Fabrication and characterization of electrospun mullite nanofibers

Continuous mullite (3Al2O3·2SiO2) nanofibers were fabricated by a sol–gel electrospinning technique. The detailed crystallization development and micromorphological evolution of both the as-electrospun nanofibers and the sintered mullite nanofibers were investigated. Results indicated that the spinnability and micromorphological evolution of mullite nanofibers are largely dependent on the viscosity η of the mullite sol, which can be adjusted by polyvinylprrolidone (PVP) content. Mullite nanofibers with common cylindrical morphology and diameters ranging from 400 nm to 800 nm could be obtained easily and rapidly when PVP content is ranged from 5 wt.% to 8 wt.%. High purity polycrystalline mullite nanofibers with diameters of about 200 nm were obtained after sintering at 1200 °C for 2 h. All sintered nanofibers consisted of single crystalline grains with size of approximately 100 nm.