Nano-Silica Bubbled Structure Based Durable and Flexible Superhydrophobic Electrospun Nanofibrous Membrane for Extensive Functional Applications

Nanoscale surface roughness has conventionally been induced by using complicated approaches; however, the homogeneity of superhydrophobic surface and hazardous pollutants continue to have existing challenges that require a solution. As a prospective solution, a novel bubbled-structured silica nanoparticle (SiO2) decorated electrospun polyurethane (PU) nanofibrous membrane (SiO2@PU-NFs) was prepared through a synchronized electrospinning and electrospraying process. The SiO2@PU-NFs nanofibrous membrane exhibited a nanoscale hierarchical surface roughness, attributed to excellent superhydrophobicity. The SiO2@PU-NFs membrane had an optimized fiber diameter of 394 +/- 105 nm and was fabricated with a 25 kV applied voltage, 18% PU concentration, 20 cm spinning distance, and 6% SiO2 nanoparticles. The resulting membrane exhibited a water contact angle of 155.23 degrees. Moreover, the developed membrane attributed excellent mechanical properties (14.22 MPa tensile modulus, 134.5% elongation, and 57.12 kPa hydrostatic pressure). The composite nanofibrous membrane also offered good breathability characteristics (with an air permeability of 70.63 mm/s and a water vapor permeability of 4167 g/m(2)/day). In addition, the proposed composite nanofibrous membrane showed a significant water/oil separation efficiency of 99.98, 99.97, and 99.98% against the water/xylene, water/n-hexane, and water/toluene mixers. When exposed to severe mechanical stresses and chemicals, the composite nanofibrous membrane sustained its superhydrophobic quality (WCA greater than 155.23 degrees) up to 50 abrasion, bending, and stretching cycles. Consequently, this composite structure could be a good alternative for various functional applications.