Facile preparation of ferromagnetic alginate-g-poly(vinyl alcohol) microparticles

Alginate-g-poly(vinyl alcohol) was physically cross-linked with Fe(II) ion in a surfactant-free emulsion system to form microparticles via in situ precipitation. The microparticles were subjected to oxidation in aqueous of pH 13 at ambient temperature and transformed into magnetic ones within minutes. X-ray diffractometry showed that magnetic Fe3O4 was formed and it was further confirmed with a vibrating sample magnetometer measurement. Scanning electron microscopy examinations indicated that the iron oxide was well embedded into ferrous alginate and the size of particles was around 0.2–1.2 μm.