Synthesis of Zirconia Aerogels by Ambient Pressure Drying with Propylene Oxide Addition

ZrO2 aerogels were successfully synthesized by the sol-gel process and ambient pressure drying using ZrO(NO3)(2)center dot 5H(2)O as a precursor, 1,2-propylene oxide (PO) as a gelation agent, and formamide (FA) as a drying control chemical additive (DCCA). The prepared zirconia aerogel samples were characterized using differential thermal analysis (DTA), scanning electron microscopy (SEM), and nitrogen adsorption/desorption analysis. The results showed that the zirconia aerogels prepared by the propylene oxide addition method had a nanoscale porous network structure, as well as supercritical dried ones, with a low bulk density (202.08 kg.m(-3)) and a high surface area (645.0 m(2).g(-1)). Propylene oxide can induce gelation through its nucleophilic property and its irreversible ring-opening reaction, and thus the sol-gel process and the state of gel can be controlled.