Limiting Area per Molecule of Nonionic Surfactants at the Water/Air Interface
Limiting Area per Molecule of Nonionic Surfactants at the Water/Air Interface
复制标题
非离子表面活性剂在水/空气界面处每分子的极限面积
作者：
R. Sedev
众所周知1-4乙氧基化非离子表面活性剂在水/空气界面上的吸附遵循以下规则：A是每个分子的极限面积，N是表面活性剂尾部环氧乙烷(EO)链段的数量。四十年前，van Voorst Vader1 对这种行为做出了解释，该解释至今仍在现代表面活性剂文献中重现。 2-4 尽管实验证据支持上述预测，但最初的表述 1 似乎是不正确的。在本注释中，我们重申 van Voorst Vader 的论点，表明它们是不充分的，并基于对良好溶剂中的柔性链有效的缩放公式得出改进版本。 5 “正确”结果与 van Voorst Vader 的版本非常接近，也与现有数据一致。范·沃斯特·维达的描述
It is well-known1-4 that ethoxylated nonionic surfactants adsorbed at the water/air interface comply with the rule where A is the limiting area per molecule and N is the number of ethylene oxide (EO) segments in the surfactant tail. Forty years ago van Voorst Vader1 gave an explanation of this behavior which is still reproduced in modern surfactant literature. 2-4 Although experimental evidence supports the above prediction, the original formulation1 appears to be incorrect. In the present Note we reiterate the arguments of van Voorst Vader, show them to be inadequate, and derive an improved version based on scaling formulas valid for flexible chains in good solvent. 5 The “correct” result is quite close to the version of van Voorst Vader and also agrees with the data available. van Voorst Vader’s Description