CO2‐Activated Reversible Transition between Polymersomes and Micelles with AIE Fluorescence

Fluorescent polymersomes with both aggregation‐induced emission (AIE) and CO2‐responsive properties were developed from amphiphilic block copolymer PEG‐b‐P(DEAEMA‐co‐TPEMA) in which the hydrophobic block was a copolymer made of tetraphenylethene functionalized methacrylate (TPEMA) and 2‐(diethylamino)ethyl methacrylate (DEAEMA) with unspecified sequence arrangement. Four block copolymers with different DEAEMA/TPEMA and hydrophilic/hydrophobic ratios were synthesized, and bright AIE polymersomes were prepared by nanoprecipitation in THF/water and dioxane/water systems. Polymersomes of PEG45‐b‐P(DEAEMA36‐co‐TPEMA6) were chosen to study the CO2‐responsive property. Upon CO2 bubbling vesicles transformed to small spherical micelles, and upon Ar bubbling micelles returned to vesicles with the presence of a few intermediate morphologies. These polymersomes might have promising applications as sensors, nanoreactors, or controlled release systems. AIE polymersomes self‐assembled from CO2 responsive amphiphilic block copolymer PEG‐b‐P(DEAEMA‐co‐TPEMA) showed a reversible CO2‐driven vesicle–micelle transition. Vesicles transformed to small spherical micelles upon CO2 bubbling and micelles returned to vesicles upon subsequent Ar bubbling.