Hydrophilic dual‐responsive magnetite/PMAA core/shell microspheres with high magnetic susceptibility and ph sensitivity via distillation‐precipitation polymerization |
| |
Authors: | Wanfu Ma Shuai Xu Jumei Li Jia Guo Yao Lin Changchun Wang |
| |
Affiliation: | 1. Key Laboratory of Molecular Engineering of Polymers, Ministry of Education, and Department of Macromolecular Science, Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China;2. Polymer Program, Institute of Materials Science & Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269 |
| |
Abstract: | A facile and effective approach to preparation of dual‐responsive magnetic core/shell composite microspheres is reported. The magnetite(Fe3O4)/poly(methacrylic acid) (PMAA) composite microspheres were synthesized through encapsulating γ‐methacryloxypropyltrimethoxysilane (MPS)‐modified magnetite colloid nanocrystal clusters (MCNCs) with crosslinked PMAA shell. First, the 200‐nm‐sized MCNCs were fabricated through solvothermal reaction, and then the MCNCs were modified with MPS to form active vinyl groups on the surface of MCNCs, and finally, a pH‐responsive shell of PMAA was coated onto the surface of MCNCs by distillation‐precipitation polymerization. The transmission electron microscopy (TEM) and vibrating sample magnetometer characterization showed that the obtained composite microspheres had well‐defined core/shell structure and high saturation magnetization value (35 emu/g). The experimental results indicated that the thickness and degree of crosslinking of PMAA shell could be well‐controlled. The pH‐induced change in size exhibited by the core/shell microspheres reflected the PMAA shell contained large amount of carboxyl groups. The carboxyl groups and high saturation magnetization make these microspheres have a great potential in biomolecule separation and drug carriers. Moreover, we also demonstrated that other magnetic polymeric microspheres, such as Fe3O4/PAA, Fe3O4/PAM, and Fe3O4/PNIPAM, could be synthesized by this approach. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011. |
| |
Keywords: | colloids core‐shell polymers nanocomposites particle size distribution radical polymerization |
|
|