Fluorine-free membranes with microspheres and dual-scale fiber networks for highly effective waterproofness and breathability

초록

Growing environmental concerns have led to the development of waterproof and breathable membranes without fluorine, but simultaneously achieving high waterproofing and breathability is challenging. Herein, hierarchical fluorine-free membranes with microspheres, nanofibers and submicron fibers were fabricated by an efficient multi-needle electrospinning method. Through the doping of silicone-modified PU water repellents and PMMA into the PU matrix, the prepared membrane with microspheres (MS) and dual-scale fibers (DSF) achieves outstanding hydrophobicity, evidenced by a water contact angle of 136 degrees with small water adhesion of 108 mu N. Interlaced networks of ultrafine nanofibers (similar to 40 nm diameter) and submicron-scale fibers generate uniformly distributed narrow pores. Concurrently, embedded microspheres support this fibrous network, resulting in a highly porous architecture. The combination of optimized hydrophobicity and specifically designed pore structures endows the MS-DSF membrane with remarkable hydrostatic pressure resistance (88.26 kPa). Meanwhile, the precision-engineered hierarchical structure with high porosity enables superior water vapor transport (6.23 kg m(-2) d(-1)) and air permeance (9.93 mm s(-1)@100 Pa). This fluorine-free membrane shows great potential in various applications, including athletic gear, medical protective equipment, architectural cladding, and digital devices, offering novel insights into the design of eco-friendly waterproof and breathable materials.

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