Surface-Initiated Photoinduced ATRP: Mechanism, Oxygen Tolerance, and Temporal Control during the Synthesis of Polymer Brushes

Surface-initiated, photoinduced atom transfer radical polymerization (SI-photoATRP) enables the controlled and rapid synthesis of compositionally diverse polymer brushes over large areas by employing very small reaction volumes under ambient conditions and without the need for prior deoxygenation of monomer mixtures. The concentration of copper species and the type and content of amine-based ligands determine the mechanism of SI-photoATRP, regulate the kinetics of polymer-brush growth, and govern the tolerance of this polymer-grafting method toward oxygen. Despite mechanistic analogies with the corresponding solution processes, the intrinsic, highly confined nature of SI-photoATRP leads to significant differences from polymerizations within homogeneous systems. This is especially important to attain controlled/living polymerization and temporal control over polymer-brush growth by using UV light as a trigger.