Spontaneous emulsification of water in oil at appreciable interfacial tensions
Spontaneous emulsification of water in oil at appreciable interfacial tensions
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DOI：
10.1016/j.colsurfa.2016.05.041
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发表时间：
2017-05
期刊：
影响因子：
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通讯作者：
P. S. Silva;S. Zhdanov;V. Starov;R. Holdich
中科院分区：
文献类型：
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作者：
P. S. Silva;S. Zhdanov;V. Starov;R. Holdich
观察到在煤油中自发形成水性液滴，这通过存在浓度高于CMC的油溶性表面活性剂：Span® 80来促进。在所有研究条件下，煤油/水界面张力均不低于4 mN/m。因此，自发发生该过程不需要超低界面张力。该过程是由水分子转移到溶胀的反胶束引起的。研究了有机相中表面活性剂浓度和水相中NaCl浓度对自发水相液滴形成的影响。对液滴进行了纳米尺寸分析，结果显示液滴尺寸在100至400纳米之间。已证明，水相中盐的存在抑制液滴形成。结果表明，大固着水液滴沉积在煤油相内的疏水基底上溶解在煤油中，通过形成和增长的液滴，在液滴底部形成水膜。
Spontaneous formation of aqueous droplets in kerosene was observed, which was facilitated by the presence of an oil soluble surfactant: Span®80 at concentrations above CMC. Kerosene/water interfacial tension under all conditions studied was not lower than 4 mN/m. Therefore, ultra-low interfacial tension was not required for this process to occur spontaneously. The process was caused by a transfer of water molecules to swollen reversed micelles. The influence of both the surfactant concentration in the organic phase and NaCl concentration in the aqueous phase on spontaneous aqueous droplet formation was investigated. Nano-sizing analyse of the drops was performed, which showed the droplets sizes in between 100 and 400 nm. It is proven that the presence of salt in the aqueous phase inhibits droplet formation. It is shown that big sessile aqueous droplets deposited on a hydrophobic substrate inside the kerosene phase were dissolved in kerosene through formation and growth of droplets, which form an aqueous film at the droplet base.