Highly Flexible Superhydrophobic Poly(Urethane Acrylate) Film for Applications Requiring High Optical Transparency

The present work elucidates the successful attempts toward the development of a highly transparent, flexible, and superhydrophobic (HTFS) film. The HTFS film is obtained by introducing graphene oxide (GO) into micropillar‐patterned poly(urethane acrylate) (PUA), followed by siloxane functionalization via chemical vapor deposition. The fabricated SPG2 film (siloxane‐functionalized PUA incorporated with 0.1 wt% of GO) exhibits a water advancing contact angle, water receding contact angle, and sliding angle of 155.5 ± 0.3°, 143.4 ± 0.6°, and 9 ± 0.4°, respectively. The SPG2 film also exhibits an optical transmittance of ≈84% at 550 nm. Mechanical wearable tests demonstrate no significant degradation in the self‐cleaning properties and optical transparency. The fabricated HTFS film (SPG2) is used as a protective layer for a solar module. This solar module shows improved power conversion efficiency (PCE) compared to that of a bare solar module owing to the high optical transparency and light‐trapping effect of the fabricated film that reduce the light reflectance. Furthermore, the SPG2‐protected solar cell demonstrates superior PCE under different surface contamination conditions comparing to other cells. The fabricated micropatterned SPG2 film can be used for various outdoor applications that require high optical transparency, flexibility, and superior self‐cleaning performance. A highly transparent, flexible, and superhydrophobic film is fabricated by a facile technique with micropillar‐patterned PG (composite material of poly(urethane acrylate), PUA and graphene oxide, GO), and uses polydimethylsiloxane (PDMS) as the source to functionalize the patterned surface through chemical vapor deposition (CVD). The hydroxyl group in GO plays a key role in covalently bonding the siloxane groups to the PG surface.