Thickness Dependence of the Young's Modulus of Polymer Thin Films
Thickness Dependence of the Young's Modulus of Polymer Thin Films
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DOI：
10.1021/acs.macromol.8b00602
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发表时间：
2018-09-11
期刊：
影响因子：
5.5
通讯作者：
Russell, Thomas P.
中科院分区：
文献类型：
--
作者：
Chang, Jooyoung;Toga, Kamil B.;Russell, Thomas P.
聚合物薄膜的杨氏模量从厚度为微米的本体膜到具有类似于6 nm的厚度的膜（其小于回转半径Rg）测量。一种简单的，非侵入性的技术，在相同的几何形状，即，在水表面上的自由浮动膜与膜表面上的水滴的摩擦用于测定在该非常大的膜厚度范围内的模量。与固体基底不同，除了在膜的边界处之外，不存在由下面的液体基底施加在膜上的面内应力。使用最近的理论发展，在治疗皱纹现象，我们提取的膜模量的皱纹长度的测量。杨氏模量没有显示出任何系统的变化与膜厚度，从最厚的散装膜下降到膜的厚度类似于R-g的PS和PMMA，虽然轻微增加的杨氏模量被发现为最薄的子R-g厚的PS膜。
The Young's modulus of polymer thin films was measured from bulk films that are micrometers in thickness down to films having a thickness of similar to 6 nm, which is less than the radius of gyration, R g . A simple, noninvasive technique in the same geometry, i.e., the wrinkling of a free-floating film on a water surface with a droplet of water on the surface of the film, was used to determine the modulus over this very large range of film thicknesses. Unlike a solid substrate, there are no in-plane stresses exerted on the film by the underlying liquid substrate except at the boundary of the film. Using recent theoretical developments in the treatment of wrinkling phenomena, we extracted the film modulus from measurements of the wrinkle length. The Young's modulus does not show any systematic change with film thickness, from the thickest bulk films down to films with a thickness of similar to R-g for both PS and PMMA, although a slight increase of the Young's modulus was found for the thinnest sub-R-g thick PS film.