Matthew J. Feeney
A number of light-responsive materials have utilized photochromic moieties, capable of undergoing a change in absorbance upon exposure to light. One class of photochromes, spiropyran, has been incorporated into polymeric platforms to realize various functions, including sensing and optical data storage. However, many of the materials reported in this field are water insoluble, which limits their application in biological systems. In this work, we have prepared numerous spiropyran-containing acrylic polyelectrolytes through living and standard radical polymerization means. The choices of both the specific spiropyran monomer and the inert comonomer had distinct effects on material properties. Specifically, the pKa and photo-isomerization rates of the protonated merocyanine (MCH) species in each polymer were observed to be dependent on two variables: the charge of the photoinert comonomer, and the substituent on the chromene ring of the spiropyran monomer. By tuning these variables, a wide range of polymeric properties were attainable. Additionally, these materials show promise for the future development of charge shifting and photoacid materials.