Promoting the Photoresponse Rate with Micelles in Hydrogels

Abstract Fluorescent hydrogels have immense potential and are widely studied for on demand displays. Response rate of fluorophores upon stimuli within the hydrogel matrix is a key role to improve the timely responsiveness, but rare reports are elaborated on it. In this work, the photoisomeric spiropyran methacrylate (SPMA) is introduced into the poly (2‐hydroxyethyl methacrylate) hydrogel to fabricate a stimuli‐responsive fluorescent hydrogel. Interestingly, the photoresponse rate of SPMA in the hydrogel is greatly accelerated at the presence of F127 micelles than without it. Both of the absorbance and fluorescence intensity of the hydrogels at the photostationary state are improved obviously with micelles. Besides, the normalized absorbance and the fluorescence kinetic studies indicated a more than 2 times quicker isomerization process. The absolute fluorescence quantum yields of SPMA in the hydrogel is also increased. These can be attributed to the hydrophobic microenvironment provided by the F127 micelles that facilitated the conformation transition of SPMA. Thus, the synergetic effect of the increased amount of activable SPMA and the promoted speed of isomerization contributed to the accelerated photoresponse of the prepared hydrogel. Taking advantage of these virtues, a timely and multi‐responsive on‐demand information encryption system is realized.