Fluorine-Free Nanofiber/Network Membranes with Interconnected Tortuous Channels for High-Performance Liquid-Repellency and Breathability.

Abstract

The excessive use of fluoride in fibrous membranes poses significant bioaccumulative threats to the environment and human health. However, most existing membranes used in protective clothing and desalination systems show high fluorine dependence and inevitable trade-offs between liquid repellency and breathability. Herein, fluorine-free bonded scaffolded nanofiber/network membranes are developed using the electro-coating-netting technique to achieve high-performance liquid-repellency and breathability. By manipulating the stretching of electrospun jets and the polarization of electrets, rough and electrostatic wetting nanofibers are obtained as scaffolds, on which long-chain alkyl precursors are coated to assemble 2D networks consisting of nanowires with diameters of ∼42 nm and bonding points. The resultant fluorine-free membranes exhibit small pore sizes of ∼460 nm, highly interconnected tortuous channels, a water contact angle of ∼138°, and elastic elongation up to 300%, thereby providing both high-performance liquid repellency (125 kPa) and vapor permeability (4206 g m^-2 d^-1), making them effective for use in protective clothing and desalination. This work could inspire innovative design of ecofriendly nanofibrous materials for high-performance filtration and separation.