Molecular dynamics simulation of supercritical CO2 microemulsion with ionic liquid domains: Structures and properties  

作　　者：Hongyue Zhu Ying Li Hongrui Ren Dan Zhou Jianzhong Yin 

机构地区：[1]State Key Laboratory of Fine Chemicals,School of Chemical Machinery and Safety,Dalian University of Technology,Dalian 116024,China

出　　处：《Chinese Journal of Chemical Engineering》2019年第11期2653-2658,共6页中国化学工程学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(21376045,21506027);Petrochemicals Joint Fund of National Natural Science Foundation of China;China National Petroleum Corporation(U1662130).

摘　　要：Supercritical carbon dioxide microemulsions are great medium to combine two immiscible substances through forming nanoscale polar cores in nonpolar continuous phase with the help of proper surfactants. The properties of microemulsions could be significantly affected by their constituents and structures. In this work, molecular dynamics simulation was implemented to study supercritical carbon dioxide microemulsions containing ionic liquid [bmim][PF6] and water by adding surfactant Ls-36. Results showed that the above components could form spherical aggregates in CO2 bulk phase with [bmim][PF6] and some water as the inner core, surfactant headgroups and water as the intermediate shell, and surfactant tails as the outer shell. The microstructure information about the outer shell was further investigated by defining an angle between the surfactant tail and the normal direction of the aggregate outer surface, which ranged from 78° to 125°. The influence of the ionic liquid content on the size and structure of microemulsions was explored and the best molar ratio between the ionic liquid and surfactant was around 1.25 for getting maximum water solubility.Supercritical carbon dioxide microemulsions are great medium to combine two immiscible substances through forming nanoscale polar cores in nonpolar continuous phase with the help of proper surfactants. The properties of microemulsions could be significantly affected by their constituents and structures. In this work, molecular dynamics simulation was implemented to study supercritical carbon dioxide microemulsions containing ionic liquid [bmim][PF6] and water by adding surfactant Ls-36. Results showed that the above components could form spherical aggregates in CO2 bulk phase with [bmim][PF6] and some water as the inner core, surfactant headgroups and water as the intermediate shell, and surfactant tails as the outer shell. The microstructure information about the outer shell was further investigated by defining an angle between the surfactant tail and the normal direction of the aggregate outer surface, which ranged from 78° to 125°. The influence of the ionic liquid content on the size and structure of microemulsions was explored and the best molar ratio between the ionic liquid and surfactant was around 1.25 for getting maximum water solubility.

关 键 词：Molecular simulation SUPERCRITICAL carbon dioxide MICROEMULSION IONIC liquids Microstructure Structure parameters 

分 类 号：O643.12[理学—物理化学]