A new strategy to prepare thermo-responsive multicompartment nanoparticles constructed with two diblock copolymers

Multicompartment block copolymer nanoparticles (MCBNs) constructed with two diblock copolymers of poly[N-(4-vinylbenzyl)-N,N-diethylamine)]-b-polystyrene (PVEA-b-PS) and poly[2-(dimethylamino) ethyl methacrylate]-b-polystyrene (PDMAEMA-b-PS) were prepared through the two macro-RAFT agents co-mediated dispersion polymerization. These MCBNs dispersed in water contain a 33 nm solvophobic core of the PS block, 5 nm discrete nodules of the PVEA block and a solvophilic corona of the PDMAEMA block. These MCBNs are thermo-responsive both in water and in methanol. In water, the corona-forming PDMAEMA block exhibits the soluble-to-insoluble phase transition at a temperature above the phase-transition temperature (LCST) of 70 °C to deposit on the PS core of MCBNs. In methanol, the PVEA nodules on the PS core are dissolved at a temperature below LCST of the PVEA block at 53 °C, and when the temperature increases above LCST the PVEA block reversibly deposits on the PS core to form discrete PVEA nodules on the PS core. The prepared MCBNs showing thermo-response both in water and in methanol are believed to be useful in nanotechnology.