Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Phys Rev Lett. 2012 Jul 20;109(3):038001. doi: 10.1103/PhysRevLett.109.038001. Epub 2012 Jul 16.
In a soft elastic film compressed on a stiff substrate, creases nucleate at preexisting defects and grow across the surface of the film like channels. Both nucleation and growth are resisted by the surface energy, which we demonstrate by studying creases for elastomers immersed in several environments--air, water, and an aqueous surfactant solution. Measurement of the position where crease channeling is arrested on a gradient thickness film provides a uniquely characterized strain that quantitatively reveals the influence of surface energy, unlike the strain for nucleation, which is highly variable due to the sensitivity to defects. We find that these experimental data agree well with the prediction of a scaling analysis.
在被压缩在刚性基底上的柔软弹性薄膜中，褶皱在预先存在的缺陷处成核，并像通道一样在薄膜表面扩展。成核和生长都受到表面能的阻碍，我们通过研究浸入几种环境（空气、水和水基表面活性剂溶液）的弹性体中的褶皱来证明这一点。在梯度厚度的薄膜上测量褶皱通道停止的位置，可以提供一种独特的应变，这种应变可以定量地揭示表面能的影响，而不像成核应变那样，由于对缺陷的敏感性而变化很大。我们发现这些实验数据与标度分析的预测非常吻合。
