INTERFACIAL FRICTION OF WETTED MONOLAYERS
INTERFACIAL FRICTION OF WETTED MONOLAYERS
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DOI：
10.1016/0043-1648(94)90168-6
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发表时间：
1994-06-01
期刊：
影响因子：
5
通讯作者：
MAZUYER, D
中科院分区：
文献类型：
--
作者：
GEORGES, JM;TONCK, A;MAZUYER, D
一种“分子摩擦计”已经被建造出来[1]，它可以非常精确地直接测量在液体介质中承载有机层的金属表面之间相互滑动时作用的力和位移。它的独创性是由于它的低顺应性（对于法线方向为2 × 10（-7）m N-1，对于其他两个方向为2 × 10（-6）m N-1），这允许对薄层进行机械控制。在这项工作中，它示出的各向异性的薄单层的硬脂酸吸附的每个钴表面是更符合比钴表面的接触，从而降低了接触区的表观剪切模量和控制的剪切过程。“界面”摩擦力取决于滑动速度，并且对膜界面厚度的非常小的变化非常敏感。两个竞争和相反的过程中发生的滑动：单分子层的破碎和提升。这表明，破碎出现在很低的速度，当渡越时间接近的分子单层。我们的研究结果有直接的应用边界润滑剂的性能和表面活性剂和聚合物分子的流变行为。
A ''molecular tribometer'' has been constructed [1] that measures directly, with great accuracy, the forces and the displacements that act between metallic surfaces bearing organic layers in a liquid medium as they slide past each other. Its originality is due to its low compliances (2 x 10(-7) m N-1 for the normal direction, 2 x 10(-6) m N-1 for the two other directions), which permit mechanical control of the thin layer. In this work, it is shown that an anisotropic thin monolayer of stearic acid adsorbed an each cobalt surface is more compliant than the contact of the cobalt surfaces and hence reduces the apparent shear moduli of the contact zone and controls the shear process. The ''interfacial'' friction depends on the sliding speed and is very sensitive to the very small variations of the film interface thickness. Two competitive and opposing processes occur during the sliding: crushing and lifting of the monolayer. It is suggested that the crushing appears at very low speed, when the transit time is close to that of the molecules monolayer. Our findings have direct applications for the properties of boundary lubricants and for the rheological behaviour of both surfactant and polymer molecules.