The structure of spinnable solution of triethylaluminium and ethylsilicate-40 and calcination process of drawn alumina gel fiber were investigated. In spinnable solution there were no Al-O-Si bonds between polyaluminoxane, whose average polymerization degree was about 24, and ethylsilicate-40. The Al-O-Al and Al-O-Si bonds and five-coordinated aluminium atoms were formed during calcination process until γ-alumina was crystallized in the fiber around 960°C, due to elimination of alcohol and water. With the crystallization of γ-alumina, the amorphous silica was segregated, and located between alumina crystals.
