viable ends on the PMMA surface polymer.

[0253] The PMMA surface polymer was formed as follows: To a glass container (Container A), Dl-water (726 mL), Catalyst M (23.4 mL), EtOH (615 mL) and MMA monomer (112.5 mL) were added.

[0254] IPTS / 2OO163O13.1 In a separate container (Container B) a solution of NaAsc (6003.5 mg in 22.5 mL Dl-water) was prepared. The content of Container B was poured into Container A, and the reaction composition was left for 5 minutes to activate the reaction composition for surface polymer formation. 30 CPTMS -initiator-modified substrates (substrate 1 / 4 Si wafer, initiator CPTMS subjected to initiator-modification as described in Example 2) were placed in a reaction container and the reaction composition of Container A was poured into the reaction container. The substrate was left for 40 minutes polymerization time in the reaction composition and was subsequently cleaned by sonication for 5 minutes in Dl-water, followed by sonication in acetone for 5 minutes, before being left to dry at ambient conditions (ambient temperature, ambient pressure). After cleaning and drying, the Si substrates were subjected to ellipsometry to measure the average dry film thickness (using 36 points) of the formed surface polymers. The average dry film thickness of the formed surface polymers was found to be 63 ±1 nm.

[0255] The polymerization procedure used for initiating the surface polymerization was as follows: To a Container C, 10.5 mg RuCh, 331.7 mg TPMA ligand (batch no EMP389), 16 mL Dl-water, and 16 mL MeOH were mixed and sonicated for 5 minutes. To a 500 mL measuring cylinder, the content of Container C was added and diluted to total volume of 468 mL using Dl-water. The content of Container C was transferred to a glass container (Container A) containing 410 mL MeOH. Container A was sonicated for 5 minutes to remove air bubbles. 75 mL MMA was added, and Container A was sealed with a septum and flushed with argon gas for 15 minutes. In a separate container (Container B), a solution of NaAsc (4002.7 mg in 15 mL Dl-water) was prepared. Container B was sealed with a septum and flushed with argon gas. A double-ended cannula was placed in the septum of Container A and in the septum of Container B. In Container B the one end of the double-ended cannula was submersed into the liquid reaching the bottom. By removing the “vent needle” in the septum of Container B and the gas “flushing needle” from Container A, the liquid is transferred from Container B to Container A. After Container B was completely emptied into Container A, the double-ended cannula was removed from the system and flushing with Argon gas in Container A was resumed. Once the content of Container A was fully transferred to the reaction container containing the one PMMA surface polymer substrate and one CPTMS -initiator- modified substrates (substrate 1 / 4 Si wafer, initiator CPTMS subjected to initiator-modification as described in Example 2), the gas flushing system was removed and replaced with an argon gas filled balloon. The CPTMS substrate was included as control substrate. The reaction container was sealed with a lid equipped with a septum. The reaction container was flushed with argon gas. After

[0256] IPTS / 2OO163O13.1 being left overnight (22 h), the reaction container was opened, and the substrates were removed and cleaned from any precipitate polymer (not surface-bound polymer) by flushing in acetone. After this cleaning, the substrates were further cleaned by sonication in Dl-water for 5 minutes, followed by sonication in acetone for 5 minutes. The substrates were left to dry at ambient conditions (ambient temperature, ambient pressure) until no visible solvent residues were visible on the substrates. After cleaning and drying, the Si substrates were subjected to ellipsometry to measure the average dry film thickness (using 36 points) of the formed (collapsed) surface polymers. The average dry film thickness of the formed surface polymers are reported in Table 7.

[0257] Table 7. Average dry film thicknesses of the substrate with PMMA surface polymers following the second (initiation) polymerization and the CPTMS polymerization initiator-modified control substrate.

[0258] Table 7 clearly shows that the Ru catalyst was able to initiate surface polymer formation. The average dry film thickness of the surface polymer formed on the CPTMS -modified substrate and on the previously formed PMMA substrate is separated by 83 nm which is close to 63 nm, equaling the average dry film thickness of the PMMA substrate before the initiation surface polymerization, taking into account the standard deviations.

[0259] As a control experiment, the inventors investigated whether Cu-catalyzed surface polymerization could initiate polymerization. As a control experiment, the inventors investigated whether Cu- catalyzed surface polymerization could initiate polymerization.

[0260] The following procedure was used: To a glass container (Container A), Dl-water (410 mL), Catalyst M (16 mL), EtOH (410 mL), and MMA monomer (75 mL) were added. In a separate container (Container B), a solution of NaAsc (4000 mg in 22.5 mL Dl-water) was prepared. The content of Container B was poured into Container A, and the reaction composition was left for 5 minutes to activate the reaction composition for surface polymer formation. Prior to the mixing of the reaction composition, 6 Si substrates were pre -cleaned by undergoing a process where racks containing the substrates were placed in an aqueous solution of ammonia (15 vol% DI-water / 85 vol% ammonia, commercially available, 25% p. a. from Chemsolute, cleaning liquid) and

[0261] IPTS / 2OO163O13.1 sonicated for 10 minutes. Then, the substrates were flushed with Dl-water and sonicated in DI- water for 10 minutes. Thereafter, the racks containing the substrates were transferred to a 5% solution of ABC clean A200 (from ABC-Clean ApS) and sonicated for 10 minutes at in a Bandelin Sonorex Super RK100 sonicator (35 kHz ultrasound frequency, 80 W nominal ultrasonic power). This step was followed by flushing the substrates in Dl-water and sonicating the substrates in DI- water for 5 minutes with the previously described equipment. Finally, the substrates were flushed with acetone (>99%, Chemsolute), and left to dry at room temperature. The newly cleaned 6 Si substrates were used for surface modification with CPTMS polymerization initiators using a chemical vapor deposition method as follows: The substrates were placed in a rack and placed in a vacuum oven (Faithful Vacuum Drying Oven-DZ-BCII) with 16 vials of 100 pL CPTMS (polymerization initiator liquid, commercially available, 95% grade from Gelest) at approximately 45°C for 150 minutes. The gauge pressure was lowered to -1.0 bar, whereby the CPTMS evaporated, and the substrates were left for 150 minutes. Thereafter, the substrates were removed and placed in an oven (Binder model FD 56) at approximately 80°C for 5 minutes to anneal the silane layer. 6 CPTMS-initiator-modified substrates were placed in a reaction container, and the reaction composition of Container A was poured into the reaction container. The substrates were withdrawn at a certain time to conduct a rate experiment as described in Example 3 and were subsequently cleaned by sonication for 5 minutes in Dl-water. Subsequently, the substrate was sonicated for 5 minutes in acetone, before being left to dry at ambient conditions (ambient temperature, ambient pressure). After cleaning and drying, the substrate was subjected to ellipsometry to measure the average dry film thickness of the formed PMMA surface polymer (see Table 8).

[0262] Next, the PMMA surface polymer substrates were subjected to a second polymer formation according to the following procedure: To a glass container (Container A), Dl-water (727 mL), Catalyst M (23 mL), EtOH (620 mL) and MMA monomer (112 mL) were added. In a separate container (Container B), a solution of NaAsc (6000 mg in 23 mL Dl-water) was prepared. The content of Container B was poured into Container A, and the reaction composition was left for 5 minutes to activate the reaction composition for surface polymer formation. The 6 PMMA surface polymer substrates were placed in a reaction container, and the reaction composition of Container A was poured into the reaction container. The substrates were left for 10 minutes in the reaction composition and were subsequently cleaned by sonication for 5 minutes in Dl-water, followed by sonication for 5 minutes in acetone, before being left to dry at ambient conditions (ambient

[0263] IPTS / 2OO163O13.1 temperature, ambient pressure). After cleaning and drying, the substrates were subjected to ellipsometry to measure the average dry film thickness of any formed second PMMA surface polymer (see Table 8).

[0264] Table 8. Average dry film thicknesses following first PMMA surface polymer formation and second PMMA polymerization. In the first PMMA polymerization, a substrate was withdrawn at times 2, 5, 7.5, 10, 20, and 40 minutes, respectively. In the second PMMA polymerization, each of the substrates from the first PMMA polymerization was subjected to 10 minutes of PMMA polymerization.

[0265] This experiment led the inventors to conclude the following: 1) longer polymerization times (20 minutes and above) do end-terminate the surface polymer chains (polymer molecules) (no significant increase in average dry film thickness), thus, there are no viable chain-ends which can undergo further polymerization with the Cu catalyst. 2) shorter polymerization times (up to 20 minutes) do not end-terminate surface polymer chains (polymer molecules), and a block polymer of PMMA may be formed by the second PMMA polymerization with the Cu catalyst. 3) The Ru catalyst was indeed able to initiate the polymer formation from otherwise end-terminated surface polymers with reference to the results given in Table 7. Here, the Ru catalyst initiated surface polymer formation with an average dry film thickness of approximately 300 nm.

[0266] IPTS / 2OO163O13.1 This points towards a surprisingly unique property of the Ru catalyst. Cu-catalyzed surface polymerization and polymerizations in solution tend to reach a plateau for the molecular size (Mn) of polymer synthesized within a certain polymerization time. For formation of surface polymers, this corresponds to a halt in the development of the propagating surface polymer as a function of time. As evident from Table 8, where the increase in average dry film thicknesses of Cu-catalyzed PMMA polymerization as a function of time is reported, the polymer formation reaches a plateau after approximately 20 minutes (most likely due to end-termination of viable ends). This may be interpreted as an overactivation of polymerization which results in loss of viable chain-ends. A loss in viable chain-ends minimizes the polymerization initiation potential, meaning that additional surface polymer formation cannot be achieved. With reference to Table 8, this end-termination behavior was observed for the attempted second PMMA polymerization on substrates with a first polymerization time above 20 minutes. It was surprising to the inventors that the Ru catalyst was able to initiate polymerizations despite end-termination.

[0267] This is a mechanism contrary to the polymerization mechanism of the Cu / ligand complex used in Cu-catalyzed polymerizations. In these, the Cu / ligand complex only interact with an alkyl halide (the polymerization initiator) and facilitates an atomic transfer of the halide from the alkyl to the Cu / ligand complex, leaving a free alkyl radical that reacts with the monomer thereby instigating the polymerization reaction. The reverse of this reaction, the deactivation (formation of deactivating spices), restores the alkyl halide and the Cu / ligand complex. Leaving the free radical to react with a monomer is a well-known technique, however, as seen in this Example polymerization using Cu as catalyst does not continue for long (see Table 8, polymerization times above approximately 20 minutes), before the propagating surface polymer comes to a halt resulting in surface polymer molecules with average dry film thicknesses in the 100 nm range.

[0268] The inventors hypothesize that, once activated, the Ru / ligand complex may coordinate with double-bond-containing and / or C-H-bond-containing organic molecules. The inventors propose that the Ru / ligand complex may interact with such bonds through the vacant sites. Thus, interaction with carbon hydrate bond (C-H) may involve an initial abstraction of a proton (H), leaving the carbon free to be coordinated into a vacant site of the Ru / ligand complex resulting in the Ru / ligand complex being bound to the PMMA surface polymer with one vacant site, ready to accept a monomer C=C bond in the Ru-catalyzed polymerization. Another possible coordination interaction may take place between a carbonyl bonds (C=O) on the PMMA surface polymer and a

[0269] IPTS / 2OO163O13.1 vacant site of the Ru / ligand complex, whereafter the remaining vacant site may be able to react / coordinate with a nearby C-H bond, followed by the C=O bond being expelled, resulting in the Ru / ligand complex being bound to the PMMA surface polymer with one vacant site ready to accept monomer in the Ru-catalyzed polymerization.

[0270] IPTS / 2OO163O13.1 List of reference numerals

[0271] 100 System

[0272] 102 Substrate

[0273] 103 Substrate displacement device

[0274] 104 Reaction composition container

[0275] 105 Reaction composition

[0276] 106 Container

[0277] 107 Polymerization initiator chemistry

[0278] 109 Annealing oven

[0279] 114 Cleaning container

[0280] 116 Cleaning agent / device

[0281] 118 Roll-to-roll processor

[0282] 120 Roller

[0283] 121 Sending roll

[0284] 122 Receiving roll

[0285] 123 Flexible elongated substrate

[0286] 200 Ru / ligand complex

[0287] 201 Ligand

[0288] 202 Ruthenium

[0289] 203 Vacant site on ruthenium

[0290] 204 Vacant site on ruthenium

[0291] 300 Ru / ligand complex

[0292] 301 Ligand

[0293] 302 Ruthenium

[0294] 303 Polymerization initiator

[0295] 304 Vacant site

[0296] 400 Ru / ligand complex

[0297] 401 Ligand

[0298] 402 Ruthenium

[0299] 403 C-C double bond (C=C) or C-0 double bond (C=O)

[0300] 404 Polymerization initiator

[0301] 500 Ru / ligand complex

[0302] 501 Ligand 502 Ruthenium

[0303] 503 Polymer molecule of a substrate

[0304] 504 Vacant site

[0305] 600 Ru / ligand complex 601 Ligand

[0306] 602 Ruthenium

[0307] 603 Polymer molecule of a substrate

[0308] 604 C-C double bond (C=C) or C-0 double bond (C=O)

[0309] IPTS / 2OO163O13.1

Claims

1. Claims1. A method for forming surface polymers on a substrate comprising: providing a substrate, wherein the substrate has polymerization initiators on at least a portion of a surface of the substrate, or wherein the substrate has polymer molecules on at least a portion of a surface of the substrate, exposing the substrate to a reaction composition comprising: a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, a catalyst activator, and a solvent, to form surface polymers on the substrate.

2. A method according to claim 1, wherein the Ru compound is a Ru(III) or a Ru(II) compound.

3. A method according to claim 1 or 2, wherein the Ru compound is RuCR, RuCk, RuCh hydrate, or RuCh hydrate.

4. A method according to any one of claims 1 to 3, wherein the solvent is aqueous.

5. A method according to claim 4, wherein the solvent is a combination of methanol and water, ethanol and water, or isopropanol and water.

6. A method according to any one of claims 1 to 5, wherein the catalyst activator is selected from sodium ascorbate (NaAsc), ascorbic acid (Asc), hydrazine, hydrazine hydrate, sodium thiosulfate, sodium sulfite, sodium dithionite, glucose with GOX, and / or pyrogallic acid.

7. A method according to claim 1, wherein the reaction composition comprises a buffer and / or a zwitterionic buffer.IPTS / 2OO163O13.

18. A method according to claim 7, wherein the buffer is selected from carbonate buffer, glycine buffer, citrate buffer, phosphate buffer, acetate buffer, ammonium buffer (ammonium chloride / am- monia), formate buffer, and / or sodium ascorbate / ascorbic acid buffer.

9. A method according to claim 7, wherein the zwitterionic buffer is a Good's buffer selected from MES, PIPES, MOPS, HEPES, CHES, CAPSO and / or CAPS.

10. A method according to claim 1, wherein the ligand is a nitrogen-containing ligand.

11. A method according to claim 10, wherein the ligand is heterocyclic nitrogen-containing ligand.

12. A method according to claim 10 or 11, wherein the ligand is selected from N,N,N’,N",N,’,- pentamethyldiethylene -triamine (PMDETA), tris[2-(dimethylamino)ethyl]amine (MeeTREN), tris(2-aminoethyl)amine (TREN), tris(2-pyridylmethyl)amine (TPMA), 1,1,4,7,10,10- hexamethyltriethylenetetramine (HMTETA), tetramethylethylenediamine (TMEDA), 1,4,8,11- tetramethyl-1,4,8,11 -tetraazacyclotetradecane (Me4Cyclam), 2,2 ’-bi pyridyl (BiPy), and / or pyridine.

13. A method according to claim 1, wherein the monomer is selected from methyl methacrylate (MMA), methacrylate (MA), allyl methacrylate (AMA), glycidyl methacrylate (GMA), 2- hydroxyethyl methacrylate (HEMA), N-hydroxyethyl acrylamide (HEAM), 2-hydroxyethyl acrylate (HEA), tert-butyl acrylate (tBA), styrene, vinylimidazole (VI), N-vinylpyrrolidone, and vinylpyridine (VPY).

14. A method for forming a surface polymer on a substrate comprising: providing a substrate, exposing at least a portion of the surface of the substrate to a polymerization initiator, and exposing the substrate to a reaction composition comprising: a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, a catalyst activator, and a solvent.IPTS / 2OO163O13.

115. A method according to claim 14, further comprising exposing the substrate having surface polymers on at least a portion of a surface of the substrate to a reaction composition comprising: a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, a catalyst activator, and a solvent.

16. A method according to claim 14 or 15, wherein the Ru compound is a Ru(III) compound or a Ru(II) compound.

17. A method according to claim 16, wherein the Ru compound is RuCh. RuCh, RuCh hydrate, or RuCh hydrate18. A method according to any one of claim 14 to 16, wherein the solvent is aqueous.

19. A method according to claim 18, wherein the solvent is a combination of methanol and water, ethanol and water, or isopropanol and water.

20. A method according to claim 15, wherein the catalyst activator is selected from sodium ascorbate (NaAsc), ascorbic acid (Asc), hydrazine, hydrazine hydrate, sodium thiosulfate, sodium sulfite, sodium dithionite, glucose with GOX, and / or pyrogallic acid.

21. A method according to claim 15, wherein the reaction composition comprises a buffer and / or a zwitterionic buffer.

22. A method according to claim 21, wherein the buffer is selected from carbonate buffer, glycine buffer, citrate buffer, phosphate buffer, acetate buffer, ammonium buffer (ammonium chloride / am- monia), formate buffer, and / or sodium ascorbate / ascorbic acid buffer.

23. A method according to claim 21, wherein the zwitterionic buffer is a Good’s buffer selected from MES, PIPES, MOPS, HEPES, CHES, CAPSO and / or CAPS.

24. A method according to claim 15, wherein the ligand is a nitrogen-containing ligand.IPTS / 2OO163O13.

125. A method according to claim 24, wherein the ligand is a heterocyclic nitrogen-containing ligand.

26. A method according to claim 24 or 25, wherein the ligand is selected from N,N,N’,N",N"’- pentamethyldiethylene-triamine (PMDETA), tris[2-(dimethylamino)ethyl]amine (MeeTREN), tris(2-aminoethyl)amine (TREN), tris(2-pyridylmethyl)amine (TPMA), 1,1,4,7,10,10- hexamethyltriethylenetetramine (HMTETA), tetramethylethylenediamine (TMEDA), 1,4,8,11- tetramethyl-l,4,8,l l-tetraazacyclotetradecane (Me4Cyclam), 2,2’ -bipyridyl (BiPy), and / or pyridine.

27. A method according to claim 15, wherein the monomer is selected from methyl methacrylate (MMA), methacrylate (MA), allyl methacrylate (AMA), glycidyl methacrylate (GMA), 2- hydroxyethyl methacrylate (HEMA), N-hydroxyethyl acrylamide (HEAM), 2-hydroxyethyl acrylate (HEA), tert-butyl acrylate (tBA), styrene, vinylimidazole (VI), N-vinylpyrrolidone, and vinylpyridine (VPY).

28. A system for forming surface polymers on a substrate, the system comprising: a reaction composition container containing a reaction composition, said reaction composition comprising: a monomer, a catalyst / ligand complex formed from a Ru compound and a ligand, and a catalyst activator, and a substrate displacement device for bringing at least a portion of a polymerization initiator- modified substrate into contact with the reaction composition in the reaction composition container for a controlled time, wherein the controlled time is sufficient for surface polymers to be formed on the portion of the polymerization initiator-modified substrate.

29. A system according to claim 28, wherein the substrate displacement device comprises any one of: a conveyor system, a programmable mechanical arm, ora roll-to-roll mechanism.

30. A system according to claim 28 or 29, further comprising a polymerization initiator container containing a polymerization initiator agent, wherein the substrate displacement device is configured to bring the portion of the substrate for attachment of polymerization initiators into contact with the polymerization initiator agent to form polymerization initiators at the substrate surface, prior to bringing the portion of the polymerization initiator-modified substrate into contact with the reaction composition.

31. A system according to claim 20, wherein the polymerization initiator container is a vacuum oven.

32. A system according to any one of claims 28 to 31 comprising one or more cleaning containers, each cleaning container containing a cleaning agent, wherein the substrate displacement device is configured to bring the portion of the polymerization initiator-modified substrate into contact with the cleaning agent prior to, or subsequent to, bringing the portion of the polymerization initiator- modified substrate into contact with the reaction composition, and / or the substrate displacement device is configured to bring the substrate into contact with the cleaning agent prior to, or subsequent to, bringing the portion of the substrate into contact with the polymerization initiator or the reaction composition.

33. A system according to claim 28, further comprising one or more containers for pre-wetting the at least a portion of the substrate prior to bringing the at least a portion of the substrate into contact with the reaction composition.

34. A system according to claim 28, further comprising a reaction composition management system.

35. A system according to claim 34, wherein the reaction composition management system comprises one or more sensors in relation to the reaction composition container.

36. A system according to claim 28, further comprising one or more flow control devices.IPTS / 2OO163O13.

137. A system according to claim 36, wherein the one or more flow control devices are selected from circulation pumps, flow guidance grids, filters, and / or mechanical stirring means.

38. A system according to any one of claims 28 to 37, further comprising a heating device for annealing the substrate prior to, or subsequent to, bringing the at least a portion of the polymerization initiator-modified substrate into contact with the reaction composition.

39. A polymer formed on at least a portion of at least a surface of a substrate by a method according to any one of claims 1 to 27.IPTS / 2OO163O13.1

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