Integrating the Concept of Biomimetics into Teaching Experiments: Preparation and Evaluation of an Azo Molecule-Based Polymer Film

A comprehensive teaching experiment plan tailored forthird-yearundergraduates has been developed. Initially, instructors synthesize(E)-2-(4-((4-(2-hydroxyethoxy)-3-methylphenyl)­diazenyl)­phenoxy)-ethan-1-ol­(M-Azo-2)monomer as part of the preclass preparation. Subsequently, studentsperform an acylation reaction experiment to prepare an azobenzenederivative containing cross-linking points on both sides. This derivativeis then combined with poly­(ethylene glycol) dimethacrylate in theabsence of external solvent under conditions conducive to radicalpolymerization, resulting in a thin film that exhibits light-wet dual-stimulationresponsiveness. This process enables students to comprehend both thechemical reactivity and photoisomerization propensity of azobenzeneto effectively bridge elements of organic chemistry and polymer chemistry.The experiment demonstrates three vivid and novel biomimetic phenomena:"color-changing flowers", "phototropic seedlings",and "mimosa", which display photochromic, light-induceddeformation, and humidity-responsive behavior of the film, respectively.This experiment enhances students' appreciation for the applicationpotential of biomimetic materials and fosters innovative scientificthinking.