The In-Suit Emulsion Polymerization Of Nano-TiO₂ And Self-Separation Coating

In this paper, the self-separation coating with photocatalytic catalyzingactivity based on acrylate latex made from acrylates and acrylate containingfluorine was prepared. The main investigation and results were as follows.The first is the synthesis of acrylate latex containing fluorine. A kind ofacrylate copolymer emulsion containing fluorine is prepared, withdodecafluoroheptyl methacylate, butyl acrylate, methyl methylacrylate, acrylicacid as basic monomers. The experiments data indicate that the compositeemulsifiter of polassium perfluoroctane sulfonate, MS-1,SEN-10,NP-40 is thebest and it's best amout is 4．2wt%. The compositions of the latex fims werecharacterized by FTIR, the result showed that the existence of reaction.The second is relative to the preparation and modification of nanoscaletitanium dioxide hydrosol. Using TiCl₄ to hydrolyze, adding the ammoniasolution to adjust pH, then adding hydrogen peroxide to dissolve titaniumhydroxide, heating for the long time at low temperature to cause crysatal-typeconversion, nano-level mixed phase titanium dioxide hydrosol is gained. Theresult of UV-visible spectroscopy show that the absorption band of thetitanium dioxide hydrosol is extend to visible light region, what'more theabsorption band in ultraviolet region is strong and wide. The photocatalytic activity of titanium dioxide sol solution is evaluated by the photocatalyticoxidation of formaldehyde and antibacterial, the result proved to be that thetitle nanoscal titanium dioxide had excellent photo-catalyzing activityexpoured to visible-light. HEMA was used as surface modifier ofnano-titanium dioxide sol solution. The steady chemical bonds formedbetween hydroxyl groups of HEMA and hydroxyl groups of nano-titaniumdioxide surface was characterized by FTIR Spectrum.The third is intrducing the above nano-titanium dioxide sol solution intofluoropolymer emulsions by in-suit emulsion polymerization. Blended latexwas prepared by mixing fluoropolymer emulsions with acrylate emulsions,self-separation will happen during the film-formation of the latex blends. Inthis gradient material, one surface side of the blend film exhibits specialsurface properties, such as antifouling property, self-cleaning property,water-resisitancec, oil-resistance and photocatalytic activity, the other surfaceside shows good adhesion to matrixes. The surface analysis from XPSindicated that the fluorinated component preferentially self-separation at thefilm-air interface. The photocatalytic activity of blended emulsion is evaluatedby the photocatalytic oxidation of formaldehyde, the result proved that thegood photocatalytic activity of sample.