A non-fluorinated mechanochemically robust volumetric superhydrophobic nanocomposite

The widespread use of water-repellent superhydrophobic surfaces is limited by the inherent fragility of their micro- and nanoscale roughness, which is prone to damage and degradation. Here, we report a non-fluorinated volumetric superhydrophobic nanocomposites that demonstrate mechanochemical robustness. The nanocomposites are produced through the addition of micro scale diatomaceous earth and nanoscale fumed silica particles to high-temperature vulcanized silicone rubber. The water-repellency of the surface and bulk of nanocomposites having 120 phr of filler was determined based on the water contact angle and contact angle hysteresis. We compared the water-repellency of nanocomposites of differing diatomaceous earth to fumed silica mass ratios. Increasing the amount of diatomaceous earth enhanced the water-repellency of the nanocomposite surface, whereas an increased amount of fumed silica improved the water-repellency of the bulk material. Moreover, increasing the diatomaceous earth/fumed silica mass ratio improved the cross-linking density and hardness values of the nanocomposite. Despite being subjected to a range of mechanical durability tests, including sandpaper abrasion, knife scratching, tape peeling, water jet impact, and sandblasting, the nanocomposite maintained a water contact angle of 163 degrees and contact angle hysteresis of 2 degrees. When the water-repellency of the prepared nanocomposites eventually deteriorated, we restored their superhydrophobicity by removing the upper surface of the nanocomposite. This extraordinary robustness stems from the embedded low surface energy micro/nanostructures distributed throughout the nanocomposite. We also demonstrated the chemical stability, UV resistance, and self-cleaning abilities of the nanocomposite to illustrate the potential for real-life applications of this material. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

This study introduces a non-fluorinated volumetric superhydrophobic nanocomposite with excellent mechanochemical robustness. The water-repellency of the nanocomposites can be adjusted by changing the mass ratio of diatomaceous earth to fumed silica. Furthermore, the nanocomposite maintains high water contact angle and low contact angle hysteresis after undergoing various mechanical durability tests.