Abstrait

Preparation of carboxylated temperature-responsive magnetic nano composite polymer particles

M.A.Alam, T.Sultana, M.A.Rahman, M.A.Nuri, M.A.J.Miah, H.Ahmad

Magnetic (Fe3O4) nano particles are very promising materials for many biomedical applications because of their ability to be manipulated and detected with an external magnetic field. In the present investigation a systematic approach has been proposed to prepare temperature-sensitive magnetic nano composite polymer particles. Nano-sized Fe3O4 particles were first prepared by co-precipitation of Fe2+(aq) and Fe3+(aq) in presence of aqueous NaOH solution. Fe3O4 nano particles were then functionalized with a silane coupling agent followed by two step polymerization. In the first step radical copolymerization of styrene and N-isopropyl acrylamide (NIPAM) was carried out in presence of functionalized Fe3O4 as seed particles. The produced latex particles were named as Fe3O4/P(S-NIPAM). Then seeded copolymerization of NIPAM, methacrylic acid (MAA) and N,NÂ’-methylene-bis-acrylamide (MBAAm) was carried out in presence of Fe3O4/P(S-NIPAM) composite seed particles. The final composite polymer particles named as Fe3O4/P(S-NIPAM)/P(NIPAM-MAA-MBAAm) were characterized by electron micrographs, FTIR, and thermogravimetric analyses. The magnetic nano composite polymer particles containing carboxyl groups exhibited temperature-sensitive phase transition at temperature close to 30°C.