Synthesis, characterization and antibacterial action of hollow titania spheres

Hollow titania spheres were synthesized using the cationic polystyrene lattices which were prepared by polymerization in suspension of styrene using 2,2'-azobis (2-methylpropionamidine) dihydrochloricle (AMPA) as an initiator. These cationic colloidal particles were dispersed in absolute ethanol in the presence of poly(vinylpyrrolidone) (PVP), solution of sodium chloride (NaCl) and mixed with ethanolic solutions of titanium tetraisopropoxide (TTIP). Subsequently, hollow spheres of titania compounds were obtained by calcinations of the so-coated polystyrene lattices at elevated temperature in air. The hollow titania spheres were characterized with scanning electron microscopy (SEM), FT-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Moreover, antibacterial action of illuminated hollow titania spheres on pure culture of Escherichia coli (E. coli) was studied. A decrease of E. coli concentration was observed after illumination of bacteria in the presence of hollow titania spheres. (c) 2007 Elsevier Ltd. All rights reserved.