A robust grape-like superhydrophobic surface for efficient oil–water separation and anti/de-icing

Abstract

Superhydrophobic coatings are widely regarded as an effective solution to prevent ice accumulation on equipment under extreme climatic conditions. However, in practical applications, these coatings encounter challenges due to mechanical interlocking caused by ice formation from condensed water vapor, leading to reduced anti-icing performance and poor durability. Furthermore, once ice begins to form on the coating's surface, relying solely on the inherent hydrophobic properties of the coating is insufficient to meet the anti-icing and de-icing demands in real applications. In this study, a light/electricity-responsive cotton fabric based on a biomimetic grape-like structure is prepared via cation polymerization, followed by coating with polydimethylsiloxane (PDMS) through chemical vapor deposition to reduce the surface energy of the cotton substrate. The grape-like photo/electrothermal dual-synergistic superhydrophobic cotton fabric exhibits an exceptional water contact angle of 166.9° and a remarkably low sliding angle of only 1.7°. The superhydrophobic cotton fabric also exhibits efficient and stable anti-icing and de-icing performance, delaying the icing time by approximately 1100 s. Upon the application of light and voltage, the surface temperature rapidly increases to about 50 and 60 °C, respectively. In assessments of durability, the constructed fabric displays exceptional mechanical resilience, enduring 35 cycles of washing, 45 cycles of abrasion and 30 cycles of freeze–thaw without significant degradation of its superhydrophobic properties. Additionally, it also shows excellent self-cleaning properties and oil–water separation, maintaining an oil flux of 3181 L m⁻² h⁻¹ with a separation efficiency of up to 99.6%. This remarkable performance can be attributed to the continuous conductive polymer segments formed by the grape-like light-capturing particles of poly(pyrrole) stacked in a layered manner on the coating surface, in conjunction with a durable micro–nano-structure, and the modification of PDMS further enhances the hydrophobicity of the coating.