Attractive forces between uncharged hydrophobic surfaces: direct measurements in aqueous solution.
Attractive forces between uncharged hydrophobic surfaces: direct measurements in aqueous solution.
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DOI：
10.1126/science.4035349
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发表时间：
1985-09
期刊：
影响因子：
56.9
通讯作者：
R. Pashley;P. McGuiggan;B. Ninham;D. F. Evans
中科院分区：
文献类型：
--
作者：
R. Pashley;P. McGuiggan;B. Ninham;D. F. Evans
长链双链烷基醋酸铵表面活性剂可溶于水，在合适的条件下，可吸附在白云母片上，形成电中性疏水表面。在这些表面之间测量到的引力，在距离D达到约10纳米的范围内，比范德瓦尔斯理论预期的要强10到100倍。力按指数衰减[力与exp(-D/1.4)成正比]，而不是遵循连续介质理论的幂定律行为。这些和早期实验的结果表明，这些引力的强度主要取决于表面的疏水程度，并归因于表面对水结构的长期影响。此外，对于疏水性很强的表面，描述了将表面拉开的空化效应。
Long, double-chained alkylammonium acetate surfactants are soluble in water and, under suitable conditions, adsorb onto sheets of muscovite mica, forming an electrically neutral, hydrophobic surface. Attractive forces measured between such surfaces are 10 to 100 times stronger than expected from van der Waals theory over distances D up to about 10 nanometers. The forces decay exponentially [with a force proportional to exp(-D/1.4)] instead of following the power-law behavior of continuum theory. The results of these and earlier experiments indicate that the strength of these attractive forces depends critically on the degree of hydrophobicity of the surface and is due to the long-range influence of the surface on the structure of water. In addition, for very hydrophobic surfaces, the cavitation effects on pulling the surfaces apart are described.