以工业硅溶胶作为硅源,分别添加甲酰胺(FA)、二甲基甲酰胺(DMF)(其与SiO2的物质的量比分别为0∶1、0.1∶1、0.25∶1、0.5∶1、0.75∶1、1∶1),经溶胶-凝胶过程,结合CO2超临界干燥工艺制备了SiO2气凝胶,研究了FA、DMF对体系凝胶时间、SiO2气凝胶密度以及比表面积的影响.结果表明:FA、DMF的加入有利于体系获得完整、无开裂的气凝胶样品,且随着FA、DMF添加量的增大,由于其延缓羟基的缩聚反应以及和乙醇的亲和作用,使得体系的凝胶时间越来越长,但气凝胶密度和比表面积并无显著变化,同时FA、DMF对体系影响的差别不大.所制备的气凝胶样品具有纳米多孔结构,比表面积为220～235 m2·g-1,密度为180～198 kg·m-3.
参考文献
| [1] | Kistler S S .Coherent expanded-aerogels[J].Journal of Physical Chemistry,1932,36(01):52-64. |
| [2] | Pradip B. Sarawade;Jong-Kil Kim;Askwar Hilonga .Production of low-density sodium silicate-based hydrophobic silica aerogel beads by a novel fast gelation process and ambient pressure drying process[J].Solid state sciences,2010(5):911-918. |
| [3] | Shlyakhtina A;Oh YJ .Transparent SiO2 aerogels prepared by ambient pressure drying with ternary azeotropes as components of pore fluid[J].Journal of Non-Crystalline Solids: A Journal Devoted to Oxide, Halide, Chalcogenide and Metallic Glasses, Amorphous Semiconductors, Non-Crystalline Films, Glass-Ceramics and Glassy Composites,2008(15/16):1633-1642. |
| [4] | Lee S;Cha Y C;Hwang H J et al.The effect of pH on the physicoehemical properties of silica aerogels prepared by an ambient pressure drying method[J].Materials Letters,2007,61(14-15):3130-3133. |
| [5] | Kocon L.;Phalippou J.;Despetis F. .Ultralow density silica aerogels by alcohol supercritical drying[J].Journal of Non-Crystalline Solids: A Journal Devoted to Oxide, Halide, Chalcogenide and Metallic Glasses, Amorphous Semiconductors, Non-Crystalline Films, Glass-Ceramics and Glassy Composites,1998(1):96-100. |
| [6] | Deng ZS.;Wu AM.;Shen J.;Zhou B.;Wang J. .High strength SiO2 aerogel insulation[J].Journal of Non-Crystalline Solids: A Journal Devoted to Oxide, Halide, Chalcogenide and Metallic Glasses, Amorphous Semiconductors, Non-Crystalline Films, Glass-Ceramics and Glassy Composites,1998(1):101-104. |
| [7] | Chan J B;Jonas J .Effect of various amide additives on the TMOS sol-gel process[J].Journal of Non-Crystalline Solids,1990,126(1-2):79-86. |
| [8] | Uchida N;Ishiyama N;Kato Z et al.Chemical effects of DCCA to the sol-gel reaction process[J].Journal of Materials Science,1994,29(19):5188-5192. |
| [9] | Venkateswara R A;Sakhare H M;Tamhankar A K et al.Influence of N,N-Dimethylformamide additive on the physical properties of citric acid catalyzed TEOS silica aerogels[J].Materials Chemistry and Physics,1999,60(03):268-273. |
| [10] | 杨丽静,田辉平,龙军,严加松.碱性硅溶胶稳定性的研究[J].石油炼制与化工,2010(06):12-16. |
| [11] | 曾新安,杨星.不同浓度下乙醇-水溶液的缔合状态[J].华南理工大学学报（自然科学版）,2010(12):120-123. |
| [12] | 王宬舒,谢超,王涛.添加剂对气凝胶孔径分布的影响[J].过程工程学报,2010(02):355-360. |
| [13] | 甘礼华,张宇星,陈龙武,葛奇.干燥控制化学添加剂在制备硅气凝胶中的应用[J].同济大学学报(自然科学版),2003(09):1131-1134. |
| [14] | 王冬冬,丁书强,王自强,王泽华,陈伟.常压干燥法制备SiO2气凝胶粉体[J].耐火材料,2011(02):96-99. |
| [15] | Boonstra A H;Bernards T N M;Smits J J T .The effect of formamide on silica sol-gel processes[J].Journal of Non-Crystalline Solids,1989,109(2-3):141-152. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%