Controlling Electroosmotic Flow in Microchannels with pH-Responsive Polyelectrolyte Multilayers

Abstract

A polyelectrolyte multilayer coating comprising acrylic acid or imidazole units afforded precise control over the rate and direction of electroosmotic flow within fused silica capillaries. Morphological changes accompanying the pH-induced switching of surface charge were minimized by diluting the pH-responsive polyelectrolyte with permanently charged polymer. Electroosmotic stability over many runs was demonstrated