Importance of end-group structure in controlling the interfacial activity of polymer-coated nanoparticles

The critical importance of controlling the molecular structure of the core shell type nanoparticles was investigated by observing the change in nanoparticle position within a polymer matrix. Two different polymers were synthesized by living anionic polymerization and RAFT polymerization, to test the importance of the steric environment and nature of the end group. A PS chain was synthesized by anionic polymerization and terminated by reaction with ethylene sulfide to give desired primary thiol end group. The corresponding secondary derivative which has a secondary thiol end group adjacent to the phenyl ring, was prepared by RAFT polymerization followed by amidation of the terminal dithio ester. Polymeric ligands derived from RAFT polymers which contain secondary thiol groups were found not to be sufficiently surface active to screen further interactions with the Au surface.