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

A comprehensive teaching experiment plan tailored for third-year undergraduates 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, students perform an acylation reaction experiment to prepare an azobenzene derivative containing cross-linking points on both sides. This derivative is then combined with poly(ethylene glycol) dimethacrylate in the absence of external solvent under conditions conducive to radical polymerization, resulting in a thin film that exhibits light-wet dual-stimulation responsiveness. This process enables students to comprehend both the chemical reactivity and photoisomerization propensity of azobenzene to 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-induced deformation, and humidity-responsive behavior of the film, respectively. This experiment enhances students’ appreciation for the application potential of biomimetic materials and fosters innovative scientific thinking.