| Hyper-dispersant C is the best modifier by selecting from many kinds of different modifiers. After nano-TiO2 is modified by hyper-dispersant C, non-polar decorate surface of TiO2 through adsorb hyper-dispersant molecule to surface of TiO2, so surface of TiO2 changed from polarity and hydrophilic to non-polar and hydrophobic. The result shows that the modified TiO2 can steady suspend more than 960h in non-polarity solvent, the TEM shows the modified TiO2 particles are nanometer and whose average size is almost less than lOOnm. Wetting test and the FT-IR show TiO2 particles have been changed from hydrophilic to hydrophobic, and vibration peaks for - CH2- and C=O-O appear in infrared spectrum of modified TiO2, which show surface states of TiO2 have been changed, and TiO2 can excellent consist with non-polar material. The experiment foundthat the best dosage of hyper-dispersant C is 6%, the best modified time is lh, the best modified temperature is 75 ℃ and the best disperse solvent is Jia.Nano-TiO2 is modified by in-situ polymerization, and at the same time nano-TiO2/silicon-acrylic composite emulsion is prepared. The result of TEM shows that nano-TiO2 particles in silicon-acrylic emulsion were better dispersed and its measure is nanometric. The spectrophotometric determination showed that nano-TiO2/silicon-acrylic composite emulsion, whose ultraviolet absorption is over 2.0 in 200~400nm, and whose light absorption is obvious in visible region. Sterilization test showed: the killing rate of Bacillus subtilis var. niger, Staphylococcus aureus and Escherichia coli are over 98%, and hepatitis B antigen (HbsAg) can be changed from positive to negative after 8h. So we can conclude that nano-TiO2/silicon-acrylic composite emulsion film has obvious photocatalysis and transforms energy of light into chemical energy with antibacterial and antivirotic.
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