PS@poly(NIPAM-co-AA) core@shell nanoparticles: size control and tuning of LCST

Abstract

Here, we demonstrate a synthetic approach to precise size control of PNIPAM-based core@shell nanoparticles prepared by microemulsion polymerization as well as control of low critical solution temperature (LCST) of their water dispersions. The size of the PS-core can be tuned to ∼30 nm by a simple increase of mechanical stirring up to 1200 rpm, while the thickness of the thermoresponsive @poly(N-isopropyl acrylamide-co-acrylamide) shell can be controlled by varying the polymerization time. The effect of not only a molar ratio or co-monomer nature but also a strong influence of a thermoresponsive shell thickness on the LCST was found.