连续相酸碱性对正辛醇/水乳液稳定性的影响

Effect of acidity of continuous phase on formation and stability of Octanol-in-water emulsions

用Stber法合成了纳米二氧化硅粒子,用扫描电镜对其形貌和粒径进行了表征;以纳米二氧化硅粒子作为稳定剂制备正辛醇/水乳液,考察了连续相的酸碱性对乳液形成及稳定性的影响。结果表明:纳米二氧化硅粒子呈规则球形,平均粒径为110 nm;随着连续相中盐酸浓度逐渐增加,乳液液滴平均粒径由2μm增加到13μm,乳液稳定时间由1 h增加到60 d以上;随着连续相中氢氧化钠浓度逐渐增加,乳液稳定时间由1 h下降到20 min.连续相酸碱性的变化改变了二氧化硅纳米粒子的荷电性能和絮凝行为,进而影响了乳液的形成和稳定性。

Nano-silica particles were prepared via an Stober method. Octanol-in-water emulsions stabi- lized by nano-silica particles were prepared. The effect of the acidity of the continuous phase on the formation and stability of the emulsions were investigated. The results showed that the nano-silica particles were sphere shaped with an average diameter of 110 nm. The stabilization time of the emulsion increased from 1 h to more than 60d with the increasing of the concentration of the hydrochloric acid in the continuous phase, while the stabilization time of the emulsion declined from 1 h to 20min with the increasing of the sodium hydroxide concentration. The influence of the acidity of the continuous phase on the stability of the Picketing emulsions could be ascribed to the changing of the electric charge density and the flocculation behavior of the nano-silica particles.