Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan, Republic of China.
Environ Toxicol Chem. 2012 Aug;31(8):1693-8. doi: 10.1002/etc.1898. Epub 2012 Jul 3.
The present study aims to evaluate the effect of inorganic ions on the aggregation kinetics of stabilized titanium dioxide (TiO(2) ) nanoparticle (NP) suspension, an NP mode widely used in consumer goods and in aquatic environments. The point of zero charge of stabilized TiO(2) NPs was approximately pH 6.5. The particle size of the stabilized TiO(2) NP suspensions increased with the increase in salt concentrations. The additional salts caused the shift of zeta potentials of TiO(2) suspensions to a lower value. The TiO(2) NPs aggregated more obviously in the presence of anions than cations, and the effect of divalent anions was larger than that of monovalent anions. The critical coagulation concentration (CCC) values for commercial TiO(2) NP suspensions with positive surfaces were estimated as 290 and 2.3 meq/L for Cl(-) and SO 42-, respectively. These CCC values of stabilized TiO(2) NP suspensions are higher than those of TiO(2) NP powders, indicating greater stability of the commercial stabilized TiO(2) NP suspensions. The effects of commercial TiO(2) NP suspensions still need to be explored and defined. Derjaguin-Landau-Verwey-Overbeek (DLVO) analysis can explain the aggregation behaviors of stabilized TiO(2) NP suspensions. Such an understanding can facilitate the prediction of NP fate in the environment.
本研究旨在评估无机离子对稳定二氧化钛（TiO2）纳米颗粒（NP）悬浮液聚集动力学的影响，这种 NP 模式广泛应用于消费品和水生环境中。稳定 TiO2 NP 的零电荷点约为 pH 6.5。稳定 TiO2 NP 悬浮液的粒径随盐浓度的增加而增加。额外的盐会导致 TiO2 悬浮液的动电位向更低的值移动。与阳离子相比，阴离子更能使 TiO2 NP 明显聚集，而二价阴离子的效果大于单价阴离子。具有正表面的商业 TiO2 NP 悬浮液的临界聚沉浓度（CCC）值分别估计为 290 和 2.3 meq/L 的 Cl-和 SO42-。这些稳定 TiO2 NP 悬浮液的 CCC 值高于 TiO2 NP 粉末，表明商业稳定 TiO2 NP 悬浮液具有更高的稳定性。商业 TiO2 NP 悬浮液的影响仍需要进一步探索和定义。Derjaguin-Landau-Verwey-Overbeek（DLVO）分析可以解释稳定 TiO2 NP 悬浮液的聚集行为。这种理解可以促进对 NP 在环境中命运的预测。
