Polymer Surface Modification On The Structure And Properties Of Titanium Dioxide

The study on preparation and property of nanocrystalline titanium dioxide are very important parts of nanomaterial research. In this paper, a series of poly(acrylic acid)/ titania ( PAA/TiO2) and poly(acryl amide) / titania (PAM/TiO2) catalysts have been synthesized by hydrothermal method, using tetrabutyl titanate(TBT) as material, polyacrylic acid (PAA) and polyacry lamide (PAM) as modifying agents. The catalysts were characterized in detail via XRD, TEM, BET, FT-IR, SPS and TG technologies. The effects of acidity and the content of polymer on structure of TiO2, and the growth mechanism of TiO2 nanocrystalline in different condition were investigation. The photocatalytic activity of polymer-modefied TiO2 was studied by degrading the Rhodamine B (RhB), active-brilliant red (X3B) and phenol solution. Meanwhile, process parameters, which could affect the photocatalytic activity of the products, such as acidity, the content of polymer, hydrothermal temperature and hydrothermal time were discussed.The experimental results suggested that the presence of PAA could change the crystalline phase of TiO2 from rutile to anatase, even if in high acid concentration. The proposed mechanism involving hydrogen bond is discussed to explain the variation of the crystalline phase. The IR result indicated that the essence of PAM-modified TiO2 could be hydrogen bond worked between hydroxyl group on the TiO2 surface and amide group in the PAM. We have successed to prepare the PAA/TiO2 and PAM/TiO2, which have higher specific surface area, more homogeneous and smaller particles than pure TiO2. The SPS results indicate that the functional group of polymers could act as the capture trap of the photoinduced carriers, and the recombination of the photoinduced electrons and holes was inhibited effectively in the photocatalytic process. It is favor to improve the photocatalytic activity for samples. The catalysts containing 6.0% PAA/ TiO2 and 6.7% PAM/ TiO2 (wt %) showed the highest photocatalytic activity respectively.