Research progress of ultrafine alumina fiber prepared by sol-gel method: A review

As a widely used high-performance inorganic fiber material, preparation and application of ultrafine alumina fibers have attracted much attention in last decades. Therein, preparation of ultrafine alumina fibers via sol gel method has the characteristics of simple synthetic procedure, easy regulation of fiber components and well design of fiber structures, etc., which have been developed rapidly in recent years. In this paper, the research progress of ultrafine alumina fibers prepared via sol-gel method is comprehensive reviewed, which mainly focus on the aspects of fiber forming process and the fiber structure construction during sol-gel method. According to the different fiber formation processes during sol-gel method, the centrifugal spinning, electrospinning and electro-blown spinning for preparation of ultrafine alumina fiber are demonstrated respectively. The effects of different fiber forming process on the structure and properties of ultrafine alumina fiber are compared and analyzed. Particularly, the sol-gel ultrafine alumina fibers constructed with porous, hollow and other profiled structures are special described. Furthermore, the sol-gel ultrafine alumina fibers application in the environment protection, energy storage fields and refractory and thermal insulation fields are also summarized. Novel ultrafine alumina fiber based materials emerging in recent years, such as alumina based MOF and threedimensional alumina aerogels have been concerned. Finally, the future development of sol-gel ultrafine alumina fiber is prospected, which provides some reference value for the further study of ultrafine alumina fiber.