Tetraphenylethylene-appended poly(ethylene-alt-maleic anhydride) derivatives: functional group-dependent stimuli-responsive fluorescence

Stimuli-responsive aggregation-induced emission (AIE) active polymers hold great promise for a wide range of future applications. In the present work, an efficient post-polymerization modification approach was developed to synthesize AIE-active polymers with commercial poly(ethylene-alt-maleic anhydride) (PEM) as the parent polymer and 2-(4-(1,2,2-triphenylvinyl)phenoxy)ethan-1-amine as a model modification reagent. By performing hydrolysis, amidation, or esterification reactions on the maleic anhydride groups, we obtained four types of tetraphenylethylene-appended PEM derivatives successfully. The PEM derivatives displayed wide range-tunable pH-responsive emission characteristics as well as CO2- and H2O2-responsive photoluminescence depending on the functional side groups introduced. These intriguing results highlight the effectiveness and importance of post-polymerization modification in obtaining highly customizable structures and ‘signaling’ performance in stimuli-responsive AIE-active polymers.