溶胶组成对氧化铝纤维微观结构及性质的影响

Impacts of Sol Composition on Microstructure and Properties of Alumina Fibers

以氯化铝和铝粉为铝源,水为溶剂,乙醇为辅助溶剂,采用溶胶-凝胶结合静电纺丝方法,制备了柔性γ和α氧化铝纤维,研究了溶胶中铝单体和Al_(13)组成情况对氧化铝纤维微观结构、物相转变和隔热性能的影响。溶胶中Al_(13)含量较多能推迟纤维的物相转变,使γ-Al_2O_3纤维的气孔和组成颗粒增大,降低γ-Al_2O_3纤维的比表面积,降低γ-Al_2O_3和α-Al_2O_3纤维的导热系数。S4组γ-Al_2O_3和α-Al_2O_3纤维的导热系数仅为0.08087和0.1251 W/m·k。研究表明,溶胶中较高的Al_(13)含量有利于提高纤维材料的隔热性能。

Using aluminum chloride and aluminum as raw materials, pure water as solvent, ethanol as aid solvent, alumina sols containing different proportions of alumina monomer and Al 13 were prepared. Gel fibers were prepared by electrospinning, and flexible flocculence γ-Al 2O 3 and α-Al 2O 3 fibers were fabricated. The impacts of sol composition on the microstructure of fibers, phase transformation and insulation performance were investigated. Al 13 can delay the phase transformation of the fibers, more content of Al 13 in sol can enlarge the size of pore and grain of γ-Al 2O 3 fibers, and reduce specific surface area as well as the thermal conductivity of alumina fibers. The thermal conductivity of γ and α alumina fibers prepared by S4 was only 0.08087 and 0.1251 W/m?k, indicating that high content of Al 13 was good for improving the thermal insulation properties of the fibers.