Thickness Dependence of the Young’s Modulus of Polymer Thin Films

• DOI: 10.1021/acs.macromol.8b00602
• Publication Date: 2018-08-23T19:05:14Z
• Authors: Jooyoung Chang; Kamil B. Toga; Joseph D. Paulsen; Narayanan Menon; Thomas P. Russell
• Keywords: Radius of gyration

The Young's modulus of polymer thin films was measured from bulk that are micrometers in thickness down to having a ∼6 nm, which is less than the radius gyration, Rg. A simple, noninvasive technique same geometry, i.e., wrinkling free-floating film on water surface with droplet film, used determine over this very large range thicknesses. Unlike solid substrate, there no in-plane stresses exerted by underlying liquid substrate except at boundary film. Using recent theoretical developments treatment phenomena, we extracted measurements wrinkle length. does not show any systematic change thickness, thickest ∼Rg for both PS and PMMA, although slight increase found thinnest sub-Rg thick