化工学报Issue(7)：2601-2606,6.DOI:10.11949/j.issn.0438-1157.20150104
CO2浓度对混溶态（CO2+正己烷）/盐水界面微观特性的影响
Influence of CO2 fraction on micro interfacial properties of miscible (CO2+n-hexane)/NaCl interface
摘要
Abstract
In the geological carbon dioxide (CO2) sequestration in abandoned oil reservoirs, there usually exists a fluid system including CO2, oil and brine, where the interplay between them is very important for the successful CO2 storage. In this paper, molecular dynamics simulations were carried out to investigate the interfacial characteristics of the CO2, n-hexane and NaCl solution system with different CO2 fractions at the miscible state. CO2 and n-hexane formed a miscible phase, and a clear interface was observed to separate the CO2 and n-hexane mixture with brine. Both the interfacial width and roughness increased with increasing CO2 composition, indicating the stronger interfacial interactions when water molecules contacted with CO2, leading to the reduction of interfacial tension. The surface adsorption of CO2 reached the maximum when CO2 molar fraction equaled to 65%, as well as the deficiency of n-hexane. This implied the surfactant feature of CO2 and the hydrophobicity of n-hexane towards the interface investigated. A special micro structure was observed at the interface, where CO2, water and n-hexane molecules had own preferred arrangement tendency. The special interfacial characteristics found could explain the experimental IFT phenomena and the microstructure variation in the CO2 injecting process, and could provide some theoretical guidance for CO2 sequestration.关键词
超临界CO2/CO2地质封存/界面/分子模拟Key words
supercritical carbon dioxide/CO2 geological storage/interface/molecular simulation分类
化学化工引用本文复制引用
陶璐,赵伶玲,王镜凡..CO2浓度对混溶态（CO2+正己烷）/盐水界面微观特性的影响[J].化工学报,2015,(7):2601-2606,6.基金项目
国家自然科学基金项目（51106027）。 （）
