Novel Stimuli-Responsive Polyelectrolyte Brushes

Abstract

Novel stimuli-responsive polyelectrol poly(N-benzyl-N'-(4-vinylbenzyl)-4,4'-bipyridium dichloride) or P(BpyClCl), brushes were prepared from the benzyl-chloride-immobilized SiO(2) nanoparticles via surface-initiated atom transfer radical polymerization (ATRP). The dicationions (BV(2+)) of the P(BpyClCl) brushes can be reduced by UV irradiation to become radical monocations (BV(+.)), which can oxidize back to the original BV(2+) State by exposure to air. The fast switching between dicationic and monocationic states of the P(BpyClCl) brushes oil the SiO(2) nanoparticles can be used as the physically controllable means for the reduction of metal ions (such as Au, Pt, and bimetallic Au/Pt ions) without the need for any added metal reduction agents.