Hydrophilic dual-responsive magnetite/PMAA core/shell microspheres with high magnetic susceptibility and ph sensitivity via distillation-precipitation polymerization
Article first published online: 27 APR 2011
Copyright © 2011 Wiley Periodicals, Inc.
Journal of Polymer Science Part A: Polymer Chemistry
Volume 49, Issue 12, pages 2725–2733, 15 June 2011
How to Cite
Ma, W., Xu, S., Li, J., Guo, J., Lin, Y. and Wang, C. (2011), Hydrophilic dual-responsive magnetite/PMAA core/shell microspheres with high magnetic susceptibility and ph sensitivity via distillation-precipitation polymerization. J. Polym. Sci. A Polym. Chem., 49: 2725–2733. doi: 10.1002/pola.24705
- Issue published online: 6 MAY 2011
- Article first published online: 27 APR 2011
- Manuscript Accepted: 3 APR 2011
- Manuscript Received: 5 MAR 2011
- core-shell polymers;
- particle size distribution;
- radical polymerization
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.