Photoresponsive supramolecular soft materials in aqueous media

Abstract

Nature has provided the most elegant examples of self-assembled systems derived from amphiphiles. Natural phospholipids self-assemble into biological membranes in living organisms, which demonstrate automatic smart response in the presence of functional proteins. Inspired by nature, supramolecular self-assembly of photoresponsive molecular amphiphiles in aqueous media, an emerging area of materials science, is a promising synthetic strategy towards creating biomimetic functions. It is a bottom-up approach towards the development of smart soft materials with well-defined structures, ranging from one-dimensional nanostructures to isotropic entangled three-dimensional networks and anisotropic three-dimensional structures. In this thesis, we focus on designing self-assembled soft materials consisting of azobenzene-based or molecular-motor-based amphiphiles in aqueous media, allowing for energy conversion and amplification from molecular motions to macroscopic delicate functions. In addition to identifying the key processes for the amplification from nanoscale motions into macroscopic response, the smart soft materials also show interesting applications in a wide range of areas. The smart soft materials are employed in industrial processes to solve practical problems, e.g., minimizing pollutants discharge in textile coloring process, as well as in biological systems to creating biomimetic materials, e.g., muscle-like strings which exhibit photoactuation. In this thesis, we focus on structures and functions of photoresponsive molecular amphiphiles and aim at proving insight into the fascinating supramolecular self-assembly of photoresponsive amphiphiles in aqueous media.