Hydrophobicity and anti-icing performances of nanoimprinted and roughened fluoropolymers films under overcooled temperature

Abstract

Superhydrophobic (SH) surfaces are promising materials to limit frost, ice and snow formation on cold surfaces submitted to low temperature conditions. Inspired by the hierarchical roughness of lotus leaves, SH surfaces have received great attention in recent years. In this work, FEP (Fluorinated Ethylene Propylene) flexible films are chosen for their intrinsic hydrophobicity and their capability to cover non-flat surfaces with nanostructures. In the context of the use of superhydrophobic surfaces for anti-icing applications, it is essential to confirm that SH surfaces at room temperature retain their properties under overcool condition at −15°C. To this aim hydrophobic performances have been explored by contact angle and contact angle hysteresis measurements in these two conditions of temperature. In order to make these films SH, two methods were investigated. First, FEP has been imprinted by nanoimprint lithography (NIL) with different structures. In another way, plasma treatment etching was used to obtain rough surface structures. Thus, we evaluated the performances of several imprinted and rough surfaces for the use of hydrophobic and SH surfaces in the context of anti-icing applications.