The present work focuses on a sustainable approach to transform rice-husk waste into self-healing superhydrophobic films with potential application for drag-reduction and oil absorption. Rice husk was transformed into amorphous nano silica particles (d₅₀ ∼ 150 nm) exhibiting mesoporosity with a surface area of 400 m²/g. Superhydrophobic films fabricated using a solvent-less approach showed the transition from flattened to nano-globular morphology with increasing silica content in polydimethylsiloxane (PDMS), leading to exceptional superhydrophobicity. The optimized film with a particle fraction of 60 % exhibited high de-wetting (> 150º) and mechanical strength (∼7 MPa). The film showed extremely low water droplet adhesion of ∼19 μN, similar to lotus leaf owing to high negative Laplace pressure. Significantly, the film exhibited persisting de-wettability and endurance under harsh chemical, thermal, and mechanical conditions. The robustness is further fortified with room temperature self-healing and real-time self-regeneration characteristics, persisting even after exposure to strong acids and significant abrasion. The multidimensional aspects of the film embarked with a 70 % drag reduction and effective oil-water separation. The present work not only provides a sustainable pathway for managing agricultural waste but also a practical and easy-to-implement approach to tackle oil spill incidents.

中文翻译：

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稻壳衍生的自修复超疏水薄膜，使用无溶剂方法降低阻力和吸油性能


目前的工作重点是将稻壳废料转化为自修复的超疏水膜，具有减少阻力和吸油的潜在应用。稻壳转化为无定形纳米二氧化硅颗粒 （d₅₀ ∼ 150 nm），表现出表面积为 400 m²/g 的介孔性。使用无溶剂方法制备的超疏水薄膜显示，随着聚二甲基硅氧烷 （PDMS） 中二氧化硅含量的增加，从扁平形态转变为纳米球状形态，从而导致出色的超疏水性。颗粒分数为 60% 的优化薄膜表现出高脱湿性 （> 150º） 和机械强度 （∼7 MPa）。该薄膜显示出 ∼19 μN 的极低水滴粘附力，由于拉普拉斯负压高，与荷叶相似。值得注意的是，该薄膜在恶劣的化学、热和机械条件下表现出持续的去润湿性和耐久性。室温自愈和实时自再生特性进一步加强了稳健性，即使在暴露于强酸和严重磨损后仍能持续存在。薄膜的多维方面减少了 70% 的阻力并有效地分离了油水。目前的工作不仅为管理农业废弃物提供了一条可持续的途径，而且还为解决溢油事件提供了一种实用且易于实施的方法。