Heteroaggregation of CeO 2 and TiO 2 engineered nanoparticles in the aqueous phase: Application of turbiscan stability index and fluorescence excitation-emission matrix (EEM) spectra

摘要

Graphical abstractThe utilization of TSI and Fluorescence EEM spectra can overcome the limitation of traditional methods and tools for heteroaggregation.Display OmittedAbstractCeO2and TiO2engineered nanoparticles (ENPs) are being increasingly used in many applications. Due to their properties, heteroaggregation between these two types of ENPs is very likely, which can determine their fate and transport. However, the heteroaggregation behavior of CeO2and TiO2ENPs is still not clear, partly due to the lack of appropriate tools. In this study, we investigated the application of Turbiscan Stability Index (TSI) for the measurements of CeO2/TiO2ENP heteroaggregation. TSI was found to be effective to investigate the heteroaggregation and stability of the CeO2-TiO2ENPs system. Increasing CeO2/TiO2ENPs ratio reduces the TSI values, indicating higher stability. Fluorescence excitation-emission matrix (EEM) spectra were used to study the interface interaction between humic acid (HA) and CeO2/TiO2ENPs. The TSI value of ENPs were rising with the increasing of CeO2/TiO2ENPs ratios in the H River or Q Reservoir water. In addition, their variation trends were similar to those in well-controlled synthetic water. Proposed interaction mechanisms include surface charge attraction and competitive adsorption.]]>