One‐pot synthesis of composite microspheres with core‐shell structure

Abstract

ABSTRACT One‐pot synthesis of thermoresponsive magnetic composite microspheres with a poly( N ‐isopropylacrylamide) (PNIPAM) shell and a Fe 3 O 4 core is demonstrated. Temperature sensitivity of PNIPAM was adopted to design the novel synthesis pathway. The as‐prepared composite microspheres have an obvious core‐shell structure with a mean size of approximately 250 nm. The Fe 3 O 4 core is approximately 5 nm and the thickness of the PNIPAM shell is approximately 10 nm. The content of Fe 3 O 4 in the composite microspheres can be controlled by this method. The composite microspheres experience a swelling and shrinking process in water by adjusting the temperature below and above the lower critical solution temperature (LCST) around 32 °C. These microspheres also show fine response to an external magnetic field. This work presents a platform to synthesize organic/inorganic composite microspheres in a facile and efficient approach. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2702–2708