Aggregation kinetics of nanosilver in different water conditions

Shao-Feng Chen and Hongyin Zhang

Abstract

In this study the effect of different water conditions on the aggregation kinetics of nanosilver (nAg) is evaluated. The obtained results show that the aggregation rate of nAg increases with increasing electrolyte concentration. Divalent cation (Ca²⁺) can more effectively induce aggregation than monovalent cation (Na⁺). Critical coagulation concentration of nAg in NaCl solution is about 40 times higher than that in CaCl₂ solution. This study also indicates that aggregation rate of nAg in water condition containing high Ca²⁺ concentration in presence of humic acid is higher than that without humic acid due to the bridging effect of humic acid–Ca²⁺ complex. Finally, aggregation rate of nAg in seawater is higher than that in lake water