Department of Chemical and Biological Engineering, University of Colorado Boulder, Campus Box 596, CO, 80309, USA.
Department of Chemical Engineering and Chemistry, Technische Universiteit Eindhoven, P.O. Box 513, 5600, MB, Eindhoven, The Netherlands.
Adv Mater. 2017 May;29(17). doi: 10.1002/adma.201606509. Epub 2017 Feb 24.
Photoactivated reversible addition fragmentation chain transfer (RAFT)-based dynamic covalent chemistry is incorporated into liquid crystalline networks (LCNs) to facilitate spatiotemporal control of alignment, domain structure, and birefringence. The RAFT-based bond exchange process, which leads to stress relaxation, is used in a variety of conditions, to enable the LCN to achieve a near-equilibrium structure and orientation upon irradiation. Once formed, and in the absence of subsequent triggering of the RAFT process, the (dis)order in the LCN and its associated birefringence are evidenced at all temperatures. Using this approach, the birefringence, including the formation of spatially patterned birefringent elements and surface-active topographical features, is selectively tuned by adjusting the light dose, temperature, and cross-linking density.
光活化可逆加成-断裂链转移（RAFT）基动态共价化学被引入液晶网络（LCN）中，以促进取向、畴结构和双折射的时空控制。基于 RAFT 的键交换过程导致应力松弛，可在多种条件下使用，使 LCN 在照射后能够达到近平衡结构和取向。一旦形成，并且在没有随后触发 RAFT 过程的情况下，LCN 及其相关双折射的（无序）在所有温度下都有证据表明。通过这种方法，通过调整光剂量、温度和交联密度，可以有选择地调节双折射，包括空间图案化双折射元件和表面活性形貌特征的形成。
