Spatiotemporally controlled formation of two-component counterpropagating lateral graft density gradients of mixed polymer brushes on planar an surfaces

A facile method to template mixed polymer-brush gradients onto a An surface using a grafting-from atom-transfer radical polymerization coupled with an in-plane electrochemical-potential gradient is developed and studied (see figure), PNIPAAm: poly(N-isopropylacrylamide); PHEMA: poly(2-hydroxyethyl methacrylate). Polymer-brush gradients can be easily formed with tunable slope and transition-region width in a wide range of physical sizes by combining these methods.