Alumina Nanofibers Prepared by Coupling Sol-Gel with Electrospinning Method

The flexible alumina nanofibers were prepared by coupling sol-gel with electrospinning method. The as-spun composite nanofibers were obtained by electrospinning a mixture of the pseudo-boehmite sol and polyvinyl pyrrolidone (PVP) ethanol solution. SiO2 was added in the pseudo-boehmite sol to retard the phase transformation of the fired fibers. Upon firing and sintering under carefully pre-selected heating schedule, the crystalline alumina nanofibers were obtained. Tools such as TG-DSC, X-ray diffraction, transmission electron microscope together with scanning electron microscope were employed to characterize the evolution of the ceramic phase and morphological features of the pseudo-boehmite sol and composite fibers before and after fired. The experimental results show that the flexible fibers with uniform diameter of about 400-700 nm as well as no defects such as cracks or holes even calcined at 1300 °C can be prepared by marriage of electrospinning with sol-gel processing.