Switchable release and recovery of nanoparticles via a Pickering-emulsion-templated porous carrier

A Pickering-emulsion-templated macroporous polymer was utilized as a novel release carrier for switchable controlled release and recovery of nanoparticles. With silica nanoparticles as stabilizers, oil-in-water Pickering high internal phase emulsions were prepared as templates to synthesize porous poly(N-isopropylacrylamide) materials with silica nanoparticles inlaid in the polymer void walls. The porous materials can effectively avoid the diffusion of silica nanoparticles when the release is undesirable, and can resorb the released nanoparticles back from the aqueous solution simply by controlling the temperature. Because a wide range of functional nanoparticles can be used to stabilize Pickering emulsions, the method developed herein provides an alternative to prepare carriers for controlled release and recovery of functional nanoparticles.