水对常压干燥制备块状TiO_2气凝胶显微结构的影响

Effect of H_2O on microstructure of TiO_2 aerogel with block size prepared by ambient pressure drying process

以钛酸丁酯(TTIP)为前驱体、乙酸为催化剂、甲酰胺为干燥控制化学添加剂,通过控制原料中TTIP与H2O的摩尔比以及老化液中H2O与乙醇(EtOH)的摩尔比,并结合常压干燥工艺,制备块状TiO2气凝胶。采用XRD、BET、SEM和FT-IR等对样品进行表征。结果表明,当原料中TTIP与H2O的摩尔比为1:4、老化液中H2O与EtOH的摩尔比为5:2时,TiO2气凝胶具有最小表观密度(0.15 g/cm3)、最大比表面积(573.4 m2/g)、孔径分布集中、块体体积约为16.0 cm3。

TiO 2 aerogels with block size were prepared by ambient pressure drying process via sol-gel technology using tetrabutyl orthotitanate （TTIP） as precursor, acetic acid as catalyst, formamide as drying control chemical additive. The influencing factors of the molar ratio of TTIP to H 2 O, the molar ratio of H 2 O to EtOH in the aging liquid were analyzed. The structures of the samples were characterized by XRD, BET, SEM and FT-IR. The results indicate that when molar ratios of TTIP to H 2 O and H 2 O to EtOH are 1：4 and 5：2, respectively, the prepared TiO 2 aerogels have the best performance of the least bulk density of 0.15 g/cm3, the largest specific surface area of 573.4 m2/g, and the block volume of about 16.0 cm3.