Super-hydrophobic self-cleaning bead-like SiO2@PTFE nanofiber membranes for waterproof-breathable applications

Superhydrophobic waterproof-breathable membranes, which possess a huge superiority in multifunctional applications including self-cleaning, anti-icing, anticorrosion and protective clothing, have aroused considerable attention owing to their excellent performance. Herein, the robust superhydrophobic microporous fibrous membranes were efficiently prepared via a facile and environmental-friendly electro-blown spinning (EBS) technique followed by calcination. Compared with hydrophobic pure PTFE fibrous membranes, the bead-like SiO2@PTFE nanofiber membranes (BLNFMs) exhibited superhydrophobic surface with the advancing water angle (theta(adv)) and the water contact angle (WCA) up to 161 degrees and 155 degrees, respectively. The SiO2 nanoparticles were introduced as fillers which can alter the pore structure and form the multilevel rough surface. The BLNFMs could maintain superhydrophobic surface even after abrasion for 30 times or exposing to a strong corrosive solution with PH from 0 to 12 for 24 h. Besides, the BLNFMs were endowed with the modest vapor permeability (9.7 kg.m (2).d (1)) and air permeability (7.2 mm.s (1)) when the concentration of SiO2 nanoparticles reached to 7.3 wt%. In addition, a potential relationship among hadv, maximum pore size (d(max)) and breathability (effective breathing area) was proposed in order to design the waterproof-breathable membranes with excellent properties. Furthermore, the superhydrophobic membranes with durable self-cleaning property provided the advantages of potential applications in the fields of membrane distillation, versatile protective clothing, etc. (C) 2018 Elsevier B.V. All rights reserved.