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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Ta2O5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Ta2O5气凝胶的比表面约为493m2/g,NLDFT理论得出孔径主要分布在2~8nm之间,比一步酸催化制备的Ta2O5气凝胶的比表面(400m2/g)高、孔径分布(2~20nm)窄;SEM测试结果表明酸-碱两步催化制备的Ta2O5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Ta2O5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。
Tantalum oxide as a precursor, hydrochloric acid / ammonia as a catalyst for the preparation of massive tantalum oxide airgel. Ta2O5 airgel prepared by two-step acid-base catalysis has the advantages of fast gel time, low density, high strength, easy to crack, small shrinkage and translucence. The prepared aerogels were characterized by SEM, BET and the like. BET specific surface area of about 493m2 / g Ta2O5 airgel prepared by acid-base two-step catalysis, NLDFT theory pore size distribution mainly between 2 ~ 8nm, one-step acid-catalyzed preparation of Ta2O5 airgel ratio (400m2 / g) and narrow pore size distribution (2 ~ 20nm). The SEM results showed that the Ta2O5 airgel prepared by acid-base two-step catalysis was randomly deposited by nano-particles. Compared with one-step acid-catalyzed Ta2O5 gas Compared with the gel nanoparticles with small size, narrow pore size distribution and other advantages. The reaction mechanism in the process of hydrochloric acid / ammonia preparation was also explored.