Titania coated silica spheres (SiO2@TiO2) prepared by heterocoagulation of silica and titania nano-particles were investigated as catalyst in he photodegradation of rhodamine B (RB) in aqueous solution. The silica spheres were prepared by the well-known Stöber method and titania ol by a hydrolysis–condensation reaction in acidic media. The uncoated and coated particles were characterized by zet...

Copper oxide nanoparticles within hollow mesoporous silica spheres were prepared by binding/adsorbing Cu2+ or [Cu(NH3)4(H2O)2]2+ ions on the surface of carbon spheres, followed by formation of a mesoporous silica shell by sol-gel processing and calcination in air. The CuO nanoparticles can subsequently be converted into Cu3N nanoparticles by nitridation with ammonia. The effect of the different...

Mesoporous silica materials with a variety of morphologies, such as monodisperse microspheres, gigantic hollow structures comprising a thin shell with a hole, and gigantic hollow structures consisting of an outer thin shell and an inner layer composed of many small spheres, have been readily synthesized in mixed water-ethanol solvents at room temperature using cetyltrimethylammonium bromide (CT...

Nanoscale Ga particles down to 5 nm were fabricated by an explosion via an in situ electron-beam irradiation on microscale silica-covered Ga balls in a transmission electron microscope. The explosion is confirmed to be a Coulomb explosion because it occurs on the surface rather than in the whole body of the insulating silica-covered Ga micro-balls, and on the pure Ga nano-balls on the edge of c...

Colloidal silica bonded refractory castables have been developed recently. It was found that colloidal silica is one of the best binders can substitute other binders such as cement in No Cement Castable (NCC) and Ultra Low Cement Castable (ULCC) refractories. Also composition of colloidal silica with appropriate additives resulted in a gel form which makes the initial strength. Moreover, the na...

porous hollow glass microspheres have many uses, including encapsulation of active materials. in this paper a fast and facile method for fabricating porous hollow glass-microspheres was demonstrated by etching them using dilute hydrofluoric acid. then, a highly reactive amine was infiltrated into the etched glass microspheres. scanning electron microscopy was conducted for the hollow glass micr...