Featuring unique electronic,optical,thermal and photoactive properties,nano-TiO2are ideal candidates for a multitude of current and potentialindustrial applications.With the rising demand for nano-TiO2and anincrease in their production, nano-TiO2release into the environment isinevitable.Once present in the biosphere, the novel nano-TiO2may effectshuman and environmental health as a result of exposure via differentroutes.So it is essential to study environmental behavior of TiO2nanoparticles in aquatic environments.This study is in the basis of the theoretical basis, using the extendedDLVO theory model to predict the water environment of the nanometerTiO2,and analysising the main factors on nanometer TiO2dispersion andsedimentation in water. The results show that the electrolyte concentrationand ion valence, water temperature, pH and the Hamaker constant factorswill impact on the dispersion properties of nano-TiO2.The dispersion and deposition of the aqueous suspensions ofnano-TiO2nanoparticles were studied in the presence of surfactant and pH value,and were explained in DLVO theory.The results showed that nano-TiO2exists in the form of aggregates in the water.The size of the aggregatesdue to factors outside influence.Strong acid or alkali conditions,thedispersion properties of nano-TiO2was relatively good.Near the isoelectricpoint(pH=6.3), the worst of the dispersion properties of nano-TiO2particle size.It shows that Tween80ã€Sodium dodecyl benzene sulfonateand Hexadecyltrimethylammonium chloride enhanced the dispersionbehavior of nano-TiO2nanoparticles in aqueous solutions. The mechanismof the Hexadecyltrimethylammonium chloride and Sodium dodecyl benzene sulfonate dispersing nano-TiO2nanoparticles is changing the zetapotential of nano-TiO2nanoparticles surface, consequently enhancing therepulsive force of nano-TiO2nanoparticles, stabilitating the he aqueoussuspensions, decreasing the deposition of nano-TiO2nanoparticles in theaqueous suspensions; The mechanism of the Twain80scattering nanometernano-TiO2is twain80can significantly reduce the surface tension of thewater, so the stabilization of space is relatively obvious. |