Q-sized CdS: Synthesis, characterization, and efficiency of photoinitiation of polymerization of several vinylic monomers

The effect of temperature, stirring, excess cadmium, solvent viscosity, and dielectric strength on Q-sized CdS semiconductors in nonaqueous solvents is examined. Q-sized semiconductors have higher photopolymerization quantum yields than bulk sized CdS, ZnO, and TiO2 and need hole scavenging by the solvent to occur. There is also a correlation between monomer reactivity toward polymerization and its Alfrey and Price Q and e values. There is also a correlation between semiconductor photoinitiation efficiency and conduction band electron reduction potential. Based on this, anionic initiation followed by free radical propogation has been proposed. 42 refs., 6 figs., 7 tabs