Encapsulation of Silver Nanoparticles into Polystyrene Microspheres

Hydrogen reduction of a saturated silver(I) oxide solution at elevated temperatures in the presence of ∼200 nm polystyrene (PS) microspheres followed by acetone treatment lead to the encapsulation of the resulting silver nanoparticles (Ag NPs) into the PS microspheres. Extinction spectra reveal an expected red-shift of the characteristic plasmon resonance frequency of Ag−PS core−shell particles due to the increase in the surrounding dielectric constant. The Ag−PS core−shell particles maintain their stability when redispersed back into water.