Scalable Super-hydrophobic Polyurethane/Fluorinated Polyurethane/SiO2 Nanofibrous Membranes for Waterproof and Breathable Application

Superhydrophobic fibrous materials are highly desirable for improving wearing comfort and protection however, constructing durable superhydrophobic fabrics with excellent moisture permeability and high resistance to water penetration remains a great challenge. Therefore, we present an efficient and facile approach to construct super-hydrophobic polyurethane/fluorinated polyurethane/SiO 2 (PU/FPU/SiO 2 ) nanofibrous membranes via the incorporation of electrospinning and hot-pressing. SiO 2 nanoparticles are incorporated into the PU/FPU nanofibers, creating a multi-level micro/nano-scale roughness. Specifically, the aggregation of composite nanofibers contributes to micro-roughness, while the addition of SiO 2 nanoparticles gives rise to nano-roughness. FPU has an extremely low surface energy. We intend to add FPU to boost the hydrophobicity of the membranes, so as to obtain super-hydrophobic characteristics. Moreover, we comprehensively study the effect of the SiO 2 nanoparticles concentration on the hydrophobicity of nanofibrous membranes and also discover the influence of heat treatment temperature on the porous structure of nanofibrous membranes. According to our design, the final membranes are anticipated to show a combination of an outstanding super-hydrophobic surface (water contact angle of 152°), good waterproof and breathable properties (high water vapor transmission rate of 7.9 kg m −1  d −1 and excellent hydrostatic pressure of 59 kPa). This indicates that PU/FPU/SiO 2 nanofibrous membranes have great potential for use in the next generation of protective fabrics. Graphical