A Highly Fluorescent and Photoresponsive Polymer Gel Consisting of Poly(acrylic acid) and Supramolecular Cyanostilbene Crosslinkers

摘要

A poly(acrylic acid)-based polymer gel exhibiting strong fluorescence and high photoresponsibility is prepared by using a cyanostilbene derivative as a self-assembling supramolecular crosslinking agent, which generates conceptually new multiple hydrogen bonds in the gel system. This polymer gel in ethanol shows the gel-to-sol transition upon UV light irradiation with concomitant fluorescence color and intensity changes, which are attributed to the trans-to-cis photoisomerization of the supramolecular crosslinkers. Aggregation-induced enhanced emission (AIEE) behavior of the trans-cyanostilbene derivative enables a highly fluorescent polymer gel (phi(F) = 0.68) with green color (lambda(em) = 541 nm), which can be switched into a blue fluorescent sol (lambda(em) = 506 nm and phi(F) = 0.12) upon UV irradiation.