Preparation Of Free-Standing Elastomer Films And Observations Of Oscillatory Cracking Patterns

Abstract

In this thesis, we present a novel method of fabricating free-standing elastomer films of micron to sub-micron thickness. The films are prepared on top of a sacrificial layer, which is used to facilitate separation from the substrate. After the elastomers are cured, polymer chains remain unbound to the cross-linked network of the elastomer. The unbound chains are removed via solvent extraction prior to the separation of the elastomer from the substrate. Once removed from the substrate, the elastomer films are transferred to a support washer. Ellipsometry measurements of the elastomer films on a substrate reveal that the solvent extraction removes 41% of the thickness of the films in unbound chains, on average. This thesis also presents a preliminary study of a system displaying fascinating oscillatory crack formation that was observed serendipitously. We hypothesize that the cracks form due to a combination of fracture and film delamination.