CAJ | 학술논문

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。
이을순단위전구체,염산/안수위최화제제비출괴상양화단기응효。량보산-감최화법제비적Ta2 O 5기응효구유응효시간쾌、밀도저、강도고、불역개렬、수축소화반투명등우점。대제비적기응효용SEM、BET등수단진행표정。BET 법측득산-감량보최화제비 Ta2 O5기응효적비표면약위493 m2/g, NLDFT이론득출공경주요분포재2~8 nm 지간,비일보산최화제비적 Ta2 O5기응효적비표면(400 m2/g)고、공경분포(2~20 nm)착；SEM측시결과표명산-감량보최화제비적 Ta2 O 5기응효시유납미과립수궤퇴적기래적,여일보산최화제비적 Ta2 O 5기응효상비구유납미과립척촌소、공경분포착등우점。병대염산/안수제비과정중적반응궤리진행료초보탐색。
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.