Hydrophobic Attraction Measured between Asymmetric Hydrophobic Surfaces
Hydrophobic Attraction Measured between Asymmetric Hydrophobic Surfaces
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DOI：
10.1021/acs.langmuir.7b04246
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发表时间：
2018-03-27
期刊：
影响因子：
3.9
通讯作者：
Craig, Vincent S. J.
中科院分区：
文献类型：
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作者：
Ishida, Naoyuki;Matsuo, Kohei;Craig, Vincent S. J.
用胶体探针原子力显微镜(AFM)测量了不同疏水程度的二氧化硅表面之间的相互作用力。用十八烷基三氯硅烷(OTS)制备了一种高度疏水的二氧化硅颗粒，并测量了它们与表面疏水性不同的二氧化硅基质之间的相互作用力。高度疏水的颗粒和完全亲水的硅片表面之间的相互作用力很好地符合DLVO理论，表明表面之间没有额外的(非DLVO)力。当硅片表面被处理成水在表面上的接触角为40时，表面之间观察到比范德华力范围更大的附加引力。吸力的范围和大小随着水在衬底上的接触角的增大而增大。除了对接触角的影响外，基板上疏水层的碳氢链长度和端基对作用力的大小影响很小，即使当基板上的极性羧基终止时，只要另一表面的疏水性较高。
The interaction forces between silica surfaces modified to different degrees of hydrophobicity were measured using colloidal probe atomic force microscopy (AFM). A highly hydrophobic silica particle was prepared with octadecyltrichlorosilane (OTS), and the interaction forces were measured against silica substrates modified to produce surfaces of varying hydrophobicity. The interaction forces between the highly hydrophobic particle and a completely hydrophilic silicon wafer surface fitted well to the DLVO theory, indicating that no additional (non-DLVO) forces act between the surfaces. When the silicon wafer surface was treated to produce a contact angle of water on surface of 40, an additional attractive force that is longer ranged than the van der Waals force was observed between the surfaces. The range and magnitude of the attractive force increase with the contact angle of water on the substrate. Beyond the effect on the contact angle, the hydrocarbon chain length and the terminal groups of hydrophobic layer on the substrate only have a minor effect on the magnitude of the force, even when the substrate is terminated with polar carboxyl groups, provided the hydrophobicity of the other surface is high.