A highly robust, non-fluorinated, and economical PDMS-based superhydrophobic flexible surface with repairable and flame-retardant properties

Nature-inspired artificial superhydrophobic surfaces have attracted tremendous attention due to their potential applications in various fields. However, the use of toxic chemicals and expensive nanoparticles with limited durability has restricted the practical applications of these surfaces. Here, we proposed a novel and non-fluorinated technique to fabricate robust and flexible polydimethylsiloxane (PDMS)-based superhydrophobic surface. Fabrication involved two simple steps: preparation of superhydrophobic nanoparticles by burning PDMS, and fabrication of flexible superhydrophobic PDMS surface (SPS) by dispersing particles in a solvent containing PDMS solution and curing agent. Effect of PDMS particle content on morphology and wettability was examined and 10 wt.% PDMS nanoparticles demonstrated superior superhydrophobicity with a water contact angle of 156 degrees and sliding angle of similar to 6 degrees. The SPS displayed excellent mechanical robustness in a sandpaper abrasion test and showed no apparent wettability deterioration even when stretched by up to 50%. Additionally, surface maintained outstanding superhydrophobicity even after 300 cycles of mechanical deformation. Impressively, damaged surface can restore its superhydrophobicity after removing the damaged layer using sandpaper abrasion and displayed exceptional chemical, thermal, flame-retardant, and long-lasting superhydrophobic properties. The work provides an innovative, low-cost, and environment-friendly strategy for designing robust and flexible superhydrophobic surfaces that can be used in real-life applications.