To better simulate the dynamic natural water environment, the aggregation of TiO2 nanoparticles was studied not by the widely applied static experimental method, but by a batch experiment conducted in a shaker.
Both ionic sodium dodecyl sulfate (SDS) and non-ionic nonylphenol ethoxylate (NPEO) surfactants can remarkably reduce the aggregation of nano-TiO2 and stabilize the aggregate when the surfactant concentration exceeds 0.015% (w:v).
The aggregation and sedimentation of nano-TiO2 are more remarkable in environmental aqueous matrices than in Milli-Q water, but surfactants are effective in reducing the aggregation and retarding the sedimentation of TiO2.