Search

Photopolymerization of acrylamide in aqueous solutions induced by visible light (λ>400 nm) absorbed by colloidal particles of CdxZn 1-x S, Fe2O3 and graphene oxide is reported. Depending on the photoinitiator nature, primary radicals are generated by monomer reduction with conduction band electrons (CdxZn 1-x S), monomer oxidation by the valence band holes (Fe2O3) or by interaction between monomer and free radicals photoeliminated from graphene oxide. The photopolymerization rate increases proportionally to the conduction band potential of CdxZn 1-x S nanoparticles that depends on their composition. The Fe2O3-initiated acrylamide photopolymerization proceeds with comparable effectiveness in both deaerated and air-exposed aqueous solutions, the feature differing drastically from typical organic photoinitiators. On the basis of kinetic parameters the photopolymerization process was found to be of the chain free radical character with a principal chain termination route being macro-radicals recombination. The kinetic data also indicate a possibility of participation of the CdxZn 1-x S nanoparticles and graphene oxide in the chain termination. [ABSTRACT FROM AUTHOR]