Characterization of surface properties of titanium dioxide by inverse gas chromatography
The surface energy and acid/base constants of three kinds of titanium dioxide(TiO2)were measured by inverse gas chromatography(IGC)to investigate the effect of organic treatment on the sur-face properties of TiO2.The non-polar surface energy of the samples were calculated by using different molecular probes at different temperatures.The results indicate that non-polar surface energy γds of TiO2 decreases with the increase of organic cladding amount at the same temperature(within the testing tem-perature range).As the temperature increases,γds of TiO2 decreases.Meanwhile,the acid-base compon-ent of surface energy was studied by using polar molecules as probe molecules,revealing that the sur-face of titanium dioxide is amphoacid.Since the surface of TiO2 presents acidic,the reaction between organic agents and the hydroxyl groups on the surface of TiO2 leads to the decrease in the surface acid sites and thus the surface acidity of TiO2.However,when excessive organic agent is added,some hy-droxyl groups generated by organic agents hydrolyzation would not react with TiO2,resulting in the in-crement of TiO2 surface acidity.
TiO2surface propertiesinverse gas chromatography(IGC)organic agents
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