Fabrication of boehmite nanofiber aerogels by a phosphate gelation process for optical applications

A transparent wet gel was obtained in a few minutes at room temperature by adding an aqueous phosphoric acid solution of appropriate concentration to boehmite nanofiber sol. After aging and supercritical carbon dioxide drying, low bulk density aerogels with visible light transmittance over 90% 10 mm thickness were obtained. These exhibited high Young’s modulus transmittance, while having the same as samples conventional gelation process using base. The optical aerogel hardly lost even humidity because phosphorylation skeletal surface reduced percentage hydroxyl groups. three-dimensional imaging inspection exterior interior carried out. various developments reported this paper make ultralow (<0.01 g cm−3) transmission more promising for applications physical field. Graphical abstract