논문 : 수환경 특성에 따른 은과 이산화티탄 나노입자의 응집 특성 연구

The aggregation behaviors of silver nanoparticles (AgNPs) and titanium dioxide (TiO2) nanoparticles were investigated. Time-resolved dynamic light scattering (DLS) was used to study the initial aggregation of AgNPs and TiO2 over a range of mono (NaCl) and divalent (CaCl2) electrolyte concentrations. The effects of pH, initial concentration of NPs and natural organic matters (NOM) on the aggregation of NPs were also investigated. The aggregation of both nanoparticles showed classical Derjaguin- Landau-Verwey-Overbeek (DLVO) type behavior. Divalent electrolyte was more efficient in destabilize the AgNPs and TiO2 than monovalent electrolyte. The effect of pH on the aggregation of AgNPs was not significant. But the aggregation rate of TiO2 was much higher with increasing pH. Higher NPs concentration leads to faster aggregation. Natural organic matter (NOM) was found to substantially hinder the aggregation of both AgNPs and TiO2. This study found that the aggregation behavior of AgNPs and TiO2 are closely associated with environmental factors such as ionic strength, pH, initial concentration of NPs and NOM.