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 phasetransition temperature (LCST) of 70 degrees 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 degrees 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.