Mechanical Stability of PDMS-Based Micro/Nanotextured Flexible Superhydrophobic Surfaces under External Loading

Superhydrophobicity based on the micro- and nanostructures is frangible to external loading. It is a challenging issue for flexible superhydrophobic surfaces to maintain superhydrophobicity while deforming under external loading. Herein, PDMS-based micro/nanotextured flexible surfaces with robust superhydrophobicity were fabricated by an effective and environmentally friendly method. The formation mechanism of the micro/nanotextured structures and the formation reason for 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/nanotextured structures remained unchanged, and only the bottom layer generated cracks under external loading. There were no obvious changes of superhydrophobicity under a tensile strain up to breakage, 500 cycles of bending, and 100 cm height of water droplets and NaCl particle impact. The self-cleaning property was also verified in cleaning the surfaces covered with various contaminants by water droplets. The fabricated PDMS-based micro/nanotextured flexible surfaces with good mechanical stability and self-cleaning property are expected to be applied in flexible electronic devices.