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

Abstract

ZrO_2 aerogels were successfully synthesized by the sol-gel process and ambient pressure drying using ZrO(NO_3)_2·5H_2O 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.