Self-healing composition of matter and methods of preparation and use thereof

Abstract

A self-healing composition of matter is provided that includes a covalent adaptive network having a primer layer covalently tethered to a surface and a coated polymer crosslinked with the primer layer through a reversible covalent linkage. Also provided is a method of preparing the composition, a method of preparing a self-healing surface by applying the composition to a surface, use of the composition for preparing a scratch-resistant, solvent-resistant, anti-fouling, or anti-corrosion coating layer, a coating material, coated surface, or article of manufacture including the composition, and a method of increasing scratch resistance, corrosion resistance, solvent resistance, or adhesion resistance of a surface by applying to a substrate the composition.

Description

SELF-HEALING COMPOSITION OF MATTER AND METHODS OF PREPARATION ANDUSE THEREOFCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority of U.S. Provisional Application Serial No. 63 / 649,541, filed on May 20, 2024, and entitled “RAPID SELF-HEALING OF ROBUST SURFACE-TETHERED COVALENT ADAPTABLE COATINGS”, the entirety of which is incorporated herein by reference.FIELD OF THE INVENTION

[0002] The present invention generally relates to self-healing compositions of matter, coatings based on such compositions of matter, and methods of preparation and use thereof.BACKGROUND

[0003] Polymeric coatings are used widely to modify or preserve the functionality or aesthetics of a surface, such as without limitation by protecting it from harsh environments. To enable orthogonal functionality requirements, many commercial coatings include multiple layers, often combining a binding layer to assure durability with a topcoat to impart environmental resistance and longevity. However, the protective nature and performance of coatings can be compromised during use. Both during transport and service, the surface can be exposed to mechanical damage, environmental degradations (e.g., UV light, saline solutions, solvents), and microbial stressors, among others, resulting in wear, delamination, or loss of functionality and / or aesthetics.

[0004] Self-healing coatings can repair damage and recover material performance with minimal or no intervention. Beyond their relevance for introducing corrosion resistance to metals, self- healing coatings are of high relevance to healthcare, aerospace, construction, and electronics industries. However, the development of coating materials with self-healing capabilities is still in its infancy.SUMMARY OF THE DISCLOSURE

[0005] An aspect is a self-healing composition of matter as disclosed herein. The composition includes a covalent adaptive network, wherein the covalent adaptive network includes a primer layer covalently tethered to a surface and a coated polymer crosslinked with the primer layer through a reversible covalent linkage. In some embodiments, the coated polymer can include a spray-coated polymer. In some embodiments, the covalent adaptive network can include a vitrimer. In some embodiments, the primer layer or the coated polymer can include an acrylate / methacrylate polymer. In some embodiments, the primer layer or the coated polymer can include a terpolymer of 2-(acetoacetoxy)ethyl methacrylate (AAEMA or simply A), methyl methacrylate (MA or simply M), and n-butyl acrylate (nBA, nBuA, or simply B). In some embodiments, the primer layer or the coated polymer can include a bipolymer of AAEMA and n-hexyl methacrylate (HMA). In some embodiments, the primer layer or the coated polymer can include ethyl hexyl methacrylate. In some embodiments, the primer layer can include or be implemented as a polymer brush layer. In some embodiments, the reversible covalent linkage can include a vinylogous urethane group, a vinylogous urea group, a cyclohexenyl group, a 1,2,3-triazolium group, an ester group, a siloxane group, an olefin group, a disulfide group, a carbamate group, a trithiocarbonate group, an alkoxyamine group, an imine group, and / or the like. In some embodiments, the composition can be tethered to a substrate or wafer. In some embodiments, the composition can be used to create a self-healing coating layer on a surface of silica, glass, ceramic, polymer, resin, metal, metal alloy, and / or the like. The composition can be prepared using any method of preparation described in this disclosure.

[0006] Another aspect is a method of preparing the self-healing composition as disclosed herein that includes preparing a primer layer tethered to a surface and applying a polymer to the primer layer, wherein at least one portion of the polymer crosslinks with the primer layer through a reversible covalent linkage. In some embodiments, the polymer can be spray-coated. In some embodiments, preparing the primer layer can include immobilizing a chain transfer agent (CTA) onto the surface, such as without limitation through a reactive surface group (e.g., hydroxyl), and synthesizing the polymer brush layer using the immobilized CTA. In some embodiments, the CTA can include a dithioester, a dithiobenzoate, a dithiocarbamate, a trithiocarb onate, or a xanthate. In some embodiments, the CTA can include 4-cyano- 4[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid (CDTPA). In some embodiments, the polymer brush layer can be synthesized using surface-initiated polymerization, such as without limitation reversible addition-fragmentation chain transfer polymerization (RAFT) or surface- initiated photoinduced electron transfer-reversible addition-fragmentation chain transfer polymerization (SI-PET-RAFT). In some embodiments, the primer layer can be polymerized using a photocatalyst. In some embodiments, the photocatalyst can include a coordination complex, such as without limitation a substituted or unsubstituted zinc tetraphenylporphyrin (ZnTPP). In some embodiments, the photocatalyst can be illuminated using blue light, such as without limitation at a wavelength of 405 nm. In some embodiments, the polymer to be spray coated can be synthesized using free radical polymerization. In some embodiments, the free radical polymerization can be initiated using an initiator such as without limitation azobisisobutyronitrile (AIBN), 1,1’-azobi s(cy cl ohexanecarbonitrile) (ABCN), di- / -butyl peroxide (DTBP), benzoyl peroxide (BPO), methyl ethyl ketone peroxide (MEKP), acetone peroxide (APEX), a peroxydisulfate salt, a carbon halide, a benzenesulfonic acid ester, an alkyl sulfonium salt, 2,2’-azobis[2-(2-imidazolin-2- yl)propane] dihydrochloride, / -butyl hydroperoxide (TBHP), cumene hydroperoxide, dicumyl peroxide, ammonium persulfate (APS), and / or the like. In some embodiments, coating the polymer can include coating or spray-coating a solution of the polymer. In some embodiments, the solution to be coated or spray coated can further include a crosslinking agent such as without limitation tris(2- aminoethyl) amine (TREN) and / or m-xylylenedi amine. In some embodiments, the polymer or the solution of the polymer can be applied or spray coated using an airbrush spray jet. In some embodiments, the polymer or the solution of the polymer can be applied using a brush, roller, or applicator, or via drop-casting, spin-coating, dip-coating, etc.

[0007] Another aspect is a method of preparing a self-healing surface, the method including applying or tethering to a surface the composition described herein. In some embodiments, the method can further include drying or curing the composition to produce a coating layer.

[0008] Another aspect is use of the composition described herein for preparing a scratchresistant, solvent-resistant, anti-fouling, or anti-corrosion coating layer.

[0009] Another aspect is a coating material including the composition described herein.

[0010] Another aspect is a coated surface including a substrate and the composition described herein applied or tethered to the substrate.

[0011] Another aspect is an article of manufacture including the composition described herein.

[0012] Another aspect is a method of increasing scratch resistance, corrosion resistance, solvent resistance, or adhesion resistance of a surface, the method including applying or tethering to a substrate the composition described herein.

[0013] These and other aspects and features of nonlimiting embodiments of the present invention will become apparent to those skilled in the art upon review of the following description of specific nonlimiting embodiments of the invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] For the purpose of illustrating the invention, the drawings show aspects of one or more embodiments of the invention. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings.

[0015] FIG. 1 depicts a schematic illustration of how visible light-mediated surface-initiated polymerization is combined with a spray-coating approach to form surface-tethered covalently adaptable networks (CANs).

[0016] FIG. 2A depicts a schematic illustration describing the synthesis of polymer brushes via SI-PET-RAFT

[0017] FIG. 2B depicts exemplary data showing the evolution of polymer brush thickness as a function of irradiation time (lmax = 405 nm) for SI-PET -RAFT of AAEMA, MA, and nBA monomers.

[0018] FIG. 2C depicts an exemplary X-ray photoelectron spectrum of SiCE-tethered poly(AMB) brushes.

[0019] FIG. 2D depicts an exemplary image showing a water contact angle of SiCh-tethered poly(AMB) brushes measured using a goniometer.

[0020] FIG. 3A depicts an exemplary photograph of a spray-coated surface-tethered CAN on a SiCh wafer. The inset shows a schematic illustration of how the spray-coated polymer covalently crosslinks with the surface-tethered polymer brush. The grey and white spheres indicate TREN in its dynamic crosslinked and free reactive (-NH2) forms, respectively.

[0021] FIG. 3B depicts a schematic illustration describing the chemistry of the spray-coated polymer forming dynamic crosslinks with the polymer brush primer layer via addition of TREN. Shown are dynamic crosslinks, free reactive groups, associative exchange intermediates, and TREN- firee AAEMA units throughout the polymer matrix.

[0022] FIG. 3C depicts exemplary XPS spectra of the |~poly(AMB) brush primer layer only (bottom) and the spray-coated fdm that contains TREN (top), the structure of each of which is schematically illustrated in the insets.

[0023] FIG. 4A depicts an exemplary photograph of a surface-tethered covalently adaptable coating on a glass slide after being scratched with a razor blade.

[0024] FIG. 4B depicts an exemplary photograph of the same coating as shown in FIG. 4A after 35 s of self-healing at ~ l 70 °C.

[0025] FIG. 4C depicts exemplary data showing a temporal evolution of an incision healing over 60s as illustrated by contour plot renderings obtained as snapshots via optical profilometry at 160 °C.

[0026] FIG. 4D depicts exemplary line profdes from the optical profilometry data in FIG. 4C, showing substantially complete self-healing of an incision within a time span of 60 s.

[0027] FIG. 5A depicts exemplary data showing a temporal evolution of the width and depth of scratches, normalized to the initial scratch dimensions, upon healing at different temperatures. The lines (solid = depth, dashed = width) are the best fits of an exponential decay to a single characteristic time, T.

[0028] FIG. 5B depicts exemplary data showing a temperature dependence of T for the self- healing of scratches. The dashed line corresponds to a fit using the Vogel-Fulcher-Tamman (VFT) equation.

[0029] FIG. 6 depicts exemplary schematic illustrations and optical micrographs showing sheardelamination for a physisorbed CAN upon scratching with a razorblade. In comparison, the covalently tethered CAN shows no such shear delamination.

[0030] FIG. 7 depicts an exemplary1H-NMR spectrum of a poly(AAEMA-co-MA-co-nBA) terpolymer synthesized via free radical polymerization. Azobisisobutyronitrile (AIBN) was used as the initiator.

[0031] FIG. 8 depicts an exemplary gel permeation chromatogram of a poly(AAEM A-co-M A- co-nBA) terpolymer synthesized via free radical polymerization. Azobisisobutyronitrile (AIBN) was used as the initiator.

[0032] FIG. 9 depicts exemplary differential scanning calorimetry (DSC) data for poly(AMB) / TREN CANs at a scan rate of 20 °C / min on heating, illustrating a glass transition temperature of Tg= 42 °C.

[0033] FIG. 10 depicts exemplary dynamic mechanical analysis (DMA) data for poly(AMB) / TREN CANs at a scan rate of 3 °C / min, with a 0.5% axial strain applied, under a frequency of 1 Hz.

[0034] FIG. 11 A depicts exemplary stress relaxation curves from a 0.3% step strain for the terpolymer vitrimer at 110 °C, 120 °C, 130 °C, and 140 °C, respectively.

[0035] FIG. 1 IB depicts exemplary data showing an Arrhenius relation of stress relaxation for poly(AMB) / TREN CANs.

[0036] FIG. 12 depicts a schematic illustration describing the synthesis of poly(AAEMA-co- MA-co-nBA) polymer brushes from RAFT initiator-functionalized SiCE substrates. SiCE was initially activated using Piranha treatment to generate surface-bound hydroxyl groups. 4-cyano- 4[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid (CDTPA) was selected as the RAFT CTA initiator. SI-PET -RAFT was used to polymerize the three monomers, i.e., AAEMA, MA, and nBA, in DMSO, with zinc tetraphenylporphyrin (ZnTPP) (1 mg / mL) as a photocatalyst.

[0037] FIG. 13 depicts an exemplary high-resolution carbon Cis X-ray photoelectron spectrum of poly(AAEMA-co-MMA-co-nBA) polymer brushes and corresponding curve fits of three distinct carbon environments: R3C-CR3, R3C-O-RC=O, and O-RC=O.

[0038] FIG. 14A depicts a schematic illustration of the chemical structure of polymer brushes including a bipolymer of AAEMA and / / -hexyl methacrylate (HMA), i.e., poly(AAEMA-co-HMA), synthesized via Sl-PET-RAFT.

[0039] FIG. 14B depicts corresponding kinetics data of the poly(AAEMA-co-HMA) polymer brushes as shown in FIG. 14A, with polymer brush thickness plotted as a function of irradiation / reach on time.

[0040] FIG. 15 depicts an exemplary high-resolution carbon Cis X-ray photoelectron spectrum of poly(AAEMA-co-MA-co-nBA) polymer brushes that were spray coated with a solution of poly(AAEMA-co-MA-co-nBA) and TREN. The curve fits show three distinct carbon environments: R3C-CR3, C-(N,O), and O-RC=O.

[0041] FIG. 16A depicts an exemplary photograph of an unfunctionalized silicon wafer after synthesis of a vitrimer coating, curing, and Soxhlet extraction with dichloromethane at 40 °C for 24 h.

[0042] FIG. 16B depicts an exemplary photograph of a p(AMB) polymer brush-functionalized silicon wafer after synthesis of a vitrimer coating, curing, and Soxhlet extraction with di chloromethane at 40 °C for 24 h. Compared to FIG. 16A, the functionalized wafer in FIG. 16B demonstrates an improved solvent resistance via preservation of the coating after Soxhlet extraction.

[0043] FIGS. 17A-B depict exemplary screenshots directly from the Zeta-20 Optical Profilometer before and after self-healing at 130 °C for two minutes. Left: 13:37:09 on 25 July 2023. Right: 13:43:11 on 25 July 2023.

[0044] FIGS. 18A-C depict multiple exemplary snapshots of scratch profiles at various time intervals at 70 °C, 100 °C, and 120 °C, respectively.

[0045] FIG. 19A depicts exemplary healing kinetics of scratches as a function of time at 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C, and 130 °C, respectively.

[0046] FIG. 19B depicts exemplary data comparing small strain stress relaxation from a 0.3% strain in a rheometer (right axis) with the depth recovery of a scratch (left axis) at 130 °C. The scratches heal faster than the stress relaxes in the vitrimer.

[0047] FIG. 19C depicts exemplary data showing slow healing of scratch at ambient temperature.

[0048] FIG. 20 depicts an exemplary photograph of p(AMB) / TREN vitrimer coating on a polymer brush-functionalized substrate after heating to T > 200 °C. Self-healing was initially successful on this coating at a lower temperature, but as degradation of the coating worsened (evidenced by a change in color from clear to a brownish-green), scratches would only partially heal, if at all, or would leave scars.

[0049] FIG. 21 depicts an exemplary photograph illustrating the experimental spray-coating approach at a 10-cm spraying distance. 1.5 cm * 1.5 cm blue silicon wafers are the substrates visible on the cardboard; the upper wafer is unfunctionalized, whereas the lower wafer is functionalized with a ~p(AMB) polymer brush.

[0050] FIG. 22 depicts an exemplary photograph of p(AAEMA-co-HMA) (including 35 mol% AAEMA) crosslinked with TREN deposited (via drop coating) on p(AAEMA-co-HMA) polymer brush-functionalized silicon wafers. These samples successfully self-healed. The photograph shown is after a cycle of damage and autonomous recovery.

[0051] FIG. 23 depicts an exemplary photograph of p(AAEMA-co-HMA) polymer brush- functionalized silicon wafers with an attempt at blade coating the vitrimer on the surface.

[0052] FIG. 24 depicts an exemplary photograph of p(AMB) / TREN CANs on unfunctionalized glass (left) and p(AMB) polymer brush-functionalized glass (right) before and after self-healing.

[0053] The drawings are not necessarily to scale and can be illustrated by phantom lines, diagrammatic representations, and fragmentary views. In certain instances, details that are not necessary for an understanding of the embodiments or that render other details difficult to perceive may have been omitted.DETAILED DESCRIPTION

[0054] The incorporation of self-healing properties to repair scratches (or other minor damages) can potentially revolutionize the coating industry by increasing the service life, sustainability, and optical / aesthetic appearance of coated surfaces, and there is an unmet need for easy-to-apply and robust approaches to introduce self-healing capacities and to increase both the durability and the longevity of coatings. To meet such needs, both autonomous and non-autonomous healing mechanisms can be used. The former provides an inherent defect-filling mechanism by adding healing agents, while the latter requires external stimuli — most often heat and light — to accomplish surface repair. A common autonomous self-healing approach is based on imbedding microcapsules. These microcapsules can break when the coating is damaged and release healing agents which polymerize to repair the damage. The contents within these capsules can be formulated to repair thedamage via multi-component (i.e., monomer plus initiator) or single-component approaches (e.g., ambient thO-initiated polymerization, epoxy curing agents, or crosslinkable oils). While efficient, the microcapsules approach inherently requires appropriate tailoring of chemical / physical properties to allow for stability of the capsules during service but mechanical fracture when desired. Further challenges arise in distributing microcapsules evenly throughout the coating and / or assuring desired reactant ratios are met uniformly.

[0055] Alternatively, non-autonomous self-healing leverages recovery of chemical bonds, physical conformations, or non-covalent interaction in coating matrices. For this approach, external stimuli are required to provide sufficient activation energy for bond breakage / reformation. Either temperature or light can be used to modulate a dynamic exchange of covalent bonds or non-covalent interactions and impart self-healing properties. Common covalent bonding approaches include, but are not limited to, reversible cycloadditions (e.g., Diels-Alder reactions), exchange reactions (e.g., disulfides, siloxanes, vinylogous urethanes, etc.), or stable radical-mediated reshuffling reactions (e.g., trithiocarbonate exchange or dynamic alkoxyamine groups). For non-covalent interactions, hydrogen bonds, metal-ligand coordination, ionic interactions, and others have been used to engineer materials that can repair themselves (Lehn, J.-M., “ Supram olecular Chemistry — Scope and Perspectives Molecules, Supermolecules, and Molecular Devices (Nobel Lecture)”, Angew. Chem. Int. Ed, 1988; 27(1):89-112; Burattini, S. et al., “Supram olecular Polymer Based on Tweezer-Type 7t- 'll Stacking Interactions: Molecular Design for Healability and Enhanced Toughness”, Chem. Mat., 2011; 23(l):6-8; and Takahiro Kakuta, C. et al., “Preorganized Hydrogel: Self-Healing Properties of Supramol ecul ar Hydrogels Formed by Polymerization of Host-Guest-Monomers That Contain Cyclodextrins and Hydrophobic Guest Groups”, Ad. Mater. 2013; 25(20): 2849-2853).

[0056] Despite their increasing prevalence for macroscopic self-healing materials, the use of dynamic bonds to introduce self-healing capabilities into polymeric coatings remains in its infancy. For example, Ma et al. described ultra-thin (< 100 nm) superhydrophobic covalent adaptable network (CAN) films (thinner than 100 nm) that include polydimethylsiloxane network strands with dynamic boronic ester crosslinks (Ma, J. et al., “Ultra-Thin Self-Healing Vitrimer Coatings for Durable Hydrophobicity”, Nat. Comm., 2021 ; 12(1): 1-10). In this study, razor blade-induced scratches self-healed upon application of pressure at room temperature. In another example, Du Prez and co-workers described recyclable physisorbed CAN films based on polyamine curing agents and vinylogous urethanes vitrimers (Van Lijsebetten, F. et al., “Recyclable Vitrimer Epoxy Coatings for Durable Protection”, Eur. Polym. J., 2022; 176: 111426). Heat-driven restoration after scratching wasdemonstrated, which provided durable protection against corrosion. Han et al. described an epoxybased vitrimer coating that leveraged dynamic transesterification but showed incomplete healing (40% recovery within 10 minutes) at elevated temperatures (Han, J. et al., “A Catalyst-Free Epoxy Vitrimer System Based on Multifunctional Hyperbranched Polymer”, Macromol. 2018; 57(17):6789-6799). However, these intriguing approaches are based on physisorbed CANs, which, similar to irreversible epoxy-based covalent networks, can be prone to environmental damage and failure, especially through delamination or blistering near damaged regions. The nanometer-scale thickness of some examples avoids mass transport limitations in the healing of micron-scale defects, but these ultrathin coatings are difficult to implement practically for defect-free coatings. Moreover, these implementations generally provide only partial self-healing, where damage induces permanent minor defects even after self-healing. One additional challenge with most existing approaches for self-healing coatings is their focus on spin- or dip-coating approaches, which present limitations in their scalability or ability to coat complex topography.

[0057] To address these limitations, this disclosure describes a user-friendly (spray-)coating approach towards surface-tethered self-healing coatings. This approach addresses challenges with the robustness of self-healing coatings through inclusion of surface-tethered covalently adaptable networks. Surface-initiated polymerization can be combined with spray coating to deposit polymers, producing coatings with reversible crosslinks to the tethered chains. These robust coatings can be based on reversible vinylogous urethane bonds using 2-(acetoacetoxy)ethyl methacrylate (AAEMA)- based polymers and tris(2-aminoethyl) amine (TREN). Here, TREN can enable reversible covalent bonding between the spray-coated and surface-tethered polymers.

[0058] The approach described herein can use polymer brushes as a primer or anchor layer to tether the covalently adaptable networks to the surface of a substrate, thereby enhancing the kinetics of healing and improving the environmental robustness of the coating. Unexpectedly, it was found that such surface tethering plays an important role in a full recovery of the coatings upon self- healing. Without such surface tethering, the physisorbed covalently adaptable network coatings fail to self-heal completely, are labile to solvent, and exhibit shear delamination upon scratching.

[0059] The self-healing and robust coatings based on surface-tethered covalently adaptable networks are capable of autonomously repairing micron-scale incisions, either within seconds at elevated temperatures or steadily over extended periods of time under ambient conditions, while resisting solvent or shear delamination. Therefore, this approach towards durable covalently attached functional coatings provides opportunities for applications ranging from general anti-fouling andanti -corrosion coatings to specialty surface treatments, such as without limitation in improving scratch resistance of specialty optics and optical equipment.

[0060] To facilitate the understanding of this invention, a number of terms are defined below and throughout the disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control. The terminology herein is used to describe specific embodiments of the invention, but their usage does not limit the invention, except as outlined in the claims. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety.

[0061] It is to be understood that any aspect and / or element of any embodiment of the method(s) described herein or otherwise can be combined in any way to form additional embodiments of the method(s), all of which are within the scope of the method(s).

[0062] Where a process is described herein, those of ordinary skill in the art will appreciate that the process can operate without any user intervention. In another embodiment, the process includes some human intervention (e.g., a step is performed by or with the assistance of a human).

[0063] As used herein, including the claims, the phrase “at least some” means “one or more” and includes the case of only one. Thus, e.g., the phrase “at least some ABCs” means “one or more ABCs” and includes the case of only one ABC.

[0064] As used herein, including the claims, the term “at least one” should be understood as meaning “one or more” and therefore includes both embodiments that include one or multiple components. Furthermore, dependent claims that refer to independent claims that describe features with “at least one” have the same meaning, both when the feature is referred to as “the” and “the at least one”.

[0065] As used herein, the term “portion” means some or all. Therefore, for example, “a portion of X” can include some of “X” or all of “X”. In the context of a conversation, the term “portion” means some or all of the conversation.

[0066] As used herein, including the claims, the phrase “using” means “using at least” and is not exclusive. Thus, e.g., the phrase “using X” means “using at least X”. Unless specifically stated by use of the word “only”, the phrase “using X” does not mean “using only X”.

[0067] As used herein, including the claims, the phrase “based on” means “based in part on” or “based, at least in part, on” and is not exclusive. Thus, e.g., the phrase “based on factor X” means “based in part on factor X” or “based, at least in part, on factor X”. Unless specifically stated by use of the word “only”, the phrase “based on X” does not mean “based only on X”.

[0068] In general, as used herein, including the claims, unless the word “only” is specifically used in a phrase, it should not be read into that phrase.

[0069] It should be appreciated that the words “first”, “second”, and so on, in the description and claims, are used to distinguish or identify, and not to show a serial or numerical limitation.

[0070] Similarly, letter labels (e g., “(A)”, “(B)”, “(C)”, and so on, or “(a)”, “(b)”, and so on) and / or numbers (e.g., “(i)”, “(ii)”, and so on) are used to assist in readability and to help distinguish or identify, and are not intended to be otherwise limiting or to impose or imply any serial or numerical limitations or orderings. Similarly, words such as “particular”, “specific”, “certain”, and “given”, in the description and claims, if used, are to distinguish or identify, and are not intended to be otherwise limiting.

[0071] As used herein, including the claims, the terms “multiple” and “plurality” mean “two or more,” and include the case of “two”. Thus, e.g., the phrase “multiple ABCs” means “two or more ABCs” and includes “two ABCs”. Similarly, e.g., the phrase “multiple PQRs” means “two or more PQRs” and includes “two PQRs”.

[0072] The present invention also covers the exact terms, features, values, and ranges, etc., in case these terms, features, values, and ranges, etc., are used in conjunction with terms such as “about”, “around”, “generally”, “substantially”, “essentially”, “at least”, etc. Thus, e.g., “about 3” or “approximately 3” shall also cover exactly 3, and “substantially constant” shall also cover exactly constant.

[0073] As used herein, unless stated otherwise, the terms “about” or “approximately” refer to a value that is within 10% above or below the value being described.

[0074] As used herein, including the claims, singular forms of terms are to be construed as also including the plural form and vice versa, unless the context indicates otherwise. Thus, it should be noted that as used herein, the singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. In other words, terms such as “a”, “an”, and “the” are not intended to refer to only a singular entity but include the general class of which a specific example can be used for illustration.

[0075] Throughout the description and claims, the terms “comprise”, “including”, “having”, “contain”, and their variations should be understood as meaning “including but not limited to” and are not intended to exclude other components unless specifically so stated.

[0076] It will be appreciated that variations to the embodiments of the invention can be made while still falling within the scope of the invention. Alternative features serving the same, equivalent, or similar purpose can replace features disclosed in the specification, unless stated otherwise. Thus, unless stated otherwise, each feature disclosed represents one example of a generic series of equivalent or similar features.

[0077] Use of exemplary language, such as “for instance”, “such as”, “for example” (“e.g.,”), and the like, is merely intended to better illustrate the invention and does not indicate a limitation on the scope of the invention unless specifically so claimed.

[0078] While the invention has been described in connection with what is presently considered to be the most practical and embodiments thereof are further described in the examples below, it is to be understood that the invention is not to be limited to the disclosed embodiment but is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0079] The following description sets forth various examples along with specific details to provide a thorough understanding of claimed subject matter. It will be understood by those skilled in the art, however, that claimed subject matter can be practiced without one or more of the specific details disclosed herein. Further, in some circumstances, well-known methods, procedures, systems, and / or components have not been described in detail in order to avoid unnecessarily obscuring claimed subject matter. The illustrative embodiments described in the detailed description and claims are not meant to be limiting. Other embodiments can be utilized, and other changes can be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.Self-Healing Composition of Matter

[0080] An objective of the present disclosure is directed towards a self-healing composition of matter. As used herein, a “self-healing composition of matter” or “self-healing composition” is a chemical composition capable of repairing, reversing, or recovering from one or more defects or damages created therein or applied thereto. The composition includes a covalent adaptive network.As used herein, a “covalent adaptive network” or “CAN” is a type of polymer, polymer network, or polymer material that includes one or more dynamic chemical crosslinks through one or more exchangeable chemical bonds. Such chemical crosslinks can be efficiently and reliably exchanged between different positions, portions, or fragments of one or more polymer chains, and as a result, a macroscopic flow or displacement can be achieved without risking structural damage or permanent loss of material properties in the polymer.

[0081] Covalent adaptive networks can be further classified into two groups depending on their exchange mechanism. The first group of covalent adaptive networks make use of a dissociative crosslink exchange mechanism wherein chemical bonds are first broken and then formed again at another location. The second group of covalent adaptive network make use of associative bond exchanges between polymer chains, in which the original crosslink is only broken when a new covalent bond to another position has been formed or established.

[0082] As used herein, a “polymer” is a large molecule with repeating structural units connected to one another by covalent chemical bonds. The terms polymer and macromolecules are often used interchangeably. Accordingly, a chemical process for synthesizing a polymer is termed polymerization. In some embodiments, a polymer or polymer component described herein, such as without limitation a primer layer, a polymer brush, a (spray -)coated polymer, and / or the like, can be polymerized from monomers such as without limitation styrene (to form polystyrene), acrylate (to form polyacrylate), acrylamide (to form polyacrylamide), methacrylate (to form polymethacrylate), methacrylamide (to form polymethacrylamide), vinyl ester (to form polyvinyl ester), vinyl amide (to form polyvinyl amide), isocyanate and polyol (to form polyurethane), and / or the like. Additionally, and / or alternatively, a polymer can be prepared using reactions such as polyaddition, polycondensation, free radical polymerization, cationic polymerization, anionic polymerization, coordination polymerization, and / or the like.Vitrimer

[0083] In some embodiments, the covalent adaptive network can include a vitrimer. As used herein, a “vitrimer” is a type of thermally malleable polymer network that is capable of changing its topology through associative, thermally triggered exchange reactions and characterized by a gradual decrease in viscosity upon heating similar to vitreous silica. At higher temperatures, the viscosity of a vitrimer is essentially controlled by chemical exchange reactions, which results in a thermal viscosity decrease that follows the Arrhenius equation. Vitrimers are permanent networks with a substantially constant number of chemical bonds and a connectivity present at all temperatures.Primer Layer

[0084] The CAN includes a primer layer covalently tethered to a surface. As used herein, a “primer layer” is a layer of preparatory chemical(s) or material(s) applied to a surface before one or more subsequent steps of surface coating or treatment. A primer layer can increase adhesion of coating layer(s) to the surface bring treated, thereby improving the durability of the coating and / or providing additional protection to the surface underneath.

[0085] In some embodiments, the primer layer can include a homopolymer. As used herein, a “homopolymer” is a polymer derived from a single type of monomer. In some embodiments, the primer layer can include a copolymer. As used herein, a “copolymer” is a type of polymer derived from more than one type of monomers. Depending on the types of monomers involved, a copolymer can include a bipolymer (i.e., with two types of monomers), a terpolymer (i.e., with three types of monomers), a quaterpolymer (i.e., with four types of monomers), and / or the like. A copolymer can contain a specific ratio between different monomers, such as without limitation a 20:80 molar ratio for a bipolymer, a 10:80: 10 molar ratio for a terpolymer, and / or the like. Additionally, depending on the type of copolymerization being used, a copolymer can accordingly be categorized as an alternating copolymer, a random copolymer, a block copolymer, a stereoblock copolymer, a periodic copolymer, a gradient copolymer, a graft copolymer, a brush copolymer, a star copolymer, and / or the like.

[0086] In some embodiments, the primer layer can include a polymer brush layer. As used herein, a “polymer brush layer” or “polymer brush” is a layer of polymer chains tethered, grafted, or covalently linked or connected to a surface. As used herein, “tethering” or “grafting” refers to the act of attaching one chemical species to another though a chemical bond. A tethered or grafted chemical species can sometimes be referred to as a chemisorbed species instead. When compared to an intermolecular force (e.g., physisorption), a chemical bond is a much stronger type of interaction; therefore, a chemical bond imparts a higher binding affinity between a chemical species, e.g., a polymer chain, and its target, e.g., a surface, resulting in a more thermodynamically stable connection therebetween.

[0087] In some embodiments, the polymer brush layer can have a thickness of no greater than 300 nm. As nonlimiting examples, the polymer brush layer can have a thickness of no greater than 10 nm, no greater than 20 nm, no greater than 30 nm, no greater than 40 nm, no greater than 50 nm, no greater than 60 nm, no greater than 70 nm, no greater than 80 nm, no greater than 90 nm, no greater than 100 nm, no greater than 120 nm, no greater than 140 nm, no greater than 160 nm, nogreater than 180 nm, no greater than 200 nm, no greater than 220 nm, no greater than 240 nm, no greater than 260 nm, no greater than 280 nm, no greater than 300 nm, and / or the like.

[0088] In some embodiments, the polymer brush layer can have a thickness of at least 5 nm. As nonlimiting examples, the polymer brush layer can have a thickness of at least 10 nm, at least 20 nm, at least 30 nm, at least 40 nm, at least 50 nm, at least 60 nm, at least 70 nm, at least 80 nm, at least 90 nm, at least 100 nm, at least 120 nm, at least 140 nm, at least 160 nm, at least 180 nm, at least 200 nm, at least 220 nm, at least 240 nm, at least 260 nm, at least 280 nm, at least 300 nm, and / or the like.

[0089] In some embodiments, the polymer brush layer can have a thickness of at least 5 nm and no greater than 300 nm. As nonlimiting examples, the polymer brush layer can have a thickness of at least 5 nm and no greater than 10 nm, at least 10 nm and no greater than 20 nm, at least 20 nm and no greater than 30 nm, at least 30 nm and no greater than 40 nm, at least 40 nm and no greater than 50 nm, at least 50 nm and no greater than 60 nm, at least 60 nm and no greater than 70 nm, at least 70 nm and no greater than 80 nm, at least 80 nm and no greater than 90 nm, at least 90 nm and no greater than 100 nm, at least 100 nm and no greater than 120 nm, at least 120 nm and no greater than 140 nm, at least 140 nm and no greater than 160 nm, at least 160 nm and no greater than 180 nm, at least 180 nm and no greater than 200 nm, at least 200 nm and no greater than 220 nm, at least 220 nm and no greater than 240 nm, at least 240 nm and no greater than 260 nm, at least 260 nm and no greater than 280 nm, at least 280 nm and no greater than 300 nm, and / or the like.

[0090] As further nonlimiting examples, the polymer brush layer can have a thickness of approximately 5 nm, approximately 10 nm, approximately 20 nm, approximately 30 nm, approximately 40 nm, approximately 50 nm, approximately 60 nm, approximately 70 nm, approximately 80 nm, approximately 90 nm, approximately 100 nm, approximately 120 nm, approximately 140 nm, approximately 160 nm, approximately 180 nm, approximately 200 nm, approximately 220 nm, approximately 240 nm, approximately 260 nm, approximately 280 nm, approximately 300 nm, and / or the like.

[0091] The primer layer can include or be prepared using any type of polymer or copolymer and / or using any type of polymerization technique deemed suitable or relevant by a person of ordinary skill in the art, upon reviewing the entirety of this disclosure. As a nonlimiting example, for the case of a copolymer, the primer layer can also include or be prepared using two or more types of monomers at any molar ratio deemed suitable or relevant by a person of ordinary skill in the art, upon reviewing the entirety of this disclosure. In some embodiments, the primer layer can include anacrylate or methacrylate polymer. In some embodiments, the primer layer can include or be prepared using 2-(acetoacetoxy)ethyl methacrylate (AAEMA or simply A) as a monomer. In some embodiments, the primer layer can include or be prepared using methyl methacrylate (MA or simply M) as a monomer. In some embodiments, the primer layer can include or be prepared using / / -butyl acrylate (nBA or simply B) as a monomer. In some embodiments, the primer layer can include or be prepared using / / -hexyl methacrylate (HMA) as a monomer. In some embodiments, the primer layer can include or be prepared using ethyl hexyl methacrylate as a monomer. In some embodiments, the primer layer can be prepared using chain-growth polymerization. In some embodiments, the primer layer can be prepared using step-growth polymerization. The primer layer and / or polymer brush layer can have any number average molecular weight and / or dispersity deemed suitable or relevant by a person of ordinary skill in the art, upon reviewing the entirety of this disclosure.

[0092] In some embodiments, the primer layer can include a terpolymer of 2- (acetoacetoxy)ethyl methacrylate (AAEMA or simply A), methyl methacrylate (MA or simply M), and / / -butyl acrylate (nBA or simply B), as described in further detail below.

[0093] In some embodiments, the terpolymer of the primer layer can include at least 1 mol% and no greater than 60 mol% of AAEMA. As nonlimiting examples, the terpolymer can include at least 1 mol% and no greater than 2 mol%, at least 2 mol% and no greater than 3 mol%, at least 3 mol% and no greater than 4 mol%, at least 4 mol% and no greater than 5 mol %, at least 5 mol% and no greater than 6 mol%, at least 6 mol% and no greater than 7 mol%, at least 7 mol% and no greater than 8 mol%, at least 8 mol% and no greater than 9 mol%, at least 9 mol% and no greater than 10 mol%, at least 10 mol% and no greater than 20 mol%, at least 20 mol% and no greater than 30 mol%, at least 30 mol% and no greater than 40 mol%, at least 40 mol% and no greater than 50 mol%, at least 50 mol% and no greater than 60 mol%, etc., of AAEMA. As further nonlimiting examples, the terpolymer can include approximately 1 mol%, approximately 2 mol%, approximately3 mol%, approximately 4 mol%, approximately 5 mol%, approximately 6 mol%, approximately 7 mol%, approximately 8 mol%, approximately 9 mol%, approximately 10 mol%, approximately 20 mol%, approximately 30 mol%, approximately 40 mol%, approximately 50 mol%, approximately 60 mol%, and / or the like, of AAEMA.

[0094] In some embodiments, the terpolymer of the primer layer can include at least 35 mol% and no greater than 55 mol% of MA. As nonlimiting examples, the terpolymer can include at least 35 mol% and no greater than 40 mol%, at least 40 mol% and no greater than 41 mol%, at least 41 mol% and no greater than 42 mol%, at least 42 mol% and no greater than 43 mol%, at least 43 mol%and no greater than 44 mol%, at least 44 mol% and no greater than 45 mol%, at least 45 mol% and no greater than 46 mol%, at least 46 mol% and no greater than 47 mol%, at least 47 mol% and no greater than 48 mol%, at least 48 mol% and no greater than 49 mol%, at least 49 mol% and no greater than 50 mol%, at least 50 mol% and no greater than 55 mol%, etc., of MA. As further nonlimiting examples, the terpolymer can include approximately 35 mol%, approximately 40 mol%, approximately 41 mol%, approximately 42 mol%, approximately 43 mol%, approximately 44 mol%, approximately 45 mol%, approximately 46 mol%, approximately 47 mol%, approximately 48 mol%, approximately 49 mol%, approximately 50 mol%, approximately 55 mol%, and / or the like, of MA.

[0095] In some embodiments, the terpolymer of the primer layer can include at least 40 mol% and no greater than 60 mol% of nBA. As nonlimiting examples, the terpolymer can include at least 40 mol% and no greater than 45 mol%, at least 45 mol% and no greater than 46 mol%, at least 46 mol% and no greater than 47 mol%, at least 47 mol% and no greater than 48 mol%, at least 48 mol% and no greater than 49 mol%, at least 49 mol% and no greater than 50 mol%, at least 50 mol% and no greater than 51 mol%, at least 51 mol% and no greater than 52 mol%, at least 52 mol% and no greater than 53 mol%, at least 53 mol% and no greater than 54 mol%, at least 54 mol% and no greater than 55 mol%, at least 55 mol% and no greater than 60 mol%, etc., of nBA. As further nonlimiting examples, the terpolymer can include approximately 40 mol%, approximately 45 mol%, approximately 46 mol%, approximately 47 mol%, approximately 48 mol%, approximately 49 mol%, approximately 50 mol%, approximately 51 mol%, approximately 52 mol%, approximately 53 mol%, approximately 54 mol%, approximately 55 mol%, approximately 60 mol%, and / or the like, of nBA.

[0096] In some embodiments, the terpolymer of the primer layer can include AAEMA, MA, and nBA in a molar ratio of approximately 5:45:50.

[0097] In some embodiments, the primer layer can include a bipolymer of AAEMA and / / -hexyl methacrylate (HMA), as described in further detail below.

[0098] In some embodiments, the bipolymer of the primer layer can include at least 25 mol% and no greater than 45 mol% of AAEMA. As nonlimiting examples, the bipolymer can include at least 25 mol% and no greater than 30 mol%, at least 30 mol% and no greater than 31 mol%, at least 31 mol% and no greater than 32 mol%, at least 32 mol% and no greater than 33 mol%, at least 33 mol% and no greater than 34 mol%, at least 34 mol% and no greater than 35 mol%, at least 35 mol% and no greater than 36 mol%, at least 36 mol% and no greater than 37 mol%, at least 37 mol% and no greater than 38 mol%, at least 38 mol% and no greater than 39 mol%, at least 39 mol% and no greater than 40 mol%, at least 40 mol% and no greater than 45 mol%, etc., of AAEMA. As furthernonlimiting examples, the terpolymer can include approximately 25 mol%, approximately 30 mol%, approximately 31 mol%, approximately 32 mol%, approximately 33 mol%, approximately 34 mol%, approximately 35 mol%, approximately 36 mol%, approximately 37 mol%, approximately 38 mol%, approximately 39 mol%, approximately 40 mol%, approximately 45 mol%, and / or the like, of AAEMA.

[0099] In some embodiments, the bipolymer of the primer layer can include at least 55 mol% and no greater than 75 mol% of HMA. As nonlimiting examples, the bipolymer can include at least 55 mol% and no greater than 60 mol%, at least 60 mol% and no greater than 61 mol%, at least 61 mol% and no greater than 62 mol%, at least 62 mol% and no greater than 63 mol%, at least 63 mol% and no greater than 64 mol%, at least 64 mol% and no greater than 65 mol%, at least 65 mol% and no greater than 66 mol%, at least 66 mol% and no greater than 67 mol%, at least 67 mol% and no greater than 68 mol%, at least 68 mol% and no greater than 69 mol%, at least 69 mol% and no greater than 70 mol%, at least 70 mol% and no greater than 75 mol%, etc., of HMA. As further nonlimiting examples, the terpolymer can include approximately 55 mol%, approximately 60 mol%, approximately 61 mol%, approximately 62 mol%, approximately 63 mol%, approximately 64 mol%, approximately 65 mol%, approximately 66 mol%, approximately 67 mol%, approximately 68 mol%, approximately 69 mol%, approximately 70 mol%, approximately 75 mol%, and / or the like, of HMA.

[0100] In some embodiments, the bipolymer of the primer layer can include AAEMA and HMA at a molar ratio of approximately 35:65.Surface

[0101] As used herein, a “surface” is an area exposed by a solid semi-solid object to which one or more chemical species can be applied, tethered, or attached. The surface described herein can include any type of surface deemed suitable or relevant by a person of ordinary skill in the art, upon reviewing the entirety of the disclosure. In some embodiments, the surface can include a planar surface with no observable curvature to the naked eye. In some embodiments, the surface can include a substantially planar surface, i.e., a surface that can be locally treated as flat despite having an extended curvature. In some embodiments, the surface can include a curved, bent, angled, beveled, or corrugated surface with one or more ridges, troughs, facets, edges, vertices, and / or the like. In some embodiments, the surface can include a surface of one or more materials selected from a group consisting of silica, glass, ceramic, polymer, resin, metal, and metal alloy. As used herein, a “resin” is a type of polymer that can harden permanently to adopt a rigid, well-defined shape.

[0102] In some embodiments, the surface can include one or more surfaces of a wafer or substrate. As used herein, a “wafer” is a thin slice of material. As nonlimiting examples, a wafer can be constructed using one or more semiconductor materials, such as without limitation silicon, silica / silicon dioxide, silicon carbide, germanium, gallium nitride, gallium arsenide, indium phosphide, and / or the like. As used herein, a “substrate” is a material, or a surface of the material, that serves as the foundation for one or more coating layers to be applied thereto. As a nonlimiting example, a substrate can include an inorganic substrate such as without limitation silicon dioxide or silica. As a further nonlimiting example, a substrate can include an amorphous or noncrystalline substrate, such as without limitation glass. As a further nonlimiting example, a substrate can include a transparent substrate, such as without limitation glass, treated glass including without limitation laminated safety glass, plexiglass, Lexan polycarbonate, acrylic plastics including without limitation stretched acrylic, reinforced glass, and / or the like. As a further nonlimiting example, a substrate can include a ceramic such as without limitation silica or silicon dioxide, silicon carbide, polysiloxanes, magnesium oxide, aluminum oxide, zinc oxide, nickel(II) oxide, titanium oxide, indium tin oxide, and / or the like. As a further nonlimiting example, a substrate can include a polymer or resin, such as without limitation polyethylene (PE), polyethylene terephthalate (PETE), polypropylene (PP), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), poly(methyl methacrylate) (PMMA), polyacrylonitrile (PAN), polycarbonate (PC), polystyrene (PS), and / or the like. As a further nonlimiting example, a substrate can include a metal or metal alloy, including without limitation a metal or metal alloy based on element(s) such as iron, manganese, nickel, chromium, cobalt, copper, molybdenum, vanadium, titanium, aluminum, silicon, carbon, and / or the like. As a further nonlimiting example, a substrate can include a composite material such as fiberglass. As a further nonlimiting example, a substrate can include carbon fiber.Coated Polymer

[0103] The CAN within the self-healing composition further includes a coated polymer crosslinked with the primer layer through a reversible covalent linkage. The coated polymer can be applied to the primer layer using any suitable method or technique recognized by a person of ordinary skill in the art, upon reviewing the entirety of this disclosure. In some embodiments, the coated polymer can be applied via spray coating a polymer or polymer solution. In some embodiments, the coated polymer can be applied using a brush, roller, or applicator, or via dropcasting, spin-coating, dip-coating, etc. the coated polymer can include any type of polymer described above regarding the primer layer. In some embodiments, the coated polymer can include an acrylateor methacrylate polymer. In some embodiments, the primer layer can include or be prepared using 2- (acetoacetoxy)ethyl methacrylate (AAEMA or simply A) as a monomer. In some embodiments, the primer layer can include or be prepared using methyl methacrylate (MA or simply M) as a monomer. In some embodiments, the primer layer can include or be prepared using / / -butyl acrylate (nBA or simply B) as a monomer. In some embodiments, the primer layer can include or be prepared using n- hexyl methacrylate (HMA) as a monomer. In some embodiments, the primer layer can include or be prepared using ethyl hexyl methacrylate as a monomer. In some embodiments, the coated polymer can include a terpolymer of AAEMA, MA, and nBA. In some embodiments, the coated polymer can include a bipolymer of AAEMA and HMA. In some embodiments, the coated polymer can have a composition of monomers similar to or consistent with the composition of the primer layer described elsewhere in this disclosure. In some embodiments, the terpolymer of the coated polymer can include at least 1 mol% and no greater than 60 mol% of AAEMA. As nonlimiting examples, the coated polymer can include at least 1 mol% and no greater than 2 mol%, at least 2 mol% and no greater than 3 mol%, at least 3 mol% and no greater than 4 mol%, at least 4 mol% and no greater than 5 mol%, at least 5 mol% and no greater than 6 mol%, at least 6 mol% and no greater than 7 mol%, at least 7 mol% and no greater than 8 mol%, at least 8 mol% and no greater than 9 mol%, at least 9 mol% and no greater than 10 mol%, at least 10 mol% and no greater than 15 mol%, at least 15 mol% and no greater than 20 mol%, at least 20 mol% and no greater than 30 mol%, at least 30 mol% and no greater than 40 mol%, at least 40 mol% and no greater than 50 mol%, at least 50 mol% and no greater than 60 mol%, etc., of AAEMA. As further nonlimiting examples, the coated polymer can include approximately 1 mol%, approximately 2 mol%, approximately 3 mol%, approximately 4 mol%, approximately 5 mol%, approximately 6 mol%, approximately 7 mol%, approximately 8 mol%, approximately 9 mol%, approximately 10 mol%, approximately 15 mol%, approximately 20 mol%, approximately 30 mol%, approximately 40 mol%, approximately 50 mol%, approximately 60 mol%, and / or the like, of AAEMA.

[0104] In some embodiments, the coated polymer can have a number average molecular weight of at least 20 kg / mol and no greater than 100 kg / mol. As used herein, a “number average molecular weight” or “Mn” is the ordinary arithmetic mean or average of molecular masses of individual (macro)molecules, which is determined by measuring the molar masses of n polymer molecules, summing the molar masses, and dividing the sum by n. Mnshould be contrasted with number average molecular weight, Mw, which is calculated by summing the product of the molar mass of each polymer chain and its weight fraction, then dividing the sum by the total weight of the polymerinstead. Since a larger molecule will have a larger contribution than a smaller molecule when calculating Mw, Mwand Mnare often not the same value, with Mwalmost always larger than Mn.

[0105] As nonlimiting examples, the coated polymer can have a number average molecular weight of at least 20 kg / mol and no greater than 30 kg / mol, at least 30 kg / mol and no greater than 32 kg / mol, at least 32 kg / mol and no greater than 34 kg / mol, at least 34 kg / mol and no greater than 36 kg / mol, at least 36 kg / mol and no greater than 38 kg / mol, at least 38 kg / mol and no greater than 39 kg / mol, at least 39 kg / mol and no greater than 40 kg / mol, at least 40 kg / mol and no greater than 41 kg / mol, at least 41 kg / mol and no greater than 42 kg / mol, at least 42 kg / mol and no greater than 44 kg / mol, at least 44 kg / mol and no greater than 46 kg / mol, at least 46 kg / mol and no greater than 48 kg / mol, at least 48 kg / mol and no greater than 50 kg / mol, at least 50 kg / mol and no greater than 60 kg / mol, at least 60 kg / mol and no greater than 70 kg / mol, at least 70 kg / mol and no greater than 80 kg / mol, at least 80 kg / mol and no greater than 90 kg / mol, at least 90 kg / mol and no greater than 100 kg / mol, and / or the like. As further nonlimiting examples, the coated polymer can have a number average molecular weight of approximately 20 kg / mol, approximately 30 kg / mol, approximately 32 kg / mol, approximately 34 kg / mol, approximately 36 kg / mol, approximately 38 kg / mol, approximately 39 kg / mol, approximately 39.2 kg / mol, approximately 39.4 kg / mol, approximately 39.6 kg / mol, approximately 39.8 kg / mol, approximately 40 kg / mol, approximately 41 kg / mol, approximately 42 kg / mol, approximately 44 kg / mol, approximately 46 kg / mol, approximately 48 kg / mol, approximately 50 kg / mol, approximately 60 kg / mol, approximately 70 kg / mol, approximately 80 kg / mol, approximately 90 kg / mol, approximately 100 kg / mol, and / or the like.

[0106] In some embodiments, the coated polymer can have a dispersity of at least 2.0 and no greater than 5.0. As used herein, “dispersity”, “D”, or “D-stroke” is a measure of the spread or width of the molecular weight distribution within a polymer composition. Dispersity can be calculated by dividing the weight average molecular weight (Mw) by the number average molecular weight (Mn) of a polymer sample. Dispersity was formerly known as the poly dispersity index (PD1), and a smaller value of dispersity generally indicates a more uniform (i.e., monodisperse) polymer composition, with the value of Mwbeing closer to the value of Mn.

[0107] As nonlimiting examples, the coated polymer can have a dispersity of at least 2.0 and no greater than 2.5, at least 2.5 and no greater than 2.6, at least 2.6 and no greater than 2.7, at least 2.7 and no greater than 2.8, at least 2.8 and no greater than 2.9, at least 2.9 and no greater than 3.0, at least 3.0 and no greater than 3.1, at least 3.1 and no greater than 3.2, at least 3.2 and no greater than 3.3, at least 3.3 and no greater than 3.4, at least 3.4 and no greater than 3.5, at least 3.5 and nogreater than 4.0, at least 4.0 and no greater than 4.5, at least 4.5 and no greater than 5.0, and / or the like. As further nonlimiting examples, the coated polymer can have a dispersity of approximately 2.0, approximately 2.5, approximately 2.6, approximately 2.7, approximately 2.8, approximately 2.9, approximately 3.0, approximately 3.1, approximately 3.2, approximately 3.3, approximately 3.4, approximately 3.5, approximately 4.0, approximately 4.5, approximately 5.0, and / or the like. Reversible Covalent Linkage

[0108] A used herein, a “reversible covalent linkage” is a chemical structure that links between two chemical species, or two portions within the same chemical species, using one or more reversible covalent bonds. As used herein, a “reversible” covalent bond is a type of covalent bond whose formation and dissociation can proceed in a reversible or substantially reversible manner. In other words, a reversible covalent bond establishes between the bonded and unbonded states a chemical equilibrium with no strong preference for either, and by applying Le Chatelier’s Principle, the reversible covalent bond can be readily broken or (re)formed. On a macroscopic scale, when the structural integrity of a material is damaged, e.g., by an applied shearing force, such reversibility imparts the material an ability to reform the broken chemical bonds and self-heal.

[0109] The reversible covalent linkage described herein can implement any type of crosslink exchange reaction or chemistry, or be based on any reversible covalent bond, that is deemed suitable or relevant by a person of ordinary skill in the art, upon reviewing the entirety of this disclosure. In some embodiments, the reversible covalent linkage or reversible covalent bond can include a vinylogous urethane group or a vinylogous urea group (e.g., for a Michael addition reaction or urethane / urea exchange reaction), a cyclohexenyl group (e.g., for a reversible Diels-Alder reaction), a 1,2,3-triazolium group (e.g., for a transalkylation reaction), an ester group (e.g., for a transesterification reaction of epoxy / acid, epoxy / anhydride, or boronic ester networks), a siloxane group (e.g., for a siloxane exchange reaction or a silanol / siloxane exchange reaction), an olefin group (e.g., for an olefin metathesis reaction), a disulfide group (e.g., for a disulfide exchange reaction), a carbamate group (e.g., for a transcarbamoylation reaction), a trithiocarbonate group (e.g., for a trithiocarb onate exchange reaction), an alkoxyamine group (e.g., for an alkoxyamine exchange reaction), an imine group (e.g., for an imine metathesis reaction or an imine / amine exchange reaction), and / or the like. In some embodiments, the reversible covalent linkage or reversible covalent bond can include one or more members selected from a group consisting of a vinylogous urethane group, a vinylogous urea group, a cyclohexenyl group, a 1,2,3-triazolium group, an estergroup, a siloxane group, an olefin group, a disulfide group, a carbamate group, a tri thiocarb onate group, an alkoxy amine group, and an imine group.T?and Tv

[0110] In some embodiments, the composition described herein can have a glass transition temperature (Zg) of at least 30 °C and no greater than 80 °C. As used herein, a “glass transition temperature” or “Zg” is the temperature which a polymer network transitions between a glassy state and a rubbery state. As nonlimiting examples, the composition described herein can have a T%of at least 30 °C and no greater than 35 °C, at least 35 °C and no greater than 36 °C, at least 36 °C and no greater than 37 °C, at least 37 °C and no greater than 38 °C, at least 38 °C and no greater than 39 °C, at least 39 °C and no greater than 40 °C, at least 40 °C and no greater than 41 °C, at least 41 °C and no greater than 42 °C, at least 42 °C and no greater than 43 °C, at least 43 °C and no greater than 44 °C, at least 44 °C and no greater than 45 °C, at least 45 °C and no greater than 50 °C, at least 50 °C and no greater than 55 °C, at least 55 °C and no greater than 60 °C, at least 60 °C and no greater than 70 °C, at least 70 °C and no greater than 80 °C, and / or the like. As further nonlimiting examples, the composition described herein can have a Tsof approximately 30 °C, approximately 35 °C, approximately 36 °C, approximately 37 °C, approximately 38 °C, approximately 39 °C, approximately 40 °C, approximately 41 °C, approximately 42 °C, approximately 43 °C, approximately 44 °C, approximately 45 °C, approximately 50 °C, approximately 55 °C, approximately 60 °C, approximately 75°C, approximately 80°C, and / or the like.[OlH] In some embodiments, the composition described herein can have a topology freezing transition temperature (Tv) of at least 10 °C and no greater than 25 °C. As used herein, a “topology freezing transition temperature” or “Zv” is the temperature at which a polymer network transitions from a viscoelastic solid to a viscoelastic liquid. In some embodiments, such transition can be arbitrarily chosen based on a viscosity threshold of 1012Pa s. Tvtypically derives from network crosslink exchange reactions; when the timescale of bond exchange reactions becomes shorter than the timescale of material deformation, the network can rearrange its topology, resulting in flow. In some embodiments, Tvcan be higher than Tg. Accordingly, upon heating from a temperature below Tgto a temperature between Tgand Tv, a glassy solid can first transition to a rubbery state and behave as an elastomer, since the exchange reaction is so slow that the network structure is essentially fixed. Upon further heating, the exchange reaction can speed up and become relevant at temperatures above Tv, transforming the elastomer to a viscoelastic liquid, of which the flow is mainly controlled by the crosslink exchange kinetics, resulting in a typical Arrhenius-type viscositydecrease. In some embodiments, Tvcan be lower than Tg. This scenario is usually the case when an intrinsically fast exchange reaction is embedded in a rigid polymer matrix. Accordingly, Tvcan be calculated by extrapolation of stress-relaxation or creep experiments, and this transition is hypothetical since the network is not ultimately frozen by the reaction kinetics, but instead by the lack of segmental motions associated with Tg. At temperatures below Tg, no segmental motion occurs, and consequently no exchange reactions can occur, and the network is fixed by the diffusion limit. Upon heating above the glass transition region of the material, segmental motion is gradually initiated while the exchange reactions are already fast. In this initial situation, network rearrangement kinetics is diffusion-controlled, and network topology rearrangements are dominated by segmental motions, which can result in a Williams-Landel-Ferry (WLF) viscosity behavior. Upon further heating, the exchange kinetics switches from a diffusion-controlled regime to an exchange reaction-controlled regime, which follows the Arrhenius equation. Details described herein can be consistent with any detail disclosed in Denissen, W. et al., “Vitrimers: permanent organic networks with glasslike fluidity”, Chem. Set., 2016; 7:30-38, the entirety of which is incorporated herein by reference.

[0112] As nonlimiting examples, the composition described herein can have a Tvof at least 10 °C and no greater than 11 °C, at least 11 °C and no greater than 12 °C, at least 12 °C and no greater than 13 °C, at least 13 °C and no greater than 14 °C, at least 14 °C and no greater than 15 °C, at least 15 °C and no greater than 16 °C, at least 16 °C and no greater than 17 °C, at least 17 °C and no greater than 20 °C, at least 20 °C and no greater than 25 °C, and / or the like. As further nonlimiting examples, the composition described herein can have a Tvof approximately 10 °C, approximately 11 °C, approximately 12 °C, approximately 13 °C, approximately 13.2 °C, approximately 13.5 °C, approximately 13.7 °C, approximately 14 °C, approximately 15 °C, approximately 16 °C, approximately 17 °C, approximately 20 °C, approximately 25 °C, and / or the like.Seal-Healing Kinetics

[0113] In some embodiments, the composition described herein can self-heal an incision therein within 60 s under a temperature of at least 160 °C. In some embodiments, the composition described herein can self-heal an incision therein within 60 s under a temperature of no greater than 200 °C. In some embodiments, the composition described herein can self-heal an incision therein within 60 s under a temperature of at least 160 °C and no greater than 200 °C. In some embodiments, such as without limitation under a certain elevated temperature, the composition described herein can self-heal an incision therein within 55 s, within 50 s, within 45 s, within 40 s, within 35 s, within 30 s, and / or the like.Method of Preparing the Composition

[0114] Another objective of the present disclosure is directed towards preparing the self-healing composition of matter described herein. The composition of matter can be prepared using any method of preparation described in this disclosure. The method includes preparing a primer layer tethered to a surface and spray coating a polymer to the primer layer, wherein at least one portion of the polymer crosslinks with the primer layer through a reversible covalent linkage.

[0115] In some embodiments, preparing the primer layer includes immobilizing a chain transfer agent (CTA) onto the surface, such as without limitation through a reactive surface group (e.g., hydroxyl), and synthesizing the polymer brush layer using the immobilized CTA. As a nonlimiting example, hydroxyl groups can be created on the surface of a SiC wafer using Piranha solution.

[0116] As used herein, “immobilizing” is a process of attaching, tethering, or linking one end of a chemical species to a substrate. As used herein, a “chain transfer agent” or “CTA” is a chemical species or substance that is used to perform a chain transfer function in a polymerization reaction mixture. As used herein, “chain transfer” is a chemical process in which an active center of polymerization is transferred from one polymer molecule to another polymer molecule, or from one position or site of a polymer molecule to another position or site of the same polymer molecule. In other words, a chain transfer process results in the deactivation of the original chain carrier and the generation of a new chain. In some embodiments, such active center or chain carrier can be a radical from which a polymer chain grows or propagates. By such a chain transfer process, a CTA can control the molecular weight of a polymer to be synthesized. In some embodiments, for a reversible addition-fragmentation chain transfer polymerization (RAFT) reaction, the CTA can accordingly be termed a RAFT agent. Additional details will be provided below in this disclosure.

[0117] The CTA can include any type of CTA deemed suitable or relevant by a person of ordinary skill in the art, upon reviewing the entirety of this disclosure. In some embodiments, the CTA can include a dithioester, a dithiobenzoate, a dithiocarbamate, a trithiocarbonate, or a xanthate. In some embodiments, the CTA can include one or more members selected from a group consisting of dithioester, a dithiobenzoate, a dithiocarbamate, a trithiocarbonate, and a xanthate. In some embodiments, the CTA can include 4-cyano-4[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid (CDTPA).

[0118] In some embodiments, the primer layer or polymer brush layer can be synthesized using surface-initiated polymerization. As used herein, a “surface-initiated” polymerization is a type of polymerization reaction performed directly from a surface, substrate, wafer, or support instead of in a free-standing form.

[0119] In some embodiments, the surface-initiated polymerization can include or be implemented using reversible addition-fragmentation chain transfer polymerization (RAFT). As used herein, “reversible addition-fragmentation chain transfer polymerization” or “RAFT” is a type of living radical polymerization reaction that uses a CTA or RAFT agent to afford control over the molecular weight and dispersity of a polymer product.

[0120] In some embodiments, the surface-initiated polymerization can include or be implemented using photoinduced electron transfer-reversible addition-fragmentation chain transfer polymerization (SI-PET-RAFT). As used herein, “photoinduced electron transfer-reversible addition-fragmentation chain transfer polymerization” or “SI-PET -RAFT” is a type of surface- initiated RAFT driven by light, via a photoinduced electron transfer mechanism. A SI-PET-RAFT typically uses a photoactive chemical species, such as a photocatalyst, as described in further detail below. Upon absorbing a photon, one or more electrons within such photoactive chemical species are promoted to a photoexcited state. The photoexcited electron(s) is subsequently transferred to an electron acceptor, leaving behind a reactive photo-oxidized species, such as a radical cation, that can be used to sustain a polymerization reaction.

[0121] In some embodiments, the primer layer can be polymerized using a photocatalyst. As used herein, a “photocatalysf ’ is a chemical species that functions as a catalyst by capturing at least one portion of an electromagnetic spectrum and utilizing the energy therein to drive a chemical reaction. In some embodiments, a photocatalyst can be capable of operating far from a chemical equilibrium and driving a chemical reaction that is otherwise nonspontaneous (i.e., has a positive Gibbs free energy change). In some embodiments, a photocatalyst can simply increase the rate of an otherwise relatively sluggish chemical reaction. In some embodiments, a photocatalyst can utilize absorbed light energy to overcome an activation energy barrier, thereby increasing the rate constant of a chemical reaction. The catalytic function performed by a photocatalyst is accordingly termed photocatalysis.

[0122] In some embodiments, a photocatalyst can perform its photocatalytic function via a charge transfer mechanism, such as without limitation via photoinduced electron transfer and / or hole transfer. In such cases, one or more reactants or chemical moieties within the one or more reactantscan function as a charge transfer partner. In some embodiments, sacrificial electron scavengers or hole scavengers can be used to maintain charge balance. In some embodiments, a photocatalyst can include a photo-redox catalyst that participates in both oxidative and reductive steps in an overall redox-neutral chemical reaction, without a need for sacrificial electron scavengers or hole scavengers. Additionally, and / or alternatively, in some embodiments, a photocatalyst can perform its photocatalytic function via an energy transfer mechanism, such as without limitation via Forster resonance energy transfer and / or Dexter energy transfer. Such energy transfer can utilize the energy captured by a photocatalyst to promote one or more reactants or chemical moieties within the one or more reactants to their excited states. In some embodiments, a photocatalyst can include one or more photosensitizers configured to capture light energy. In some embodiments, a plurality of photosensitizers can form an assembly and distribute captured energy with one another, such as without limitation via Forster resonance energy transfer, which bears resemblance to Photosystem II in nature. In some embodiments, a photocatalyst can include one or more photocatalytic centers configured to use captured light energy to drive one or more chemical transformations. In some embodiments, a chemical species can function as both a photosensitizer and a photocatalytic center. In some embodiments, a photosensitizer can relay charges or redox equivalents, such as electron(s), hole(s), or both, to a photocatalytic center. In some embodiments, a photocatalytic center can transfer absorbed energy to one or more reactants via an energy transfer mechanism, such as without limitation Forster resonance energy transfer and / or Dexter energy transfer. In some embodiments, a photocatalytic center can relay one or more charges or redox equivalents, such as electron(s), hole(s), or both, to one or more reactants or chemical moieties within the one or more reactants.

[0123] As used herein, a “catalytic function” or “catalytic activity” is a capability of a chemical species to perform catalysis and function as a catalyst. As used herein, “catalysis” is a process wherein a chemical species accelerates a chemical reaction by lowering at least one activation barrier along a reaction coordinate and increases at least one rate constant associated with the at least one activation barrier. The chemical species capable of performing catalysis is accordingly classified as a catalyst. In some embodiments, to perform a catalytic function, a catalyst can first be consumed by one or more reactants to form one or more intermediates, then be regenerated as the one or more intermediates are converted to one or more products. In other words, a catalyst should not get consumed as a net result and accordingly should not be included as a reactant in a net chemical reaction. The catalytic function or activity of a catalyst can be described using mathematical tools or kinetic models such as Arrhenius equation, Eyring equation. Michaelis-Menten equation,Lineweaver-Burk equation, among others, as deemed suitable by a person of ordinary skill in the art upon reviewing the entirety of this disclosure.

[0124] In some embodiments, one or more reactants can bind / adsorb to a catalyst, participate in a chemical reaction, then dissociate / desorb from the catalyst as one or more products. In some embodiments, a catalyst can include a homogeneous catalyst, wherein the catalyst and reactant(s) are dispersed in the same phase (often a solution). In some embodiments, a catalyst can include a heterogeneous catalyst, wherein the catalyst and reactant(s) are dispersed in two or more distinct phases, with at least one interface in between. As a nonlimiting example, a heterogeneous catalyst can be included in a solid phase, and one or more reactants can be dispersed in a gas phase; a chemical reaction catalyzed by the heterogeneous catalyst can accordingly occur at an interface between the solid phase and the gas phase. In some embodiments, a catalyst, such as a heterogeneous catalyst, can have a large specific surface area for one or more reactants to bind / adsorb to and react. In some embodiments, a heterogeneous catalyst can be implemented as a supported catalyst. As used herein, a “supported catalyst” is a type of catalyst wherein one or more materials with catalytic activity are supported by a porous, catalytically inactive matrix to increase the specific surface area thereof.

[0125] The photocatalyst described herein can include any photocatalyst deemed suitable by a person of ordinary skill in the art, upon reviewing the entirety of this disclosure. In some embodiments, the photocatalyst can include a coordination complex. As used herein, a “coordination complex” is an inorganic compound with a metal or metal ion center connected to and stabilized by one or more chemical species, termed ligands, through one or more coordinate covalent bonds. In some embodiments, the photocatalyst can include an organometallic compound. As used herein, an “organometallic compound” is a metal-containing chemical species that contains at least one metal- carbon bond.

[0126] In some embodiments, the photocatalyst can include a coordination complex or organometallic compound containing one or more metal centers such as Ir, Ru, Zn, Fe, Cu, and / or the like. In some embodiments, the photocatalyst can include a substituted or unsubstituted zinc tetraphenylporphyrin (ZnTPP). In some embodiments, the photocatalyst or coordination complex can include a compound of substituted or unsubstituted tris(bipyridine)ruthenium(II) ([Ru(bpy)s]2+), such as without limitation a chloride salt thereof ([Ru(bpy)3]Ch). In some embodiments, the photocatalyst or coordination complex can include a substituted or unsubstituted tris(2- phenylpyridine)iridium ([Ir(ppy)3]), such as without limitation / ic-flrfppy ) ] .

[0127] In some embodiments, the photocatalyst can include a semiconductor material such as without limitation TiCE, ZnO, and colloidal quantum dots. In some embodiments, the photocatalyst can include an organic molecule, including without limitation xanthene dye and derivatives thereof, fluorescein, Eosin Y, phenothiazine and derivatives thereof, phenoxazine and derivatives thereof, rose bengal, rhodamine B, perylene diimide (PDI) and derivatives thereof, perylene and derivatives thereof, among others.

[0128] In some embodiments, the photocatalyst can be illuminated using blue light, such as without limitation blue light at a wavelength of 405 nm. In some embodiments, the photocatalyst can be illuminated by a broadband light source that covers a relatively wide spectral window. In some embodiments, the photocatalyst can be illuminated by a narrowband light source that is relatively focused within a specific wavelength / frequency range, such as UV light (e.g., in a wavelength range of 100-400 nm, 100-280 nm, 280 nm-315 nm, 315-400 nm, etc.), blue light (e.g., in a wavelength range of 400-500 nm, 400-450 nm, 400-420 nm, etc.), green light (e.g., in a wavelength range of 500-570 nm), etc. The catalyst can be illuminated or powered by any type of light source deemed suitable by a person of ordinary skill in the art upon reviewing the entirety of this disclosure, such as without limitation sunlight, mercury vapor lamps, xenon lamps, metal halide lamps, light-emitting diodes (LEDs), fluorescent lamps, laser diodes, tungsten halogen lamps, and / or the like.

[0129] In some embodiments, the polymer to be coated can be synthesized using free radical polymerization. In some embodiments, the free radical polymerization can be initiated using an initiator such as without limitation azobisisobutyronitrile (AIBN, also known as a, a’ - azoisobutyronitrile or 2,2’-azobis(2-methylpropionitrile)), l,l’-azobis(cyclohexanecarbonitrile) (ABCN), di- / -butyl peroxide (DTBP), benzoyl peroxide (BPO), methyl ethyl ketone peroxide (MEKP), acetone peroxide (APEX), a peroxy di sulfate salt, a carbon halide, a benzenesulfonic acid ester, an alkyl sulfonium salt, 2,2’-azobis[2-(2-imidazolin-2-yl)propane] di hydrochloride, / -butyl hydroperoxide (TBHP), cumene hydroperoxide, dicumyl peroxide, ammonium persulfate (APS), and / or the like.

[0130] In some embodiments, coating the polymer can include applying, e.g., spray coating, a solution of the polymer. The solution can contain any organic, non-organic (e.g., aqueous), protic, or aprotic solvent or solvent mixture in accordance with the “like dissolves like principle” or otherwise deemed suitable by a person of ordinary skill in the art, upon reviewing the entirety of this disclosure. As a nonlimiting example, the solution can include toluene, tetrahydrofuran (THF), or acetone as a solvent. As another nonlimiting example, the solution can include water as a solvent.

[0131] In some embodiments, the solution to be applied or spray coated can further include a crosslinking agent. As used herein, a “crosslinking agent” is a chemical species used to react with and connect two or more chemical species and create a reversible covalent linkage or bond therebetween. In some embodiments, the crosslinking agent can include two, three, four, or more reactive groups per molecule. Nonlimiting examples of such reactive groups can include without limitation amines, hydroxyls, carbonyls, carboxylic acids, azides, alkenes, and / or the like. In some embodiments, the crosslinking agent can include tris(2-aminoethyl) amine (TREN). In some embodiments, the polymer to be applied or spray-coated can include AAEMA monomer units and a crosslinking agent (e.g., TREN) in a molar ratio of 1 : 1 to 5: 1, e g., approximately 2: 1 . Additionally, and / or alternatively, in some embodiments, the crosslinking agent can include m-xylylenediamine.

[0132] In some embodiments, the polymer or the solution of the polymer can be spray coated using an airbrush spray jet. Any airbrush spray jet or device / system similar thereto deemed suitable by a person of ordinary skill in the art, upon reviewing the entirety of this disclosure, can be used to perform such a step. As used herein, an “airbrush spray jet” is a device that uses compressed air to disperse a medium through a small, tapered opening, allowing for a precise and controlled application of the medium. The airbrush spray jet can be operated under any flow rate deemed suitable or feasible by a person of ordinary skill in the art, upon reviewing the entirety of this disclosure. In some embodiments, the airbrush spray jet can be operated at a flow rate of 100-300 pL / s. As nonlimiting examples, the airbrush spray jet can be operated at a flow rate of 100-110 pL / s, 110-120 pL / s, 120-130 pL / s, 130-140 pL / s, 140-150 pL / s, 150-160 pL / s, 160-170 pL / s, 170-180 pL / s, 180-190 pL / s, 190-200 pL / s, 200-220 pL / s, 220-240 pL / s, 240-260 pL / s, 260-280 pL / s, 280- 300 pL / s, etc. As further nonlimiting examples, the airbrush spray jet can be operated at a flow rate of approximately 100 pL / s, approximately 110 pL / s, approximately 120 pL / s, approximately 130 pL / s, approximately 140 pL / s, approximately 150 pL / s, approximately 160 pL / s, approximately 170 pL / s, approximately 180 pL / s, approximately 190 pL / s, approximately 200 pL / s, approximately 220 pL / s, approximately 240 pL / s, approximately 260 pL / s, approximately 280 pL / s, approximately 300 pL / s, etc. It is worth noting that the method of preparation described herein is not limited to spray coating only. In some embodiments, drop coating can be used in addition to or instead of spraycoating. In some embodiments, the polymer or the solution of the polymer can be applied using a brush, roller, or applicator, or via drop-casting, spin-coating, dip-coating, etc.Use / Methods of Use

[0133] Another objective of the present disclosure is directed towards preparing a self-healing surface. The method including applying or tethering to a surface the composition described herein. In some embodiments, the method can further include drying or curing the composition to produce a coating layer. As nonlimiting example, a (spray-)coated fdm can be cured under vacuum and room temperature for 6 h, followed by 20 h under vacuum at 75 °C to obtain a final vitrimer coating.

[0134] Another objective of the present disclosure is directed towards the use of the composition described herein for preparing a scratch-resistant, solvent-resistant, anti-fouling, or anticorrosion coating layer. As used herein, a “scratch-resistant” coating layer is a coating layer that is more difficult to scratch, cut, scrape, dent, or damage by an applied force or pressure. As a nonlimiting example, a scratch-resistant coating layer can be applied to specialty optics that require a smooth, substantially defect-free surface to minimize scattering of light. As used herein, a “solvent- resistant” coating layer is a coating layer that is less likely to dissolve, shed, peel, or delaminate once exposed to a solvent. As a nonlimiting example, a solvent-resistant coating layer can be applied to components of a fume hood in a chemistry lab that are frequently exposed to organic solvents. As used herein, an” anti-fouling” or “adhesion-resistant” coating layer is a coating layer with a reduced tendency to bind to one or more unwanted chemical species. As a nonlimiting example, an antifouling coating layer can be used to prevent to growth of biofilms. As used herein, an “anticorrosion” coating layer is a coating layer with a reduced chemical reactivity against a corrosive chemical species. As a nonlimiting example, an anti-corrosion coating layer can be applied to metal surfaces frequently exposed to strong acids, oxidants, or saline solutions.Coating Materials and Coated Surfaces

[0135] Another objective of the present disclosure is directed towards a coating material or coating layer including the composition described herein. The coating material can include any composition and / or be prepared using any method of preparation described herein. The coating material or coating layer can also adopt any thickness deemed suitable, relevant, or feasible by a person of ordinary skill in the art, upon reviewing the entirety of this disclosure. As nonlimiting examples, the coating material can have a thickness of approximately 10 pm, approximately 20 pm, approximately 30 pm, approximately 40 pm, approximately 50 pm, approximately 60 pm, approximately 70 pm, approximately 80 pm, approximately 90 pm, approximately 100 pm, approximately 200 pm, approximately 300 pm, approximately 400 pm, approximately 500 pm, and / or the like.

[0136] Another objective of the present disclosure is directed towards a coated surface including a substrate and the composition described herein applied or tethered to the substrate. The coated surface can be created on any surface, substrate, wafer, or material described herein, using any composition described herein, and / or be prepared using any method of preparation described herein.Article of Manufacture

[0137] Another objective of the present disclosure is directed towards an article of manufacture including the composition described herein. The article of manufacture can include any suitable article of manufacture in which a treated or protected surface is required, preferred, or desired, for any utilitarian or ornamental purposes or the like. As nonlimiting examples, the article of manufacture can include household appliances such as coffee machines, dishwashers, stoves, microwaves, etc. As further nonlimiting examples, the article of manufacture can include a component of an automobile or aircraft such as a hood, a bumper, a window, a sunroof, a light housing, a fuselage, a wing, a landing gear, etc. As further nonlimiting examples, the article of manufacture can include a construction material such as a glass panel or skylight for an office or residential building. As further nonlimiting examples, the article of manufacture can include a consumer product such as a CD, a DVD, safety goggles, protective glasses, shatter-proof sunglasses, a face shield, an ophthalmic lens, a watch, a water bottle, and / or the like. As further nonlimiting examples, the article of manufacture can include an article for food storage and / or packaging, such as without limitation a lunch box or a thermos. As further nonlimiting examples, the article of manufacture can include a high-precision component, such as without limitation a cuvette or optic filter or lens in a lab equipment or medical device.Additional Applications

[0138] Another objective of the present disclosure is directed towards a method of increasing scratch resistance, corrosion resistance, solvent resistance, or adhesion resistance of a surface. The method includes applying or tethering to a substrate the composition described herein, consistent with details elaborated elsewhere in this disclosure.EXAMPLESRapid Self-Healing of Robust Surface-Tethered Covalent Adaptable Coatings Results and DiscussionPreparation of Self-Healing Covalently Adaptive Coatings

[0139] Robust self-healing coatings were fabricated by combining (1) surface-initiated polymerization to grow polymer brushes (as a primer / anchor layer) and (2) spray coating of an analogous polymer (see FIG. 1 with characteristics of the terpolymer shown in FIGS. 7-10). Spray coating is a method that is scalable to large surface areas with efficient material use. A surface- initiated polymerization technique that would allow polymer brush synthesis from large surface areas, under ambient conditions, with a broad monomer and substrate scope, and with oxygen tolerance was chosen for this study. This study focused on surface-initiated photoinduced electron transfer-reversible addition-fragmentation chain transfer polymerization (SI-PET-RAFT).

[0140] SI-PET-RAFT initiating layers were formed by immobilizing a chain transfer agent (CTA), 4-cyano-4[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid (CDTPA), onto silica (SiCh) wafers though robust silane coupling chemistry. From these CDTPA monolayers, SI-PET- RAFT was used to synthesize a terpolymer including 2-(acetoacetoxy)ethyl methacrylate (A), methyl methacrylate (M), and / / -butyl acrylate (B), using zinc tetraphenylporphyrin (ZnTPP) as a photocatalyst (PC), under blue-light irradiation (zmax= 405 nm, I = 2400 lux), see FIG. 2A. The molar ratio of monomers was fixed at [A]:[M]:[B] = 5:45:50. The detailed chemical structures for each step of initiator-deposition and surface-initiated RAFT polymerization are shown in FIG. 12.

[0141] FIG. 2B shows increasing |~poly(AMB) brush film thickness with irradiation time as determined by variable angle spectroscopic ellipsometry (VASE). At a rate of ck / / dz = 20 nm / hr, |~poly(AMB) brushes grow to approximately 180 nm after 16 h of irradiation. After polymerization, the water contact angle of CTA-functionalized SiCh wafers increased from ^CDTPA = 64.0° to Poiy(AMB)= 70.5°. Further, the chemical composition of |~poly(AMB) was confirmed using X-ray photoelectron spectroscopy (XPS). The photoelectron spectrum (see FIG. 2C) shows the anticipated carbon Cis and oxygen Ols peaks at BEcis = 285 eV and BEois = 532 eV, respectively. The experimental Cls:01s peak ratio of 3: 1 matched well with the theoretically calculated ratio of Cls:01s = 2.9: 1. High-resolution Cis scans corroborated the anticipated chemical structure and showed distinct peaks for carbonyl groups (BE = 288.8 eV) and carbon-oxygen bonds (BE = 286.5 eV) at a ratio of C-C:C-O:C=O = 4: 1 : 1, which again aligned well with the theoretical ratio of 4 3: 1: 1 (FIG. 15).

[0142] For spray coating, an analogous poly(AMB) polymer, synthesized by free radical polymerization (A / n= 39.8 kg / mol, D = 3.0), was deposited on top of this |~poly(AMB) brush primer layer (see FIGS. 1, 8). Based on NMR analysis, it was determined that AAEMA units were incorporated within the terpolymer at a loading of 5 mol% (see FIG. 7). This polymer was mixedwith tris(2-aminoethyl) amine (TREN) in toluene, at a molar ratio of AAEMA unit:TREN = 2: 1, to form the spray-coating solution.

[0143] FIG. 3A shows the uniform and thick vitrimer coatings of d= 10-100 pm produced by spray coating the poly(AMB) / TREN solution described above using an airbrush spray jet. A flow rate of 130 pL / s was used at a nozzle-substrate distance of 3 cm. d depends on the number of deposition cycles or passes. FIG. 21 shows a photograph of the experimental setup. Films were dried and cured first under ambient conditions for 1 h, then under 75 °C, in vacuum, for 24 h, to form the desired vinylogous urethane CAN coatings (see FIG. 3B). This curing produced solvent-resistant and robust coatings due to the reversible covalent bonding between the spray-coated poly(AMB) and the |~poly(AMB) primer brush layer. A reduction in lability to common aggressive solvents, e.g., dichloromethane, toluene, N,N-dimethylformamide (DMF), and tetrahydrofuran (THF), was demonstrated on this bilayer material in comparison to physisorbed coatings that were not covalently tethered via a primer brush layer (see FIGS. 16A-B). After a prolonged exposure to solvent (e.g., toluene and / or DCM for 72 h), samples with the coating swelled, but the spray-coated layer did not delaminate. In contrast, the samples without the primer layer were either mostly or completely delaminated despite the reversible crosslinks inhibiting the dissolution of the coating.

[0144] Successful formation of the vitrimer coating was elucidated via tensiometry and XPS. The water contact angle of the resulting vitrimer coating was measured at q = 69° and matched that of the initial |~poly(AMB) polymer brush surface (q = 70°). XPS photoelectron spectra (see FIG. 3C) showed a nitrogen Nls peak at BENIS = 400 eV that results from incorporation of TREN into the polymer fdm. The Cls:Ols:Nls ratio was determined as 7.7:2.3:1, which again matched theoretical predictions of Cls:Ols:Nls = 7:2: 1, within experimental error. The high-resolution Cis XPS spectrum showed an expected increase of the 286.5 eV binding energy environment (see FIG. 15). This increase in binding energy was attributed to an increased number of carbon-nitrogen R3C-NR3 bonds present upon incorporation of TREN within the polymer layer.Self-Healing Studies

[0145] To interrogate the self-healing capabilities of the resulting covalently tethered CAN coatings, a razor blade was used to make incisions across their surfaces (see FIG. 4A). Complete self-healing was observed within 60 s under heat (T ~ 170 °C) and the incision was no longer visible (see FIG. 4B).

[0146] This healing process was captured as a function of time using optical profilometry under several different temperatures. This healing process can be accelerated using temperatures above 7gof the covalently adaptable network, but healing can also occur below Tg. Thermal properties of poly(AMB) / TREN CANs were determined as Zg= 42 °C and Tv= 13.5 °C. Zgand Tvwere determined using differential scanning calorimetry (DSC) and dynamic mechanical analysis with rheology, respectively, as shown in FIGS. 9-10. Stress relaxation further illustrates the rapid relaxation of the vitrimer at elevated temperatures (FIGS. 11A-B). FIG. 4C illustrates that at T= 160 °C (T» r„), complete self-healing of a 25 mm incision occurs within 60 s. Temperature was monitored with a non-contact infrared thermometer. At higher temperatures (T> 200 °C), degradation of the vitrimer coatings occurs (see FIG. 20). FIG. 4D shows the evolution of incision height and width as a function of time at T= 160 °C. These data were obtained from line slices of the profilometry data in FIG. 4C. The cut in the coating is initially symmetric with the depth and width of the defect being approximately 25 mm. The cut initially narrows and shallows upon heating, but the final recovery to a smooth continuous film takes longer. This initial jump in recovery is reminiscent of the recovery of nanoimprinted features on heating, where the jump is associated with the residual stresses remaining from the processing that generated the features. The scratch in the coating is from a mechanical deformation below Ts, where residual stresses near the damage are expected and relaxation of the stress can drive the initial healing.

[0147] Examination of FIG. 4D suggests that the recovery in the width of the defect is faster than the depth, which conforms to expectations about the residual stresses imposed on the network by a razor blade. FIGS. 5A-B quantify the evolution in the relative dimensions of a scratch in the coatings as a function of temperature. The rate of healing accelerates as the temperature is increased but is independent of the initial scratch depth (18.9-64.2 pm examined here). Differences in the rate of healing between the width and depth of the scratch are small except at the highest temperature tested (130 °C). Scratch recovery data from optical profilometry at additional temperatures are shown in FIGS. 19A-C. The rate of healing is exponential as shown by the fit lines in FIG. 5 A. This exponential recovery in dimension is comparable to the functional form for the recovery of nanoimprinted features. A characteristic time, T, which describes the healing of the cut towards a flat coating, can be extracted from such exponential recovery. The single-exponential recovery in the dimensions of the scratch is contrary to the stretched exponential that is required to fit the stress relaxation from a small-amplitude step strain. Moreover, the scratch healing kinetics are accelerated significantly in comparison to the stress relaxation from a small strain step, as shown in FIGS. 19A- C, with only 60% of the stress relaxed in the 60 s required to fully heal the scratch at 130 °C. These findings point to a role of the strain imparted during damage on the rate of recovery of the damage.

[0148] The temperature dependence of T is shown in FIG. 5B, where the characteristic time for self-healing increases precipitously at lower temperatures. This result differs from the typical expectations for Arrhenius dependence for the dynamics of bond exchange rates in vitrimers. However, the lower temperatures for the self-healing are in the glass formation regime and thus the rapid increase in the characteristic time is likely related to glass formation with Tg> Tv. The data in FIG. 5B can be described by the Vogel-Fulcher-Tamman (VFT) equation with the Vogel temperature of 281 K, which is consistent with typical expectations for the Vogel temperature being close to Tg. This result indicates that the rate of healing is limited not by the dynamics of the exchange of the vinylogous urethane bonds but by the segmental dynamics of the polymer at the temperatures examined. Extrapolation of the VFT fit to healing at room temperature underestimates T to be 1 .1 h. Observations of the self-healing of a scratch at 25 °C demonstrated that the depth decreased by 26%, while the width decreased by 20% over 3 days (FIG. 19C). Healing continued over the course of one month at ambient temperature, but the scratch did not fully heal. These data correspond to T = 11.4 days at room temperature, which is indicative of effective healing below Tg. Comparison with Non-Tethered Covalently Adaptive Network Films

[0149] It is important to highlight differences between the surface-tethered CAN coatings described above and physisorbed CAN films that can be formed by (spray) coating poly(AMB) / TREN mixtures onto bare S1O2 substrates. First, the network formation between the surface-tethered brush and the spray-coated poly(AMB) is vital to impart robustness. While physisorbed CAN films were readily delaminated in solvent environments, the surface-tethered CANs showed high solvent resistance (see FIGS. 16A-B). Second, successful self-healing of scratches that penetrated all the way to the substrate was possible only for surface-tethered CAN films, not for physisorbed CANs (see FIG. 24). Finally, control experiments of razor blade incision with non-brushed substrates illustrated the importance of surface-tethering with respect to shear delamination. The optical micrographs in FIG. 6 show how physisorbed CAN coatings readily delaminate as incisions are made. Shear delamination, in conjunction with solvent lability, has set forth two major limitations to self-healing coatings without covalent tethering. In contrast, the surface-tethered CAN remains properly attached to the substrate. As with any self-healing material, mass loss over the course of the coating’s damage inhibits complete self-healing, but large-scale defects that redistribute the coating locally can impede full healing in the absence of a continuous functional surface that can guide the vitrimer rearrangement across the defect through associative bond exchanges.Conclusion

[0150] This work described the development of self-healing coatings based on surface-tethered covalently adaptive networks (CANs). Surface-initiated polymerization was used to synthesize polymer brushes and then combined with a spray coating approach to engineer the surface-tethered CANs. Chemically, the coatings were based on reversible vinylogous urethane bonds formed between polymers containing 2-(acetoacetoxy)ethyl methacrylate repeat units (AAEMA) and tris(2- aminoethyl) amine (TREN) crosslinkers. Incorporation of the TREN crosslinking agent allowed reversible covalent bonding between the spray-coated and surface-tethered polymers. The utility of this approach was highlighted through the ability of coatings to fully self-heal incisions within seconds (at elevated temperatures), while the physiosorbed analogs do not achieve complete healing over the timeframes examined. Key to these advancements was the use of polymer brushes as a primer layer to attach the CAN. Without this polymer brush layer, the physisorbed CAN coatings lacked the ability to self-heal, were labile to solvent, and showed shear delamination upon scratching.Experimental InformationMaterials

[0151] 2-(acetoacetoxy)ethyl methacrylate (AAEMA), methyl methacrylate (MMA), / / -butyl acrylate (nBA), tris(2-aminoethyl) amine, 5,10,15,20-tetraphenyl-21H,23H-porphine zinc (ZnTPP), 2,2'-azobis(2-methylpropionitrile) (AIBN), and dimethyl sulfoxide (DMSO) were purchased from Sigma-Aldrich and used as received (unless otherwise noted). Toluene, isopropyl alcohol, and hexanes were purchased from Fisher Scientific and used as received. Deionized water (DIW) was used from the Pennsylvania State University’s Chemical and Biomedical Engineering building. Silicon wafers (with native oxide and 100-nm thermal oxide layers) were purchased from WaferPro, LLC (San Jose, CA). Thorlabs Olympus BX & IX series (X = 405 nm) collimated light-emitting diodes (LEDs) were used for all light-mediated surface-initiated polymerizations. A Thorlabs LED DIB T-cube driver was used to modulate light intensities.Instrumentation

[0152] Nuclear magnetic resonance (NMR) experiments were performed on a Bruker A VIII- HD-500 MHz smart probe spectrometer. 'H NMR spectra are reported in d units (parts per million) and normalized to the signal for deuterated chloroform (CDCh; d = 7.26 ppm). X-ray photoelectron spectra were measured using a Physical Electronics VersaProbe III spectrometer with a monochromatic Aluminum KaX-ray source (1486.6 eV) and under a vacuum of 10'8Torr. Casa XPS(Casa Software Ltd.) was used to analyze the obtained spectra. Film thicknesses were measured using a J. A. Woollam RC2 variable-angle spectroscopic ellipsometer (VASE). Incident angles were set at 55°, 65°, and 75° with a wavelength range of 193-1000 nm. The CompleteEASE software package (J. A. Woollam Co., Inc.) was used for fitting the optical constants and thicknesses via a three-layer model of (1) an Si substrate layer, (2) a 1.55-nm (native oxide) or 100 ± 1-nm (thermal oxide) layer, and finally (3) a polymer layer. Optical constants and thicknesses of polymeric layers were fitted using B-Spline or Gen-Osc models containing several Gaussian generalized oscillators. Water contact angles were determined using an in-house setup, and images were collected using a Windows PC webcam. Data was fit using the ImageJ contact angle plugin by Marco Brugnara. Micron-scale profiles and 3D scans were obtained using a Zeta-20 non-contact optical profilometer. Rheology data were obtained on a Discovery HR 30 from TA Instruments. Dynamic scanning calorimetry data were collected on a DSC 250 by TA Instruments.General Procedures for Surface-Initiated Polymerization Using SI-PET-RAFT

[0153] 4-Cyano-4[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid (CDTPA) was used as the CTA initiator. The synthesis of CDTPA and the preparation of CDTPA initiator monolayers were performed following protocols established in the inventors’ group. Inhibitors were removed from the monomers by filtration through a basic alumina column. The inhibitor-free monomer, RAFT CTA (i.e., CDTPA), and photocatalyst stock solution were mixed in a molar ratio of [monomer]: [CTA]: [photocatalyst] = 500: 1 :0.025 in a 4-mL vial to form the reaction mixture. The photocatalyst stock solution was a 1-mg / mL solution of zinc tetraphenylporphyrin (ZnTPP) in DMSO, which was stored in the dark to avoid photobleaching over time. To perform light-mediated SI-PET-RAFT, CDTPA-functionalized SiCh substrates (approx. 1.5 x 1.5 cm2) were coated with this reaction mixture using a pipette, covered with a glass coverslip, and placed approximately 1 cm below an LED light source (lmax = 405 nm; 2400 lux). After the desired irradiation time, the glass cover slip was removed, the wafers were thoroughly rinsed with dichloromethane and isopropanol, and the final substrates were dried under a stream of N2.Free Radical Polymerization of Terpolymers

[0154] 2-(acetoacetoxy)ethyl methacrylate (AAEMA), methyl methacrylate (MMA), and n- butyl acrylate (nBA) monomers were passed through a column of basic alumina to remove inhibitors. Subsequently, a flask was charged with the three monomers at a ratio of [AAEMA]: [MMA]: [nBA] = 5.4:44.6:50. Free radical polymerization was performed using azobisisobutyronitrile (AIBN) as the initiator (240.9 mg, 1.467 mmol) for the aforementionedmonomers (1.961 mL AAEMA [10.27 mmol], 5.962 mL MMA [55.73 mmol], 11.57 mL nBA [80.7 mmol]) in toluene (1 : 1 v / v of solvent to monomer) at 80 °C for 1 h. The resulting poly(AAEMA-co- MMA-co-nBA) terpolymer was precipitated using hexanes, filtered, and washed with hexanes, before the resulting white / transparent resin was dried in a vacuum oven at 75 °C overnight. The resulting polymers were characterized via gel permeation chromatography (GPC) and ’H nuclear magnetic resonance (NMR) spectroscopy.Spray Coating and Curing of Vitrimer Films

[0155] Tris(2-aminoethyl) amine (TREN) was dissolved in toluene in a 1 : 1 V / m solvent-to- polymer ratio. The dried poly(AAEMA-coMMA-co-nBA) terpolymer was dissolved in toluene in a 10: 1 V / m solvent-to-polymer ratio. The TREN solution was added dropwise to the terpolymer solution, in a 2: 1 ratio between the AAEMA monomer units and the TREN crosslinking agent. To facilitate spray coating (i.e., event crosslinking and vitrimer formation), the mixture was spray- coated onto polymer brush-functionalized substrates at a constant distance (FIG. 20) under room temperature and left to dry for at least one hour in open air. Finally, the spray-coated fdms were cured under vacuum and room temperature for 6 h, followed by 20 h under vacuum at 75 °C to obtain the final vitrimer coatings.Delamination Studies

[0156] Upon synthesis of vitrimer films on both polymer brush-functionalized substrates and unfunctionalized substrates, Soxhlet extraction of the substrates was performed using dichloromethane as a solvent. The solvent was heated just above its boiling point (39.6 °C) to 40 °C. After 24 h of Soxhlet extraction, the unfunctionalized substrates were evidently delaminated, revealing the surface of the blue silicon substrate, whereas the functionalized substrates were able to maintain their integrity via direct tethering of the vitrimer coating to the surface (see FIGS. 16A-B). The high degree of solvent exposure does cause minor swelling and non-uniformity of the vitrimer coating in the functionalized substrate; however, in comparison to the unfunctionalized substrate, the solvent resistance is improved.Supplemental InformationCharacterization Data for poly(AAEMA-co-MMA-co-nBA)

[0157] FIG. 7 depicts an exemplary 1H-NMR spectrum of a poly(AAEMA-co-MA-co-nBA) terpolymer synthesized via free radical polymerization. Azobisisobutyronitrile (AIBN) was used as the initiator.

[0158] FIG. 8 depicts an exemplary gel permeation chromatogram of a poly(AAEM A-co-M A- co-nBA) terpolymer synthesized via free radical polymerization. Azobisisobutyronitrile (AIBN) was used as the initiator.

[0159] FIG. 9 depicts exemplary differential scanning calorimetry (DSC) data for poly(AMB) / TREN CANs at a scan rate of 20 °C / min on heating, illustrating a glass transition temperature of Tg= 42 °C.

[0160] FIG. 10 depicts exemplary dynamic mechanical analysis (DMA) data for poly(AMB) / TREN CANs at a scan rate of 3 °C / min, with a 0.5% axial strain applied, under a frequency of 1 Hz.

[0161] FIG. 11 A depicts exemplary stress relaxation curves from a 0.3% step strain for the terpolymer vitrimer at 110 °C, 120 °C, 130 °C, and 140 °C, respectively.

[0162] FIG. 1 IB depicts exemplary data showing an Arrhenius relation of stress relaxation for poly(AMB) / TREN CANs.Determination of Topology Freezing Transition Temperature (Tv)

[0163] Tvwas estimated based on a viscosity of 106MPa s at Tv. This value was calculated from the activation energy for stress relaxation determined between 110 °C and 140 °C and the storage modulus, E’, from DMA at 150 °C (FIG. 10). The plateau E’ is 0.54 MPa. Assuming a Poisson’s ratio of n = 0.4 based on PMMA, the relaxation time at Tvis estimated as:

[0164] The temperature dependence of the stress relaxation time, t, between 1 10 °C and 140 °C was fit using:

[0165] to determine an activation energy of 92.5 kJ, which is then used to estimate Tvas 286.6 K from the relaxation time at T = Tvdescribed above (T(TV) = 5.19 x 106s).Synthesis and Characterization of Polymer Brush filmsSynthetic Pathway towards Poly(AAEMA-co-MA- nBA) Polymer Brushes

[0166] FIG. 12 depicts a schematic illustration describing the synthesis of poly(AAEMA-co- MA-co-nBA) polymer brushes from RAFT initiator-functionalized SiCE substrates. SiCh was initially activated using Piranha treatment to generate surface-bound hydroxyl groups. 4-cyano- 4[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid (CDTPA) was selected as the RAFT CTAinitiator. SI-PET -RAFT was used to polymerize the three monomers, i.e., AAEMA, MA, and nBA, in DMSO, with zinc tetraphenylporphyrin (ZnTPP) (1 mg / mL) as a photocatalyst.X-ray Photoelectron Spectroscopy of Poly(AAEMA-co-MMA-co-nBA)

[0167] FIG. 13 depicts an exemplary high-resolution carbon Cis X-ray photoelectron spectrum of poly(AAEMA-co-MMA-co-nBA) polymer brushes and corresponding curve fits of three distinct carbon environments: R3C-CR3, R3C-O-RC=O, and O-RC=O. Table 1 summarizes parameters from these curve fits.Table 1 . Fitting Parameters of High-Resolution Carbon Ci s X-ray Photoelectron Spectrum of Poly(AAEMA-co-MMA-co-nBA) Polymer Brushes.

[0168] FIG. 14A depicts a schematic illustration of the chemical structure of polymer brushes including a bipolymer of AAEMA and 77-hexyl methacrylate (HMA), i.e., poly(AAEMA-co-HMA), synthesized via SI-PET-RAFT.

[0169] FIG. 14B depicts corresponding kinetics data of the poly(AAEMA-co-HMA) polymer brushes as shown in FIG. 14A, with polymer brush thickness plotted as a function of irradiation / reaction time.Engineering and Characterization of Vitrimer coatingsX-ray Photoelectron Spectroscopy of Vitrimer Coatings

[0170] FIG. 15 depicts an exemplary high-resolution carbon Cis X-ray photoelectron spectrum of poly(AAEMA-co-MA-co-nBA) polymer brushes that were spray coated with a solution of poly(AAEMA-co-MA-co-nBA) and TREN. The curve fits show three distinct carbon environments: R3C-CR3, C-(N,O), and O-RC=O. Table 2 summarizes parameters from these curve fits.Table 2. Fitting Parameters of High-Resolution Carbon Cis X-ray Photoelectron Spectrum of Poly(AAEMA-co-MMA-co-nBA) Polymer Brushes Spray-Coated with a Solution of Poly(AAEMA- co-MA-co-nBA) and TREN.Delamination Studies

[0171] Comparing unfunctionalized and functionalized wafers that were both cured with the vitrimer reveals that there are linkages between the polymer brush and polymer coating. Upon synthesis of vitrimer films on both polymer brush-functionalized substrates and unfunctionalized substrates, Soxhlet extraction of the substrates was performed using dichloromethane as a solvent. The solvent was heated just above its boiling point (39.6 °C) to 40 °C. After 24 h of Soxhlet extraction, the unfunctionalized substrates were evidently delaminated, revealing the surface of the blue silicon substrate, whereas the functionalized substrates were able to maintain their integrity via direct tethering of the vitrimer coating to the surface. The high degree of solvent exposure does cause swelling and non-uniformity of the vitrimer coating in the functionalized substrate; however, in comparison to the unfunctionalized substrate, the solvent resistance is improved.

[0172] FIG. 16A depicts an exemplary photograph of an unfunctionalized silicon wafer after synthesis of a vitrimer coating, curing, and Soxhlet extraction with dichloromethane at 40 °C for 24 h.

[0173] FIG. 16B depicts an exemplary photograph of a p(AMB) polymer brush-functionalized silicon wafer after synthesis of a vitrimer coating, curing, and Soxhlet extraction with di chloromethane at 40 °C for 24 h. Compared to FIG. 16A, the functionalized wafer in FIG. 16B demonstrates an improved solvent resistance via preservation of the coating after Soxhlet extraction. Self-Healing Tests Profdometry Data

[0174] Optical profdometry was used to confirm the complete self-healing and to elucidate the healing kinetics of these coatings. Due to the nature of optical profdometry taking hundreds of images at different heights over time, viewing the 3-dimensional process of healing is not possible in situ. As a result, the primary method of data collection for these experiments was start-stop experiments. A hot plate was set to a desired temperature (e.g. 50 °C, 100 °C, 140 °C, etc.), the substrate was placed on top of the hot plate with tweezers, and a non-contact infrared thermometer was used to monitor the temperature of the coating. After a variety of time points for different trials,the substrate would then be placed quickly onto a block of copper at T ~ 22 °C (functioning as a heat sink) to avoid excess heat becoming a source of error.

[0175] FIGS. 17A-B depict exemplary screenshots directly from the Zeta-20 Optical Profilometer before and after self-healing at 130 °C for two minutes. Left: 13:37:09 on 25 July 2023. Right: 13:43:11 on 25 July 2023.

[0176] FIGS. 18A-C depict multiple exemplary snapshots of scratch profiles at various time intervals at 70 °C, 100 °C, and 120 °C, respectively.

[0177] FIG. 19A depicts exemplary healing kinetics of scratches as a function of time at 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C, and 130 °C, respectively.

[0178] FIG. 19B depicts exemplary data comparing small strain stress relaxation from a 0.3% strain in a rheometer (right axis) with the depth recovery of a scratch (left axis) at 130 °C. The scratches heal faster than the stress relaxes in the vitrimer.

[0179] FIG. 19C depicts exemplary data showing slow healing of scratch at ambient temperature.Degradation of Coatings at High Temperatures

[0180] FIG. 20 depicts an exemplary photograph of p(AMB) / TREN vitrimer coating on a polymer brush-functionalized substrate after heating to T > 200 °C. Self-healing was initially successful on this coating at a lower temperature, but as degradation of the coating worsened (evidenced by a change in color from clear to a brownish-green), scratches would only partially heal, if at all, or would leave scars.Coating Techniques Airbrush Deposition

[0181] An airbrush was used to deposit the vitrimer coating onto the substrates prior to curing them. The airbrush used for these experiments has a volumetric flowrate of 130 pL / s, using deionized water as a standard. The p(AMB) (2.68 g) was dissolved in toluene (27.0 mb). Once completely dissolved, TREN (0.090 mL, 0.601 mmol), dissolved separately in toluene (3.0 mL), was added dropwise to the polymer solution. The airbrush was prepped by cleaning with and spraying with toluene. The vitrimer solution was then added to the airbrush, and the airbrush was secured with a clamp to maintain a constant distance. Distances of 1 cm, 3 cm, 5 cm, and 10 cm were tested (using various solvents). Low boiling solvents, including acetone and dichloromethane, did not deposit successfully at larger distances. Higher boiling point solvents, such as toluene and tetrahydrofuran (THF), were able to deposit uniform coatings for each of the tested distances. Afterperforming one deposition pass on a substrate, the solution was allowed to settle for 3-5 s prior to performing a second deposition. This method was successful in creating coatings between 10-100 pm thick for the bulk of the data collection in this work, although thicker coatings, up to 500 pm were also successfully created. After deposition, the films were allowed to dry for at least 1 h in open air, at which point they were stored under vacuum for 6 hours and heated under vacuum for 20 h.

[0182] FIG. 21 depicts an exemplary photograph illustrating the experimental spray-coating approach at a 10-cm spraying distance. 1.5 cm * 1.5 cm blue silicon wafers are the substrates visible on the cardboard; the upper wafer is unfunctionalized, whereas the lower wafer is functionalized with a ~p(AMB) polymer brush.Alternatively Tested Coating Methods

[0183] Prior to enlisting airbrush coating as the primary method of deposition for synthesis of the vitrimer coatings, drop coating was found to also be suitable to facilitate self-healing and prevention of delamination. Airbrush coating provided a more uniform surface, and thus drop coating was not chosen for these experiments. The experimental method to synthesize drop-coated wafers was to dissolve the polymer in toluene (1 :3 mass to volume ratio of polymer to solvent), and the same 2: 1 incorporation of AAEMA units to TRENT was added to this solution. The polymer- brush functionalized substrates were placed on a glass slide which was then placed on a hot plate set to 55°C. The vitrimer solution was added dropwise, allowing the toluene to fully evaporate before adding additional drops of the mixture. The substrates were then cured under vacuum at 75 °C for 24 h.

[0184] FIG. 22 depicts an exemplary photograph of p(AAEMA-co-HMA) (including 35 mol% AAEMA) crosslinked with TREN deposited (via drop coating) on p(AAEMA-co-HMA) polymer brush-functionalized silicon wafers. These samples successfully self-healed. The photograph shown is after a cycle of damage and autonomous recovery.

[0185] Another one of the initial methods of deposition tested for this body of work was blade coating. The granular and nonuniform appearance of these coatings ruled out this deposition method for the purposes of this work. To synthesize these coatings, the polymer was first dissolved in a 5: 1 ratio of solvent (toluene) to polymer mass, and then the 2: 1 ratio of AAEMA units to TREN was added. This was allowed to dry in open air for 12 h, cured under vacuum at room temperature for 4 hours, then cured at 75 °C for 24 h. The resulting material was then ground with a mortar and pestle, mixed into a paste with toluene, and spread across the polymer-brush functionalized substrates (heldon the sides with non-soluble tape) with a glass pipette. These coatings were further cured for another 24 h. Self-healing was not observed on these coatings.

[0186] FIG. 23 depicts an exemplary photograph of p(AAEMA-co-HMA) polymer brush- functionalized silicon wafers with an attempt at blade coating the vitrimer on the surface. Self-Healing Demonstration

[0187] FIG. 24 depicts an exemplary photograph of p(AMB) / TREN CANs on unfunctionalized glass (left) and p(AMB) polymer brush-functionalized glass (right) before and after self-healing.

[0188] The foregoing has been a detailed description of illustrative embodiments of the invention. Various modifications and additions can be made without departing from the spirit and scope of this invention. Features of each of the various embodiments described above can be combined with features of other described embodiments as appropriate in order to provide a multiplicity of feature combinations in associated new embodiments. Furthermore, while the foregoing describes a number of separate embodiments, what has been described herein is merely illustrative of the application of the principles of the present invention. Additionally, although particular methods herein can be illustrated and / or described as being performed in a specific order, the ordering is highly variable within ordinary skill to achieve methods, systems, and software according to the present disclosure. Accordingly, this description is meant to be taken only by way of example, and not to otherwise limit the scope of this invention.

[0189] Exemplary embodiments have been disclosed above and illustrated in the accompanying drawings. It will be understood by those skilled in the art that various changes, omissions and additions can be made to that which is specifically disclosed herein without departing from the spirit and scope of the present invention.

Claims

CLAIMS1. A self-healing composition of matter, the composition comprising: a covalent adaptive network, comprising: a primer layer covalently tethered to a surface; and a coated polymer crosslinked with the primer layer through a reversible covalent linkage.

2. The composition according to claim 1, wherein the covalent adaptive network comprises a vitrimer.

3. The composition according to claim 1 or 2, wherein the primer layer comprises a terpolymer of 2-(acetoacetoxy)ethyl methacrylate, methyl methacrylate, and / / -butyl acrylate or a bipolymer of 2-(acetoacetoxy)ethyl methacrylate and / / -hexyl methacrylate.

4. The composition according to claim 3, wherein the terpolymer of the primer layer comprises at least 1 mol% and no greater than 60 mol% of 2-(acetoacetoxy)ethyl methacrylate.

5. The composition according to claim 3 or 4, wherein the terpolymer of the primer layer comprises at least 35 mol% and no greater than 55 mol% of methyl methacrylate.

6. The composition according to any one of claims 3-5, wherein the terpolymer of the primer layer comprises at least 40 mol% and no greater than 60 mol% of / / -butyl acrylate.

7. The composition according to any one of claims 3-6, wherein the terpolymer of the primer layer comprises 2-(acetoacetoxy)ethyl methacrylate, methyl methacrylate, and / / -butyl acrylate in a molar ratio of approximately 5:45:50.

8. The composition according to any one of claims 1-7, wherein the primer layer comprises a polymer brush layer having a thickness of no greater than 300 nm.

9. The composition according to claim 8, wherein the polymer brush layer has a thickness of no greater than 200 nm.

10. The composition according to any one of claim 8 or 9, wherein the polymer brush layer has a thickness of approximately 180 nm.

11. The composition according to any one of claims 1-10, wherein the surface comprises a surface of one or more materials selected from a group consisting of silica, glass, ceramic, polymer, resin, metal, and metal alloy.

12. The composition according to any one of claims 1-11, wherein the coated polymer comprises a terpolymer of 2-(acetoacetoxy)ethyl methacrylate, methyl methacrylate, and / / -butyl acrylate or bipolymer of 2-(acetoacetoxy)ethyl methacrylate and / / -hexyl methacrylate.

13. The composition according to any one of claims 1-12, wherein the coated polymer has a number average molecular weight of at least 20 kg / mol and no greater than 100 kg / mol.

14. The composition according to claim 13, wherein the number average molecular weight of the coated polymer is approximately 39.8 kg / mol.

15. The composition according to any one of claims 1-14, wherein the coated polymer comprises at least 1 mol% and no greater than 10 mol% of 2-(acetoacetoxy)ethyl methacrylate.

16. The composition according to any one of claims 1-15, wherein the coated polymer comprises approximately 5 mol% of 2-(acetoacetoxy)ethyl methacrylate.

17. The composition according to any one of claims 1-16, wherein the coated polymer has a dispersity of at least 2.0 and no greater than 5.0.

18. The composition according to any one of claims 1-17, wherein the dispersity of the coated polymer is approximately 3.0.

19. The composition according to any one of claims 1-18, wherein the reversible covalent linkage comprises one or more members selected from a group consisting of a vinylogousurethane group, a vinylogous urea group, a cyclohexenyl group, a 1,2,3-triazolium group, an ester group, a siloxane group, an olefin group, a disulfide group, a carbamate group, a trithiocarbonate group, an alkoxyamine group, and an imine group.

20. The composition according to any one of claims 1-19, wherein the composition has a glass transition temperature (7g) of at least 30 °C and no greater than 80 °C.

21. The composition according to claim 20, wherein the 7 is approximately 42 °C.

22. The composition according to any one of claims 1-21, wherein the composition has a topology freezing transition temperature (A) of at least 10 °C and no greater than 25 °C.

23. The composition according to claim 22, wherein the Tvis approximately 13.5 °C.

24. The composition according to any one of claims 1-23, wherein the composition self-heals an incision therein within 60 s under a temperature of at least 160 °C and no greater than 200 °C.

25. A method of preparing the composition according to any one of claims 1-24, the method comprising: preparing the primer layer tethered to the surface; and applying a polymer to the primer layer, wherein at least one portion of the polymer crosslinks with the primer layer through a reversible covalent linkage.

26. The method according to claim 25, wherein preparing the primer layer comprises: immobilizing a chain transfer agent (CTA) onto the surface; and synthesizing a polymer brush layer using the immobilized CTA.

27. The method according to claim 26, wherein the CTA comprises one or more members selected from a group consisting of a dithioester, a dithiobenzoate, a dithiocarbamate, a trithiocarbonate, and a xanthate.

28. The method according to claim 26, wherein the CTA comprises 4-cyano- 4[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid (CDTPA).

29. The method according to any one of claims 26-28, wherein synthesizing the polymer brush layer comprises synthesizing the polymer brush layer using surface-initiated polymerization.

30. The method according to claim 29, wherein the surface-initiated polymerization comprises reversible addition-fragmentation chain transfer polymerization (RAFT).

31. The method according to claim 30, wherein the RAFT comprises surface-initiated photoinduced electron transfer-reversible addition-fragmentation chain transfer polymerization (SI-PET-RAFT).

32. The method according to any one of claims 25-31, wherein the primer layer is polymerized using a photocatalyst.

33. The method according to claim 32, wherein the photocatalyst comprises a coordination complex.

34. The composition according to claim 33, wherein the coordination complex comprises a substituted or unsubstituted zinc tetraphenylporphyrin (ZnTPP).

35. The composition according to any one of claims 32-34, wherein the photocatalyst is illuminated using blue light.

36. The method according to any one of claims 25-35, further comprising synthesizing the polymer to be coated using free radical polymerization.

37. The method according to claim 36, wherein the free radical polymerization uses one or more initiators selected from a group consisting of azobisisobutyronitrile (AIBN), 1,1’- azobis(cyclohexanecarbonitrile) (ABCN), di- / -butyl peroxide (DTBP), benzoyl peroxide (BPO), methyl ethyl ketone peroxide (MEKP), acetone peroxide (APEX), a peroxy di sulfatesalt, a carbon halide, a benzenesulfonic acid ester, an alkyl sulfonium salt, 2,2’-azobis[2-(2- imidazolin-2-yl)propane] dihydrochloride, / -butyl hydroperoxide (TBHP), cumene hydroperoxide, dicumyl peroxide, and ammonium persulfate (APS).

38. The method according to any one of claims 25-37, wherein applying the polymer comprises spray coating a solution comprising the polymer.

39. The method according to claim 38, wherein the solution further comprises a crosslinking agent.

40. The method according to claim 39, wherein the crosslinking agent comprises tris(2- aminoethyl) amine (TREN) or / w-xylylenediamine.

41. The method according to claim 39 or 40, wherein: the polymer to be coated comprises 2-(acetoacetoxy)ethyl methacrylate monomer units; and the 2-(acetoacetoxy)ethyl methacrylate monomer units and the crosslinking agent has a molar ratio of approximately 2: 1.

42. The method according to any one of claims 38-41, wherein applying the solution comprises spray coating the solution using an airbrush spray jet.

43. The method according to claim 42, wherein the airbrush spray jet is operated at a flow rate of 100-300 pL / s.

44. The method according to claim 43, wherein the flow rate is approximately 130 pL / s.

45. A self-healing composition of matter prepared using the method according to any one of claims 25-44.

46. A method of preparing a self-healing surface, the method comprising applying or tethering to a surface the composition according to any one of claims 1-45.

47. The method according to claim 46, further comprising drying or curing the composition to produce a coating layer.

48. Use of the composition according to any one of claims 1-47 for preparing a scratch-resistant, solvent-resistant, anti-fouling, or anti-corrosion coating layer.

49. A coating material comprising the composition according to any one of claims 1-47.

50. A coated surface comprising: a substrate; and the composition according to any one of claims 1-47 applied or tethered to the substrate.

51. An article of manufacture comprising the composition according to any one of the claims 1- 47.

52. A method of increasing scratch resistance, corrosion resistance, solvent resistance, or adhesion resistance of a surface, the method comprising applying or tethering to a substrate the composition according to any one of claims 1-47.

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