Comparative study of sol-gel methods for the facile synthesis of tailored magnetic silica spheres

A direct, systematic and comparative study on the production of magnetic silica spheres (MSS) with control over their most relevant parameters, including size, morphology and magnetization, is presented. MSS were prepared by a simple and efficient sol-gel method varying different synthesis parameters. Porous and non-porous MSS with sizes from similar to 110 to 500 nm, saturation magnetization between 23 and 3 emu g(-1) and stable over a large pH range can be thus obtained in a facile procedure, allowing to tailor particle properties for specific applications.