Mechanical Stability of PDMS-based Micro/Nano-Textured Flexible Superhydrophobic Surfaces under External Loading.

Abstract

Superhydrophobicity based on the micro- and nano-structures is frangible to external loading. It is a challenged issue for flexible superhydrophobic surfaces to maintain superhydrophobicity while deforming under external loading. Herein, PDMS-based micro/nano-textured flexible surfaces with robust superhydrophobicity were fabricated by an effective and environmentally friendly method. The formation mechanism of the micro/nano-textured structures and the formation reason of superhydrophobicity were investigated. The effects of reaction time on wettability were also explored. Besides, the changes of morphology and superhydrophobicity under external loading were studied. It is found that micro/nano-textured structures maintained unchanged, and only the bottom layer generated cracks under external loading. There were no obvious change of superhydrophobicity under a tensile strain up to breaking, 500 cycles of bending, and 100 cm height of water droplets and NaCl particles impacting. Self-cleaning property was also verified in cleaning the surfaces covered with various contaminants by water droplets. The fabricated PDMS-based micro/nano-textured flexible surfaces with good mechanical stability and self-cleaning property are expected to be applied in flexible electronic devices.