Thiol-functionalized silica colloids, grains, and membranes for irreversible adsorption of metal(oxide) nanoparticles

Thiol-functionalization is described for silica surfaces from diverging origin, including commercial silica nanoparticles and Stِber silica as well as silica structures provided by porous glasses and novel polymer-templated silica membranes. The functionalization allows in all cases for the irreversible binding of metal(oxide) particles from a solution. Examples are the adsorption of CoFe2 O4 particles for the preparation of magnetizable silica colloids and silica structures, and gold nanoparticles that directly nucleate and grow on thiol-functionalized silica in a solution of HAuCl4 upon addition of a reducing agent.