Flexible carbonaceous silica nanofibers with superior toughness and strength for oil-in-water emulsions separation

Abstract

Ceramic materials have a host of applications from thermal insulation, catalysis, and laser lighting to high temperature filtration due to its unique features, such as high temperature resistance, corrosion proof, and low thermal conductivity, etc. However, current ceramic materials are usually brittle with small toughness and poor tolerance to vibration and buckling, which have restricted its applications in various areas. Herein, the flexible carbonaceous silica (CS) nanofiber membranes with superior toughness and strength were facile fabricated via the sol–gel method and electrospinning technique. The in-situ generated carbonaceous materials and force-induced lamellar structure played important roles in enhancement of mechanical properties and regularity of wettability. The unique features of CS nanofibers favored the membranes with robust mechanical properties with the tensile strength of 6.8 MPa and breaking elongation rate of 78 %, which is much higher than that of conventional ceramic fibers. The resultant membranes exhibited outstanding separation performance towards oil-in-water emulsions with high separation efficiency of ∼ 98.4 %, large permeation flux of 7345.4 L m-2h−1, good reusability within 10 cycles, and long-term usability. In addition, the membranes also exhibited good separation performance towards emulsion in hash environment. In addition, the flexible CS nanofiber membrane based spoon was used to vividly separate oil/water mixture and emulsions, which is promising for large-scale remediation of wastewater under extreme conditions.