酸-碱两步催化对氧化钽气凝胶形貌及性能的影响  

Preparation of tantalum oxide aerogels by two-stepacid and basic catalyst method

作　　者：任达华[1,2] 杨睿戆[1] 罗炫[1] 方瑜[1] 黄传群[1] 张庆军[1] 陈姝帆[1] 程新路[2] 吴卫东[1,2] 

机构地区：[1]中国工程物理研究院激光聚变研究中心等离子体重点实验室,四川绵阳621900 [2]四川大学原子与分子物理研究所,四川成都610065

出　　处：《功能材料》2013年第24期3647-3650,共4页Journal of Functional Materials

基　　金：中国工程物理研究院发展基金资助项目(2010B0302047)

摘　　要：以乙醇钽为前驱体,盐酸/氨水为催化剂制备出块状氧化钽气凝胶。两步酸-碱催化法制备的Ta2 O 5气凝胶具有凝胶时间快、密度低、强度高、不易开裂、收缩小和半透明等优点。对制备的气凝胶用SEM、BET等手段进行表征。BET 法测得酸-碱两步催化制备 Ta2 O5气凝胶的比表面约为493 m2/g, NLDFT理论得出孔径主要分布在2~8 nm 之间,比一步酸催化制备的 Ta2 O5气凝胶的比表面（400 m2/g）高、孔径分布（2~20 nm）窄；SEM测试结果表明酸-碱两步催化制备的 Ta2 O 5气凝胶是由纳米颗粒随机堆积起来的,与一步酸催化制备的 Ta2 O 5气凝胶相比具有纳米颗粒尺寸小、孔径分布窄等优点。并对盐酸/氨水制备过程中的反应机理进行了初步探索。Ta2 O5 aerogels were prepared by sol-gel process and supercritical drying technique.The sol gel process mainly consisted of hydrolysis and condensation reaction was controlled by two-step catalyst.Ta2 O5 aerogels prepared with two-step acid and basic catalyst method show rigidity,translucence and low constriction in comparision with one-step acid catalyst method.The resulting aerogels were characterized by means of BET and SEM.It was found that Ta2 O5 aerogels have a higher inner surface of 493 m2/g and more porous structure with two-step acid and basic catalyst method than one-step acid catalyst method.According to the non-local density functional theory（NLDFT）,the pore width distribution was from 2 to 8 nm with two-step acid and bas-ic catalyst method rather than from 2 to 20 nm with one-step acid catalyst method.SEM shows that a mount of nano-particles randomly constructed consist of typical amorphous and mesoporous aerogels.The catalysis mech-anisms of acid and basic for sol gel process are discussed initially.

关 键 词：Ta2 O5气凝胶 酸-碱两步催化法 一步酸催化法 CO2超临界干燥技术 

分 类 号：TL69[核科学技术—核技术及应用]