Well-defined spherical titania-octadecylamine (titania-ODA) (titania: titanium dioxide) hybrid particles containing silane-coupling reagents including aminopropyl, sulfanylpropyl, octadecyl, and phenyl groups (molar Ti:silane-coupling reagent ratio of 50:1) were prepared by sol-gel reaction of titanium tetraisopropoxide with the aid of a flow reactor. Average particle sizes were 520, 380, 540, and 510 nm for aminopropyl, sulfanylpropyl, octadecyl, and phenyl group containing particles, respectively. ODA was removed by washing the as-synthesized products with acidic EtOH, resulting in the formation of organosilyl group containing nanoporous titania. The porosity was investigated by the nitrogen adsorption/desorption isotherms (BET surface area of 250 to 400 m 2g -1) and the surface hydrophilicity/hydrophobicity is discussed based on the water and benzene vapor adsorption/desorption isotherms. Crystallization of anatase within the spherical particles is possible by postsynthetic hot water or hydrothermal treatment.
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