(267h) Azobenzene Switches Assemblies of Pnipam in an Ionic Liquid with Their Multi-Functions

Photocontrolled self-assmebly of thermoresponsive polymers have been well studied in ionic liquids (ILs), featured by its precise control in a contactless manner whereas light can switch self-assembly of thermoresponsive polymers. The general method is to incorporate azobenzene moieties into polymer chains or end of the polymers^[1]. However, there is a noticeable problem that azobenzene aggregation occurred together with polymer associations will have a negative influence on response speed. Also, azobenzene moieties connected with thermoresponsive polymers makes it hard to define the mechanism difference of light or thermo- triggered self-assembly. Thus, we proposed a novel method in using of azobenzene-based molecular triggers to tune thermoresponse in ILs where azobenzene moieties are structurally separated from thermoresponsive polymers, beneficial to clarify the mechanisms.Thus, structural independence between thermo- and photo- componenets were proposed here in using azobenzene molecule and poly(N-isopropyl acrylamide) (PNIPAm). As a result, photoresponsive assemblies including phase transitions, micellizations and gelations of the PNIPAm in ILs have been achieved as well as photomodulated ion conductivity, wettability and adhesive force. Those original researches would enrich our knowledge of stimuli self-assembly in ILs and provide a novel platform to build various stimuli smart systems.