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.
参考文献
| [1] | 倪星元,周斌,吴广明,沈军,王珏.溶胶-凝胶法制备惯性约束聚变靶材料研究[J].原子能科学技术,2002(04):301-304. |
| [2] | Chen L W;Gan L H;Hou X H .Preparation and progress of silica aerogels by non-supercritical drying method[J].Journal of Physic and Chemistry,2003,99(1):819-823. |
| [3] | 毕于铁,任洪波,陈擘威,陈庚,张林.氧化镍气凝胶的制备与表征研究[J].功能材料,2012(11):1361-1363. |
| [4] | Wang J;Zhou B;Wu W D et al.Process on the research of silica aerogels[J].Journal of Functional Materials,1995,26(1):15-19. |
| [5] | Qin G T;Li W C;Guo S C .Process on the research of silica aerogels[J].Journal of Functional Materials,2000,31(1):26-32. |
| [6] | Norimatsu T;Chen C M;Nakajima K et al.Cryogenic targets and related technologies at ILE osaka university[J].J Vac Technol,1994,A12(4):1293. |
| [7] | Zheng C X;Jing D W;Guo L J.Fe-doped Ta2 O5 cata-lyst’s performance for photocatalytic production of hydro-gen[A].上海,2005 |
| [8] | Shen J;Wang J;Wu X .Aerogels-a type of structure controllable new functional materials[J].Materials Sci-ence and Engineering,1994,12(3):1-5. |
| [9] | 任洪波,王鲜,张林,张勇,毕于铁,万小波.基于TaCl5的Ta2O5气凝胶制备工艺[J].强激光与粒子束,2008(01):87-90. |
| [10] | 杨静,任洪波,毕于铁,罗炫.金属醇盐法制备Ta2O5气凝胶[J].强激光与粒子束,2011(07):1885-1888. |
| [11] | Zhou X C;Wei K .Preparation of silica aerogels under ambient pressure by two-step method[J].China Ceram-ic Industry,2005,2(12):19-21. |
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