Fabrication of electrospun Al2O3 fibers with CaO–SiO2 additive

Abstract Alumina fibers were fabricated by the sol–gel method combined with an electrospinning process using aluminum chloride hexahydrate (AlCl 3 ·6H 2 O) and aluminum powder as raw materials in water solvent. Calcium oxide–silica (CaO–SiO 2 ) was applied as two-component additive to retard the phase transformation of alumina and control the size of the grains during sintering. With the addition of the CaO–SiO 2 in the system, the size of the particles that composed the fibers calcined at 1300 °C significantly decreased compared to that without additive, which might be due to the formation of θ-alumina in the samples. In addition, the fiber had low thermal conductivity and good flexibility, which favored its application in insulation.