Variation of Frictional Forces in Air with the Compositions of Heterogeneous Organic Surfaces
Variation of Frictional Forces in Air with the Compositions of Heterogeneous Organic Surfaces
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DOI：
10.1021/la990782d
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发表时间：
2000
期刊：
影响因子：
3.9
通讯作者：
Ben D. Beake and;G. Leggett
中科院分区：
文献类型：
--
作者：
Ben D. Beake and;G. Leggett
用原子力显微镜研究了非均相有机材料的摩擦特性。由极性基团和非极性基团组成的混合自组装单分子膜在空气中的摩擦系数与推进水接触角的余弦之间有很好的相关性。对于这些化学非均质材料，摩擦力与表面自由能成正比。对于含有甲基末端基团的短链和长链硫醇的混合单分子膜，摩擦力有很大的增加，这归因于烷基链无序而不是表面能效应。经等离子体处理的聚酯薄膜在空气中的摩擦系数与进水角的余弦之间存在非线性关系。这被认为反映了等离子体处理的薄膜表面的机械性能的变化，以及在这些更复杂的材料上观察到的表面能量的增加。
The frictional properties of heterogeneous organic materials have been investigated by atomic force microscopy. There is a good correlation between measurements of the friction coefficient in air and the cosines of the advancing water contact angles for mixed self-assembled monolayers composed of polar and nonpolar groups. The friction force is proportional to the surface free energy for these chemically heterogeneous materials. For mixed monolayers containing short and long chain thiols with methyl terminal groups there is a large increase in friction, attributed to alkyl chain disorder rather than a surface energy effect. There is a nonlinear relation between friction coefficient measurements in air and the cosines of the advancing water contact angles on plasma-treated polyester films. This is thought to reflect a contribution from the changed mechanical properties of the plasma-treated film surface in addition to the observed surface energy increase on these more complex materials.