Silica nanofibrous membranes with robust flexibility and thermal stability for high-efficiency fine particulate filtration

Novel silica nanofibrous (SNF) membranes with remarkable flexibility and thermal stability were prepared as high-performance filtration media by a facile combination of electrospinning and sol–gel methods. The flexibility and tensile strength of the SNF membranes can be finely controlled by regulating the calcination temperature and precursor fiber composition. A plausible correlation between the flexibility and crystalline phase of silica was proposed, and the tensile fracture process of the SNF membranes was discussed. Additionally, the mesoporous effect of the SNF membranes was also investigated from the nitrogen physisorption isotherms. Furthermore, the SNF membranes with excellent flexibility (0.0156 gf cm), tensile strength (5.5 MPa), and thermal stability (up to 1000 °C) showed a high filtration efficiency (99.99%) and a low pressure drop (163 Pa) for 300–500 nm sodium chloride aerosols, suggesting a promising candidate for high-temperature filtration applications. This also provides new insight into the design and development of flexible inorganic nanomaterials for various applications.