P(BMA-co-HEMA-spiropyran) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization of butyl methacrylate (BMA) and 2-(trimethylsilyloxy)-ethyl methacrylate (HEMA-TMS), removal of the TMS-protective groups, and the polymer analogous esterification of the hydroxyethyl side chains with a spiropyran containing a carboxylic acid group. UV-induced conformational changes of the synthesized macromolecules and low-molecular-weight spiropyran molecules were studied. Rate constants and half-life times of the ring closure reaction from zwitterionic merocyanine to the spiropyran species were determined in the presence and absence of mica-dispersed particles in toluene both with the free spiropyran and the polymer-bound spiropyran. Scanning force microscopy was used to visualize the conformation of spiropyran-decorated single macromolecular chains and agglomerated polymer-bound merocyanine adsorbed on mica. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1274-1283, 2009