石油化工高等学校学报

石油化工高等学校学报

• 油气储运 • 上一篇    下一篇

POA分子在纳米SiO2颗粒表面吸附的分子动力学模拟

李传宪1王璐1姚博1郭策2程浩3杨 飞1孙广宇1   

  1. (1. 中国石油大学(华东) 储运与建筑工程学院,山东 青岛 266580;2. 中国石油青海油田分公司管道输油处,青海 格尔木 816000; 3. 中国石油青海油田分公司采气一厂,青海 格尔木 816000 )
  • 收稿日期:2017-08-26 修回日期:2017-09-06 出版日期:2018-10-26 发布日期:2018-11-02
  • 通讯作者: 孙广宇(1987⁃),男,博士,讲师,从事原油乳化及破乳方面的研究;E⁃mail:sunguangyu@upc.edu.cn
  • 作者简介:李传宪(1963?),男,博士,教授,从事油气长距离管输方面的研究;E?mail:lchxian@upc.edu.cn
  • 基金资助:
    国家自然科学基金(51204202);山东省自然科学基金(ZR2016EEM22);中央高校基本科研业务费专项资金资助(17CX06019)

Molecular Dynamics Simulation of Adsorption Behavior of POA on the Surface of SiO2 Nanoparticles

Li Chuanxian1Wang Lu1Yao Bo1Guo Ce2Cheng Hao3Yang Fei1Sun Guangyu1   

  1. (1. College of Pipeline and Civil Engineering,China University of Petroleum,Qingdao Shandong 266580,China ; (2. Pipeline Transportation Department of PetroChina Qinghai Oilfield Company,Ge’ermu Qinghai 816000,China ; 3. No.1 Gas Production Plant of PetroChina Qinghai Oilfield Company,Ge’ermu Qinghai 816000,China)
  • Received:2017-08-26 Revised:2017-09-06 Online:2018-10-26 Published:2018-11-02

摘要: 采用分子动力学方法(MD)研究模拟含蜡原油环境中聚丙烯酸十八酯(POA)分子在甲基改性纳米SiO2颗粒表面的吸附行为,构建了包含POA分子的模拟含蜡原油体系在三种不同甲基改性程度的纳米SiO2颗粒表面的吸附模型,分析了吸附能、密度分布、均方位移、径向分布函数等参量。结果表明,未改性的颗粒表面最先吸附沥青质等极性较强的物质;100%甲基改性的颗粒表面最先吸附烷烃;50%甲基改性的颗粒表面最先吸附芳香烃、POA,且50%甲基改性表面更有利于POA分子的稳定吸附,有利于POA分子形成侧链伸展更好的吸附构型。研究也发现,在50%甲基改性的颗粒表面,POA分子与蜡分子(C24H50)之间的相互作用最强,C24H50分子的分布最聚集。此研究为纳米杂化降凝剂中纳米颗粒的有机实验改性提供了理论指导,为聚合物/纳米颗粒降凝剂的作用机理研究提供了方法。

关键词: POA, 吸附, 甲基改性, 纳米SiO2颗粒, 分子动力学模拟

Abstract: In this paper, the adsorption behavior of polyoctadecyl acrylate (POA) in model crude oil on the surface of nano⁃SiO2 particles modified by methyl was investigated by performing molecular dynamics (MD) simulations. The adsorption model of model crude oil including POA molecule on the surface of nano⁃SiO2 particles was constructed. The model crude oil consists of asphaltene, resin, aromatic hydrocarbons and alkanes. The surface of nano⁃SiO2 particles was modified with three different degree of methyl. Several parameters such as the adsorption energy, relative density distribution, the mean square displacement and radial distribution function were analyzed. The results show that the unmodified surface is firstly adsorbed by asphaltene of strong polarity while the surface of 100% methyl⁃modified is firstly adsorbed by n⁃alkanes. The surface of 50% methyl⁃modified particles is firstly adsorbed by aromatic hydrocarbons. The results also indicate that the surface of 50% methyl⁃modified particles is not only more conducive to the stable adsorption of POA molecules, but also conducive to POA molecules to form a better adsorption configuration. What’ more, on the surface of 50% methyl⁃modified particles, the interaction between POA molecule and C24H50 molecules is stronger, and the distribution of C24H50 molecules is more aggregated. Finally, the study of this paper provides a method for studying the mechanism of pour point depressants composed of polymer and inorganic nanoparticle and provides theoretical guidance for the experimental modification of nanometer particles in nano⁃hybrid pour point depressant.

Key words: POA, Adsorption, Methy modification, Nano?SiO2 particle, Molecular dynamics simulation