A NOVEL SYNTHESIS ROUTE TO BIO-FUNCTIONALIZED AND MAGNETICALLY ADDRESSABLE FERROGELS

摘要

In this paper, ferrogels comprising nanocrystalline Fe3O4 and γ-FeOOH dispersed in polyvinyl alcohol gel matrix were synthesized via a novel route, without using any crosslinking agent. A moderately high-pressure environment instead was used for the synthesis. The ferrogels were found to be stable over a long period of time and were characterized by transmission electron microscopy (TEM), M?ssbauer spectroscopy and DC magnetization studies. TEM studies showed that the particles are mostly spherical with an average size of 10 nm. M?ssbauer spectra of the as prepared gels at different temperatures showed the presence of superparamagnetic particles in them. The gels were found to be magnetically ordered at 20 K giving characteristic six-finger M?ssbauer patterns. Bulk magnetic properties of the gels were studied by DC magnetization measurements.