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| 羟基化及硅烷化二氧化硅表面润湿行为的分子模拟 |
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任红梅1,2,孟庆春1,2,范忠钰2,刘媛2,曾庆桥2,胡松青3
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(1.华东理工大学化工学院,上海 200237;2.华北油田公司勘探开发研究院,河北任丘 062552;3.中国石油大学理学院,山东青岛 266580)
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| 摘要: |
| 采用分子动力学模拟方法研究水团簇在羟基化及不同链长硅烷化二氧化硅表面的微观润湿行为,通过相互作用能、径向分布函数及扩散系数等参量对微观润湿机制进行分析。结果表明:羟基化二氧化硅表面具有极强亲水性,而硅烷化表面疏水性较强,且疏水性随烷基链增加呈增强趋势;羟基化二氧化硅表面与水分子存在强相互作用,使团簇底部水分子优先向表面移动,并带动其余水分子向表面迁移,促进水团簇在表面铺展,表现出强亲水性;硅烷化二氧化硅表面与水之间主要为范德华作用,不足以克服团簇内部相互作用而破坏水滴结构,表现出强疏水性,随着烷基链增长,表面与水分子的相互作用强度逐渐减弱,疏水性增强。 |
| 关键词: 界面 二氧化硅 羟基化 硅烷化 分子模拟 |
| DOI：10.3969/j.issn.1673-5005.2014.05.025 |
| 分类号::O 647 |
| 基金项目:国家自然科学基金项目(51034007,1)；中石油智能纳米驱油剂项目(2011A-1001)；中国石油大学(华东)自主创新项目(14CX02002A, 14CX06004A) |
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| Molecular simulation of wetting behavior on hydroxylation and silanization SiO2 surface |
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REN Hongmei1,2, MENG Qingchun1,2, FAN Zhongyu2, LIU Yuan2, ZENG Qingqiao2, HU Songqing3
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(1.College of Chemical Engineering in East China University of Science and Technology, Shanghai 200237, China;2.Exploration and Development Research Institute, Huabei Oilfield Company, Renqiu 062552, China;3.College of Science in China University of Petroleum, Qingdao 266580, China)
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| Abstract: |
| The microscopic wetting behavior of water on silica surface was investigated by molecular dynamics simulation, in which the hydroxylation surface and silanization surfaces with different alkyl chain length were considered. And the wetting mechanism was analyzed using interaction energy, radial distribution function and diffusion coefficient. It is observed that the hydroxylation surface has strong hydrophilicity. However, the silanization surface exhibits hydrophobicity, and the hydrophobicity is enhanced with lengthened alkyl chain. Also the results indicate that the water cluster has strong interaction with hydroxylation silica surface, which makes the water molecules in the bottom of cluster move towards surface preferentially. In this way the pre-absorbed water molecules would promote the adsorption of the rest water molecules. Then, the water cluster spreads completely on hydroxylation silica surface, and exhibits strong hydrophobicity. On the contrary, the interaction between water cluster and silanization SiO2 surface is mainly originated from van der Waals potential, which cannot overcome the hydrogen-bond interaction between water cluster, and presents strong hydrophobicity. With the increase of alkyl chain length, the van der Waals potential between water cluster and silanization surface becomes weak, and the hydrophobicity is improved. |
| Key words: interface silica hydroxylation silanization molecular simulation |
