A Study of Azobenzene-Polymers and Their Photofluidic Movement

초록

Photo-responsive polymers, which demonstrate physical and chemical changes upon light irradiation at a certain wavelength, have been a subject of numerous research studies due to their potential applications in photo-optical media, photo-switches, photo-mechanical systems, micro/nano patterning and nonlinear optical media. Azobenzene and its derivatives are the most widely used photo-responsive chromophores in these polymeric networks, owing to their distinct optical properties. Azobenzene polymers exhibit a unique phenomenon called anisotropic photofluidic movement, which is triggered by their photo-isomerization characteristics. This phenomenon is observed at temperatures below the glass transition temperature of the polymers, in which the material moves in the direction of the polarized light upon irradiation, and phase changes back to solid when the irradiation stops. The underlying mechanisms of this phenomenon remain largely unknown. In this study, we discuss the general scenario related to the many facets of azobenzene-polymers, with a focus on the effects of photofluidic movement initiated by azobenzene photo-isomerization. Additionally, the recent advances and applications of the photofluidic movement of azobenzene-polymers in various fields such as photonics, micro/nano structuring, and surface engineering are highlighted.