Biomimetic superhydrophobic membrane with multi-scale porous microstructure for waterproof and breathable application

The multifunctional membranes with superior waterproofness and breathability have been extensively used in high-end wearable protection, desalination, and the aerospace industry. A multi-layered, biomimetic and superhydrophobic membrane is designed via a facile two-step strategy of phase-conversion and electrospraying. The homogeneous reticular porous microstructure with a stellate spherulite surface formed by introducing sodium chloride (NaCl) during the phase-conversion process provides an effective vapor-permeable channel for the membrane. Zirconium carbide (ZrC)/silica (SiO2) as two-component inorganic powders with different particle sizes can construct bio-inspired, hierarchical, and superhydrophobic layers. Simultaneously, the synergistic interactions between the components can preferably inspire the photo-to-thermal conversion properties of membranes, further accelerating the efficient transport of water vapor. The ultrathin hierarchical nanoporous composite membrane exhibits the excellent breathability of 11.9 kg m−2d−1 and decent waterproofness of 60.71 kPa. An ultrahigh WCA of up to 167.3° gives a stabilized superhydrophobic surface to the high moisture-permeable membrane while possessed robust reusable self-cleaning and photo-to-thermal properties. Furthermore, the superior performances with the tremendous potential for application prospects in various fields.