CIESC Journal ›› 2023, Vol. 74 ›› Issue (4): 1651-1659.DOI: 10.11949/0438-1157.20230086

• Surface and interface engineering • Previous Articles     Next Articles

AFM study of the interaction forces between micro-oil droplets and modified silica surfaces in multiphase dispersion systems

Yuntong GE1(), Wei WANG1(), Kai LI1,2, Fan XIAO1, Zhipeng YU1, Jing GONG1   

  1. 1.Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, Ministry of Education Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing 102249, China
    2.School of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050, Gansu, China
  • Received:2023-02-08 Revised:2023-03-29 Online:2023-06-02 Published:2023-04-05
  • Contact: Wei WANG


葛运通1(), 王玮1(), 李楷1,2, 肖帆1, 于志鹏1, 宫敬1   

  1. 1.中国石油大学(北京)城市油气输配技术北京市重点实验室,天然气水合物国家重点实验室,石油工程教育部重点实验室,北京 102249
    2.兰州理工大学石油化工学院,甘肃 兰州 730050
  • 通讯作者: 王玮
  • 作者简介:葛运通(1995—),男,博士研究生,
  • 基金资助:


The interaction between micro-oil droplets and solid surfaces in multiphase dispersion systems affects the productivity of many industrial processes such as oil-water separation, wastewater treatment and anti-oil-fouling. Investigating the mechanism of micromechanical interactions between oil droplets and surfaces of different properties in aqueous solutions is of substantial significance. However, it is still challenging to directly measure the interaction forces between micron-sized droplets and surfaces. In the present work, microscopic forces between micron-sized n-tetradecane oil droplets and hydroxylated or aminated modified silica surfaces in aqueous solutions were measured by using atomic force microscope (AFM) droplet probe techniques. The effects including interaction velocity, surface potential, ionic strength, pH and various surfactants on the interaction between oil droplets and surfaces in aqueous solutions were systematically investigated. The results showed that the hydroxylated silica surface was strongly negatively charged, while the surface electronegativity was weakened after the (3-aminopropyl)triethoxysilane (APTES) amination modification. At weak surface electronegativity, high ionic strength and acidic conditions, oil droplets in the dispersed phase are tended to attach to the surface under attractive forces such as van der Waals (VDW) due to the suppression of double electric layer (EDL) repulsion. The hydrodynamic force between the oil droplets and the surface enhances with the increase of the interaction velocity. The anionic surfactant sodium dodecyl sulfate (SDS) enhances the negative potential at the oil-water interface, allowing it to be more efficient than the cationic surfactant cetyltrimethylammonium bromide (CTAB) in maintaining the stability between the oil droplets and the silica surface. Meanwhile, the steric repulsion generated by the blocked polymer Pluronic F68 can effectively inhibit the attachment between oil droplets and surfaces in aqueous solutions. The research results help to further reveal the interaction mechanism between the oil droplet and the surface.

Key words: atomic force microscope, oil droplet, microscale, silica, modification, surfactants, force


多相分散体系广泛存在于石油、化工、新能源等众多领域,研究其微观力学作用机理具有重要意义,但对微米级液滴与表面间作用力的直接测量仍存在挑战。利用原子力显微镜液滴探针方法测量了水溶液中微米级油滴与羟基化和氨基化改性二氧化硅表面间的微观作用力。结果表明,在高盐浓度、酸性环境下由于双电层斥力被削弱,油滴更容易在范德华引力下与表面聚结;相较于羟基化二氧化硅表面,油滴与氨基化二氧化硅表面更容易聚结;阴离子表面活性剂十二烷基硫酸钠对油滴与表面的阻聚效果优于阳离子型表面活性剂十六烷基三甲基溴化铵;聚合物Pluronic F68产生的空间位阻效应有助于油滴与表面间的稳定。研究成果有助于进一步揭示油滴与表面间的相互作用机理。

关键词: 原子力显微镜, 油滴, 微尺度, 二氧化硅, 改性, 表面活性剂, 作用力

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