Smart block copolymers of PVP and an alkylated PVP derivative: synthesis, characterization, thermoresponsive behaviour and self-assembly

Stimuli responsive block copolymers of biocompatible poly(3-ethyl-N-vinylpyrrolidone) and poly(N-vinylpyrrolidone), i.e. EPVP–PVP, were readily synthesized via RAFT-mediated polymerization. The thermoresponsive behaviour and temperature induced self-assembly, in aqueous solutions, was studied using various spectroscopic and microscopy techniques. We obtained different morphologies, i.e. spherical and cylindrical micelles, and vesicles, via temperature induced self-assembly, of aqueous solutions of a single diblock copolymer by simply adjusting the solution concentration. This study establishes the biocompatible EPVP/PVP combination as a versatile stimuli responsive block copolymer system suitable for applications in drug delivery.