(327i) Comparison of Long-Term Stability of Initiating Monolayers in Surface-Initiated Controlled Radical Polymerizations

Applications for surface-tethered macromolecules (polymer brushes) range from marine paints to biomedical devices to flame-retardant and electroactive coatings. The reproducibility of polymer brush synthesis via surface-initiated (SI) controlled radical polymerization (SI-CRP) is interrogated. Experiments compare the stability of initiating monolayers for SI reversible addition-fragmentation chain transfer polymerization (SI-RAFT) and SI atom transfer radical polymerization (SI-ATRP). Initiator-functionalized substrates were stored under various conditions and grafting densities of the resulting polymer brush films were determined via in situ ellipsometry swelling experiments. Decomposition of one of the examined SI-RAFT initiators resulted in limited reproducibility for polymer brush surface modification. In contrast, initiators for SI-ATRP showed excellent stability and reproducibility. While both techniques bring inherent benefits and limitations, the described findings will help scientists choose the most efficient technique for their goals in chemical and topographical surface modification.