A Click Chemistry Strategy for the Synthesis of Efficient Photoinitiators for Two‐Photon Polymerization
Irene Henning, Adam W. Woodward, Graham A. Rance, Benjamin T. Paul, Ricky D. Wildman, Derek J. Irvine, Jonathan C. Moore
Abstract
Abstract It is reported that efficient photoinitiators, suitable for two‐photon polymerization, can be obtained using the copper catalyzed azide/alkyne cycloaddition reaction. This click chemistry strategy provides a modular approach to the assembly of photoinitiators that enables the rapid variation of key fragments to produce photoinitiators with desirable properties. To assess the performance of the first‐in‐class photoinitiators generated by this approach, a screening method is developed to enable the rapid determination of polymerization and damage thresholds in numerous photoresists during two‐photon polymerization. The degree of consumption of vinyl groups (DC) and homogeneity of the polymerization are further assessed by micro‐Raman spectroscopy. Finally, more complex structures are fabricated to demonstrate that the efficient two‐photon polymerization of stable 3D microarchitectures can be achieved using triazole‐based photoinitiators.