Azo-Polymer Janus Particles Assembled by Solvent-Induced Microphase Separation and Their Photoresponsive Behavior

作者：Zhou, Xinran; Chen, Shouping; Liu, Bingyang; Wang, Xiaogong^*

来源：Chemistry-An Asian Journal, 2016, 11(23): 3443-3448.

DOI：10.1002/asia.201601259

• azo compounds
• deformation
• Janus particles
• nanoparticles
• self-assembly

We report the successful fabrication of photoresponsive Janus particles (JPs) composed of an epoxy-based azo polymer and poly(methyl methacrylate) (PMMA). Two representative azo polymers, of which one polymer (BP-AZ-CN) has cyano groups as electron-withdrawing substituents on the azobenzene moieties and the other polymer (BP-AZ-CA) has carboxyl groups as the electron-withdrawing substituents, were adopted for the investigation. The nanoscaled JPs, with a narrow size distribution and different azo polymer/PMMA ratios, were fabricated through self-assembly in solution and as dispersions. Upon irradiation with linearly polarized light (lambda=488 nm), two types of photoresponsive behavior were observed for JPs in the solid state. For JPs composed of BP-AZ-CN and PMMA, the light irradiation caused the azo-polymer component to be stretched along the light polarization direction. Conversely, for JPs composed of BP-AZ-CA and PMMA, the azo-polymer component became separated from PMMA component under the same irradiation conditions. These observations are valuable for a deeper understanding of the nature of self-assembly and photoinduced mass-transport at the nanometer scale.

• 出版日期2016-12-6
• 单位清华大学