Biomimetic Structured Polymeric Nanosheet/Nanofiber Membranes Enable Robust Waterproofness and Breathability

Abstract Skin‐like fibrous materials with water‐resistant and moisture‐permeable capabilities have played a pivotal role in human health and economic development. However, most existing waterproof‐breathable nanofiber materials face a daunting trade‐off dilemma of waterproofness and breathability. Herein, novel biomimetic structured (purslane‐like) nanofiber membranes are reported with simultaneously improved waterproofness and breathability enabled by the in situ incorporation of unique polymeric nanosheets via synchronized electrospinning–electrospraying strategy based on polymer solutions. The electrospun polyamide nanofiber membranes are endowed with purslane‐like hierarchical rough micro/nano‐structures by introducing electrosprayed fluorinated polyurethane nanosheets to generate desirable superhydrophobicity. Meanwhile, stacking cavities triggered by the nanosheets with a large diameter (micrometer scale) provide purslane‐like membranes with higher porosity and more passageways to transport moisture and air efficiently. Benefiting from the abundant superhydrophobic microchannels, the resulting nanosheet‐embedded nanofiber membranes exhibit robust waterproofness with hydrostatic pressure of 121 kPa and high breathability with a water vapor transmission rate of 12.9 kg m −2 d −1 and air permeability of 15.6 mm s −1 . This synchronized electrospinning–electrospraying strategy for achieving purslane‐like structures can open opportunities for the development of future advanced fibrous materials for various applications.