为了优化用于环境风险模拟研究的纳米二氧化钛颗粒溶胶的制备方法,研究了超声时间、分散剂、静置时间对商购纳米二氧化钛分散效果的影响,从而确定出分散体系稳定、粒径小且二氧化钛浓度较高的纳米溶液,以促进工程纳米材料环境风险的研究。结果表明,在100 mL超纯水中先加入六偏磷酸钠(SHMP)500 mg作分散剂,再加入100 mg商购纳米二氧化钛,然后超声15 min,并静置6 d,最终可得到平均粒径为(196±20)nm,TEM表征粒径为50~80 nm,Zeta电位为(-51.3±6.7)mV,实测分散质量浓度为(61.89±5.41)mg/L的颗粒溶胶。该方法可获得较高浓度、稳定的纳米二氧化钛颗粒溶胶,可为工程纳米材料环境风险模拟研究奠定良好的基础。
Objective of this study was to develop a practical method to prepare nano-size Ti02 sol for improving environmentalrisk studies of engineering nano materials. Thus the influences of ultrasound time, different dispersants and quiescent time on the dispersion effect of commercial nano-size TiO2 were investigated and a nano-solution with stable dispersion system, small particle size, and high concentration of TiO2 was prepared.Results indicated that the optimal conditions to prepare the stable nano-size TiO2 sol was firstly to add 500 mg sodium hexametaphosphate (SHMP) as dispersant in 100 mL ultrapure water, and add l00 mg commercial nano-TiO2,then lay it aside for 6 d after the 15 min of ultrasound time.Consequently,the aver- age size and TEM characterization size of nano-size TiO2 sol were at(196±20) nm and 50-80 nm,and the dispersion mass concentration and Zeta-Potential were (61.89 ±5.41 ) mg/L and (-51.3±6.7) mV, respectively.This optimized method could prepare a stable nano-size Ti02 sol with high concentration,which would make a good foundation for the study of environment risk of engineering nano-materials.