期刊
SOFT MATTER
卷 16, 期 12, 页码 2994-3004出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/c9sm01892a
关键词
-
类别
资金
- SERDP project [WP18-1031]
- National Science Foundation through the National Nano Co-ordinated Infrastructure Network (NNCI) [ECCS-1542202]
Many liquid-liquid emulsions, including shipboard oily bilgewater (oil-in-water) and water entrained in diesel fuels (water-in-oil), are chemically stabilized by surfactants and additives and require treatment to destabilize and separate. The interfacial tension (IFT) of surfactant-laden interfaces between the continuous and dispersed phase, as well as the size of the dispersed droplets, are significant factors in determining emulsion stability. In particular, the timescale associated with a dynamic change in IFT due to surfactant transport is indicative of how fast the emulsion will stabilize. In the present work, the dynamic IFT of droplets at micro-scale (similar to 80 mu m) and milli-scale (similar to 2 mm) is measured with simulated bilgewater with soluble surfactant systems. It is found that the IFT of micro-scale droplets decays faster than that of the milli-scale droplets due to smaller diffusion boundary layer thickness. The change in IFT was also studied for water-soluble surfactants added into the dispersed phase and continuous phase for both milli- and micro-scaled droplets. The results show that the IFT of micro-scale droplets decreases to the equilibrium value faster when the surfactant is in outer phase than in the inner phase, while the IFT does not change significantly for the milli-scale droplets. The observations are explained by the change in diffusion limited to kinetic limited surfactant transport. Finally, the surfactant diffusivities, adsorption and desorption rate constants are calculated using Langmuir's equation. The results presented here provide insight into the fundamental mechanism of the surfactant transport and helps improve mitigation strategies of oil-water emulsions.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据