TiO2在水及丙二醇介质中表面电性质的研究

0引言 固体颗粒在液相介质中的分散是基础研究领域和工业技术部门普遍遇到的问题 ?在化学工业领域,如涂料 ? 染料 ? 油墨 ? 化妆品等,固体颗粒的分散及分散稳定性直接影响着产品的质量和性能 ?TiO 2 颗粒的水基分散体系广泛应用于涂料 ? 油墨以及化妆品中,也是陶瓷制备过程中重

Study on Surface Charge Properties of Titanium Dioxide in Water and Propylene Glycol

Surface charge properties of titanium dioxide in water and propylene glycol have been discussed by proton-transfer phenomena.Electrophoresis shows significant differences between each type of titanium dioxide particles and between the two dispersion media.In aqueous solvent,the sign of the charge for titanium dioxide would change due to pH and surface chemical composition.However,in propylene glycol pH value could not result in the sign of the charge for uncoated titanium dioxide. Furthermore,the change due to pH and surface chemical composition. However, in propylene glycol pH value could not result in the sign of the charge for uncoated titanium dioxide. Furthermore, the effects of both alumina and silica coatings and media on the surface charge properties of titanium dioxide are due to proton-transfers. The acidity of hydroxyl groups on oxides surface is believed to be the direct reason that make them have different charge properties in solvents. It is favorable for the hydroxyl groups on the surface of particles to donate protons, as was observed by negative charge pertaining for dispersion in water at most values of pH. While in propylene glycol titanium dioxide particles are forced to accept protons, resulting in positively charged particles. Small amounts of water have a significant effect on the sign of the charge for uncoated titanium dioxide.