Polymer Brush-Functionalized Surfaces with Reversible, Precisely Controllable Two-Way Responsive Wettability

This paper is the first to present a facile method of fabricating intelligent surfaces with reversible, precisely controllable, two-way responsive wettability. The ABC-type block copolymers of tert-butyl methacrylate (tBMA), 2-hydroxyethyl methacrylate (HEMA), and 2-(diisopropylamino)ethyl methacrylate (DPAEMA) were synthesized through living radical polymerization mediated by a reversible addition–fragmentation chain transfer (RAFT) process and then grafted onto acyl chloride group-functionalized SiO2 films to produce V-shaped PDPAEMA-b-PHEMA-b-PtBMA brush-grafted SiO2 films. After hydrolysis, V-shaped polymer brushes with two arms of PDPAEMA and PMAA were produced. Because the PMAA and PDPAEMA segments were highly and independently responsive to pH values, the as-obtained films not only exhibited reversible, one-to-one, precisely controllable wettability but also two-way response behavior as pH value increased.