Abstract: The optimization of the microstructure and mechanical properties of SiO₂ nanofibers was achieved by adjusting the composition of the electrospining method and the heat treatment process. In this paper, tetraethyl orthosilicate (TEOS) was used as raw material, polyvinylpyrrolidone (PVP) was used as spinning aid, and SiO₂ nano-membrane was prepared by electrospinning method combined with heat treatment process. The effects of polymer concentration and calcination rate on the microscopic morphology and mechanical properties of fiber membranes were studied. Using means of thermogravimetric and differential thermal analysis, X-ray diffractometer, fourier infrared spectrometer, scanning electron microscope and tensile testing machine, the fiber membrane was microscopically analyzed and tested. The results show that with the increase of PVP concentration, the morphology of the product develops from dice-shaped microspheres to continuous fibers, and the mechanical properties are improved accordingly. When the mass fraction of PVP is 25%, the fiber membrane has the best tensile strength, which is 3.25 MPa. With the increase of the heating rate, after the SiO₂/PVP continuous fiber membrane is calcined at 800 ℃, the residual thermal stress inside the product increases, the fiber continuity decreases, and the strength decreases. This research provides a theoretical basis for the functional application of SiO₂ nanofibers.

Key words: SiO₂, nanofiber, electrostatic spinning, polymer concentration, calcination rate, tensile strength