Functionalization of Metal Surface via Thiol-Ene Click Chemistry: Synthesis, Adsorption Behavior, and Postfunctionalization of a Catechol- and Allyl-Containing Copolymer.

Surface functionalization tailors the interfacial properties without impacts on the mechanical strength, which is beneficial for industry and daily applications of various metallic materials. Herein, a two-step surface functionalization strategy, (1) catechol-mediated immobilization of clickable agent and (2) postfunctionalization based on thiol-ene click reaction, is achieved using a copolymer, namely poly[2-(methacryloyloxy)ethylundec-10-enoate]--(-(3,4-dihydroxyphenethyl) methacrylamide) [P(MEUE--DPMAm)]. To reduce the potential side reactions of allylic double bonds in allyl methacrylate during the polymerization, the MEUE are designed and synthesized with better control over the polymer chain growth. The surface functionalization via the two-step method is demonstrated using various thiols, e.g., hydrophobic, hydrophilic, and polymeric thiols under room conditions. Additionally, the hydrophobic-thiol-functionalized anodic aluminum oxide is found to be a candidate for the oil/water separation with a separation efficiency of ∼99.2%. This surface modifier provides practical insights into the further design of functional materials.