The superhydrophobic surface has the characteristics of self-cleaning, anti-icing, anti-bioadhesion, drag reduction, oil-water separation, etc., has broad application prospects in practical applications, and has aroused extensive research interest. However, in practice, the product life of artificial superhydrophobic surfaces is significantly shorter than actual expectations, especially during exposure to harsh environments. The root cause is that superhydrophobicity is a synergistic effect of chemical hydrophobicity and micro- and/or nano-scale surface structures with high roughness, and therefore, it has a weak resistance to mechanical wear and impact. Generally, four different strategies are used to solve this problem: (1) The self-repairing ability of the bionic natural superhydrophobic surface;
(2) Use a compliant coating to soften the peak stress through greater elastic deformation, thereby inhibiting irreversible damage;
(3) Design coatings that may fail in a self-similar way;
(4) Use inherently wear-resistant materials or stable media as templates to reduce damage to the surface roughness characteristics. However, in practical applications, superhydrophobic surfaces will still lose superhydrophobicity under wear and impact. Therefore, it is still a huge challenge to prepare a super-hydrophobic surface with wear resistance and impact resistance.
In view of this, the team of Academician Zheng Quanshui of Tsinghua University used a strategy of completely filling the superhydrophobic medium in the 3D microframework to prepare a superhydrophobic microframework nanofiller (MSNF) film with high mechanical stability. The resulting MSNF film not only maintains super-hydrophobicity after impact (approximately 40.2 J kinetic energy), abrasion, scraping by a scraper, and peeling of the circulating tape. In addition, MSNF also has super oleophobicity, which can prevent oil contamination and retain superhydrophobicity under larger bending or twisting. Combining robustness and scalability, MSNF membranes will be used in cars, ships, airplanes and houses in harsh environments, and this strategy can be extended to various inexpensive structured materials (such as porous iron). Related work was published on Advanced Functional Materials as "Microskeleton-Nanofiller Composite with Mechanical Super-Robust Superhydrophobicity against Abrasion and Impact".