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Free keywords:
Coatings; Optical materials; Thin films; Sol–gel growth; Surface properties
Abstract:
A facile method of coating polystyrene (PS) particles with organo-silica and their functionalization was presented. By adding the organo-silane precursor into PS aqueous solution in presence of ammonia, an organo-silica shell could be coated on PS particles directly. This method has several characteristics. First, only one process, one precursor and one solvent were used. Second, the organic groups could be varied from methyl, propyl, vinyl, to mercaptopropyl. The third is the tunable shell thickness with a high monodispersity. The organo-silica shells are further functionalized. The PS@vinyl-SiO2
particles were used to assemble colloidal crystals, and further modified with bromine, resulting in tunable photonic band gaps. PS@mercaptopropyl-SiO2
particles allow the encapsulation of Au nanoparticles. The resulting 2.2 nm Au particles were stable at 550 °C and well-distributed in the whole SiO2
shell with a loading up to 20 wt%.
