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

Fluorescent polymersomes with both aggregation‐induced emission (AIE) and CO 2 ‐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 PEG 45 ‐ b ‐P(DEAEMA 36 ‐ co ‐TPEMA 6 ) were chosen to study the CO 2 ‐responsive property. Upon CO 2 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.