How to establish the relationship between wetting parameters and the mechanical properties of a flexible thin film

Abstract

Conventional testing methods face limitations in identifying the mechanical properties of flexible film coatings. In this study, the mechanical properties of the polydimethylsiloxane (PDMS) flexible film coating were obtained by analyzing the dynamic wetting process of droplets on the surface. Results showed that the variation of contact angle can be divided into three regions during wetting, and the deformation height of the PDMS film increased rapidly and then decreased. Furthermore, a new model including interfacial tensions and the elastic force was proposed to establish the relationship among contact angle, deformation height and elastic modulus of the coating. The elastic modulus of the coating obtained from this model had an error of less than 10 % compared to the actual value.