Effects of the polyvinyl alcohol (PVA) on the synthesis of alumina fibers through electrospinning technique

Abstract

Ceramic fiber products especially alumina has good properties such as high modulus and strength that were resistant toward the attacks of molten metals and nonoxide materials up to 1000°C and also have low thermal conductivity and high melting point. Alumina is a well-known structural material among functional ceramics in the area of catalysts, microelectronics and optic, both in pure or doped form as well as in combination with others. In this work, alumina fiber was synthesized by sol-gel electrospinning technique (e-spinning). The sol was prepared by mixing aluminum nitrate nonahydrate (ALN) and aluminum isopropoxide at 3 molar ratios. The precursor sol was stirred vigorously for 24 hours until ALP completely dissolved. After stirring, the precursor sol with PVA and without PVA was evaporating to obtain the suitable viscosity to spin. The rheology and viscosity were checked by viscometer. At the appropriate viscosity, the sol was spin into fibers using electrospinning machine. The green fibers were then dried at room temperature then calcined at 1200°C. The fibers produced were characterized using X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscope (FESEM). The XRD analysis had shown the -alumina was formed at 1200 °C and SEM micrograph shows the formation of fibers with PVA addition.