Dispersibility and Hydrophobicity Analysis of Titanium Dioxide Nanoparticles Grafted with Silane Coupling Agent

The high surface energy of TiO2 nanoparticulate leads to the aggregation of nanoparticles. The grafted modification of nanoparticles is necessary in order to improve its dispersibility in the organic solvent. The effect of grafted modification with silane coupling agent on dispersibility and lipophilicity of TiO2 nanoparticles was investigated. The factors of the modification were discussed, such as the amount of silane coupling agent, pH value, and reaction time. The average sizes of the TiO2 nanoparticles were 200-300 nm. The thermogravimetric analysis (TGA) curves indicated that the TiO2 nanoparticle surface had been grafted with the silane coupling agent. The zeta potential showed that modified TiO2 could disperse well in the organic solvent. The lipophilic degree and contact angle suggested that the modified TiO2 had low surface energy and changed from a hydrophilic nature to a lipophilic nature.