Swelling-Induced Delamination Causes Folding of Surface-Tethered Polymer Gels
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- 作者：Sachin S. Velankar ; Victoria Lai ; Richard A. Vaia
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2012
- 出版时间：January 25, 2012
- 年：2012
- 卷：4
- 期：1
- 页码：24-29
- 全文大小：296K
- 年卷期：v.4,no.1(January 25, 2012)
- ISSN：1944-8252
文摘
When a polymer film that is weakly attached to a rigid substrate is exposed to solvent, swelling-induced compressive stress nucleates buckle delamination of the film from the substrate. Surprisingly, the buckles do not have a sinusoidal profile, instead, the film near the delamination buckles slides toward the buckles causing growth of sharp folds of high aspect ratio. These folds do not result from a wrinkle-to-fold transition; instead, the film goes directly from a flat state to a folded state. The folds persist even after the solvent evaporates. We propose that patterned delamination and folding may be exploited to realize high-aspect ratio topological features on surfaces through control of a set of boundary constraints arising from the interrelation of film-surface adhesion, film thickness and degree of swellabilty.