A green route to silicananoparticles with tunable size and structure

A green and simple route to silica nanoparticles with tunable size, structure and stability is presented. Hybrid nanoparticles containing alginate, a polysaccharide, and silicates are obtained using the well-established spray drying technology. Subsequent exposure to water leads to the release of alginate and the particle structural re-organization viaOstwald ripening. Through adjustment of ripening time, of initial composition and concentration of bio-organic/inorganic precursors, silica nanoparticles with morphologies varying from plain spheres to hollow shells can be synthesized. The synthetic procedure is straightforward, inexpensive and environment-friendly, and may be suitable for large-scale production.