Fabrication of multifunctional surfaces with complexity approaching that found in nature requires the application of a modular approach to surface engineering. We describe a versatile post-polymerization modification strategy to synthesize multifunctional polymer brush surfaces via combination of surfaceinitiated photopolymerization (SIP) and orthogonal thiol-click reactions. Specifically, we demonstrate two routes to multifunctional brush surfaces: in the first approach, alkyne-functionalized homopolymer brushes are modified with multiple thiols via a statistical, radical-mediated thiol-yne coclick reaction; and in the second approach, statistical copolymer brushes carrying two distinctlyaddressable reactive moieties are sequentially modified via orthogonal base-catalyzed thiol-X (where X represents an isocyanate, epoxy, or a-bromoester) and radical-mediated thiol-yne reactions. In both cases, we show that surface properties, in the form of wettability, can be easily tuned over a wide range by judicious choice of brush composition and thiol functionality.

We report a simple and versatile method for the fabrication of superhydrophobic inorganic-organic thiol-ene coatings via sequential spray-deposition and photopolymerization under ambient conditions. The coatings are obtained by spray-deposition of UV-curable hybrid inorganic-organic thiol-ene resins consisting of pentaerythritol tetra(3-mercaptopropionate) (PETMP), triallyl isocyanurate (TTT), 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (TMTVSi), and hydrophobic fumed silica nanoparticles. The spray-deposition process and nanoparticle agglomeration/dispersion provide surfaces with hierarchical morphologies exhibiting both micro- and nanoscale roughness. The wetting behavior, dependent on the concentration of TMTVSi and hydrophobic silica nanoparticles, can be varied over a broad range to ultimately provide coatings with high static water contact angles (>150°), low contact angle hysteresis, and low roll off angles (<5°). The cross-linked thiol-ene coatings are solvent resistant, stable at low and high pH, and maintain superhydrophobic wetting behavior after extended exposure to elevated temperatures. We demonstrate the versatility of the spray-deposition and UV-cure process on a variety of substrate surfaces including glass, paper, stone, and cotton fabric.

Superamphiphobic surfaces, exhibiting high contact angles and low contact angle hysteresis to both water and low surface tension liquids, have attracted a great deal attention in recent years because of the potential of these materials in practical applications such as liquid-resistant textiles, self-cleaning surfaces, and antifouling/anticorrosion coatings. In this work, we present a simple strategy for fabricating of superamphiphobic coatings based on photopolymerization of hybrid thiol-ene resins. Spray-deposition and UV photopolymerization of thiol-ene resins containing hydrophobic silica nanoparticles and perfluorinated thiols provide a multiscale topography and low-energy surface that endows the surface with superamphiphobicity. The wettability and chemical composition of the surfaces were characterized by contact-angle goniometry and X-ray photoelectron spectroscopy, respectively. The hierarchical roughness features of the thiol-ene surfaces were investigated with field-emission scanning electron microscopy. Droplet impact and sandpaper abrasion tests indicate the coatings respectively possess a robust antiwetting behavior and good mechanical durability.

Functional, micropatterned and multicomponent polymer brush surfaces can be rapidly fabricated via base-catalyzed thiol-isocyanate ''click'' reactions.

In this work, we report the synthesis of photocurable, ternary polymer networks prepared by incorporating dopamine acrylamide (DAm) into a cross-linked thiol−ene network based on pentaerythritol triallyl ether (APE) and pentaerythritol tetra(3-mercaptopropionate) (PETMP). We systematically evaluate the effect of DAm, in the nonoxidized catechol form, on photopolymerization kinetics and thermal, thermomechanical, and mechanical properties of the modified thiol−ene networks. We show that while DAm only affects photopolymerization kinetics at high concentrations, the presence of the catechol moiety significantly increases the glass transition temperature of the networks across the compositional range (0−50 mol % DAm) due to hydrogen bonding interactions between the catechol and various hydrogen bonding acceptors (ethers, amides, esters) within the network, despite an obvious decrease in cross-link density with increasing concentration of the monofunctional acrylamide. Similarly, trends in the mechanical properties of the DAm−APE−PETMP networks reflect the interplay that exists between competing network design parameters, including the catechol hydrogen bonding interactions and the decrease in cross-link density derived from the use of a monofunctional acrylamideboth of which simultaneously influence network properties. Additionally, we report improved macroscopic adhesion of DAm−APE−PETMP coatings to a range of substratesincluding glass, aluminum, steel, and marbleby systematically varying the amount of DAm in the network. Adhesion of the DAm−APE−PETMP coatings were evaluated using two methods, including pull-off and crosshatch adhesion tests.