材料工程与机械制造

溶胶共凝法制备准连续密度梯度SiO2气凝胶

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  • 同济大学 上海市特殊人工微结构材料与技术重点实验室, 上海 200092
归佳寅(1986- ) 男,硕士。主要研究方向:气凝胶类材料。 Tel: 021-65982762 E-mail: guijy@126.com 周斌(1970- ) 男,博士,教授,博士生导师。主要研究方向:纳米材料。 Tel: 021-65980228 E-mail: zhoubin863@tongji.edu.cn

收稿日期: 2010-07-20

  修回日期: 2010-10-18

  网络出版日期: 2011-05-19

基金资助

国家自然科学基金青年基金(50802064); 高等学校博士学科点专项科研基金(20090072110047);上海市科委纳米专项(0952nm00900)

Fabrication of Graded Density SiO2 Aerogel via Sol-Co-Gelation Techniques

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  • Shanghai Key Laboratory of Special Microstructure Materials and Technology, Tongji University, Shanghai 200092, China

Received date: 2010-07-20

  Revised date: 2010-10-18

  Online published: 2011-05-19

摘要

针对气凝胶在航空航天领域的应用需求,为了进一步拓展单一密度气凝胶的应用范围,对密度梯度SiO2气凝胶的制备进行了研究。采用自建密度梯度制备成型装置,以正硅酸乙酯为有机硅源,经溶胶共凝工艺,结合CO2超临界干燥技术,获得密度范围在60~160 mg/cm3的准连续密度梯度SiO2气凝胶。采用光学显微镜、扫描电子显微镜、X射线相衬成像等手段对制备获得的SiO2气凝胶进行测试表征。通过与逐层凝胶法制备的密度渐变SiO2气凝胶进行对比发现,溶胶共凝工艺消除了层间界面处所产生的致密层和密度突变,有利于相邻两层间的互扩散,使密度变化更趋于连续。采用该法制备的密度梯度气凝胶拓展了常规气凝胶的应用范围,在声阻抗匹配和空间粒子捕获等领域有潜在的应用前景。

本文引用格式

归佳寅, 周斌, 钟艳红, 杜艾, 沈军 . 溶胶共凝法制备准连续密度梯度SiO2气凝胶[J]. 航空学报, 2011 , 32(5) : 941 -947 . DOI: CNKI:11-1929/V.20101213.1757.012

Abstract

For the application requirement in aerospace and further expanding the application field of aerogel, the fabrication of gradient density aerogel SiO2 has been researched in this paper. By a self-built device, a continuously graded silica aerogel is fabricated via special sol-co-gelation techniques, with tetraethoxysilane (TEOS) as the organic precursor and by a supercritical drying process. Its density ranges from 60 mg/cm3 to 160 mg/cm3. Scan electron microscope, X-ray phase contrast method and optical microscopy are used to characterize the graded density silica aerogel prepared. Compared with the graded density silica aerogel produced by layer-by-layer gelation techniques, the sol-co-gelation techniques smooth out density mutation and increase the interdiffusion between adjacent layers, which makes density change tend to be more continuous. The gradient density aerogel fabricated by such a method expands greatly the application of conditional aerogel. It can potentially be used in many fields such as acoustic impedance matching and interstellar particles collection.

参考文献

[1] Zolensky M E, Zega T J, Yano H, et al. Mineralogy and petrology of comet 81P/Wild 2 nucleussamples[J]. Science, 2006, 314 (5806): 1735-1739.

[2] Sandford S A, Aleon J, Alexander C M, et al. Organics captured from comet 81P Wild 2 by the Stardust spacecraft[J]. Science, 2006, 314(5806): 1720-1724.

[3] Tsou P. Silica aerogel captures cosmic dust intact[J]. Journal of Non-Crystalline Solids, 1995, 186: 415-427.

[4] Tsou P, Brownlee D E, Sandford S A, et al. Wild 2 and interstellar sample collection and earth return[J]. Journal of Geophysical Research, 2003, 108(E10):8113-8133.

[5] Brownlee D E, Tsou P, Atkins K L, et al. Stardust: finessing expensive cemetery sample returns[J]. Acta Astronautica, 1996, 39 (1-4): 51-60.

[6] Jones S M. A method for producing gradient density aerogel[J]. Journal of Sol-Gel Science and Technology, 2007, 44(3): 255-258.

[7] Jones S M. Aerogel space exploration applications[J]. Journal of Sol-Gel Science and Technology, 2006, 40(2-3):351-357.

[8] Jones S M. Gradient composition sol-gel materials//Proceedings of SPIE. 2000, 3943: 260-269.

[9] Hrubesh L W, Alviso C T. Optical characterization of silica aerogel[J]. Materials Research Society, 1988, 121: 703-709.

[10] Gerlach R, Kraus O, Fricke J, et al. Modified SiO2 aerogels a acoustic impedance matching layers in ultrasonic devices[J]. Journal of Non-Crystalline Solids, 1992,145: 227-232.

[11] Bellunato T, Calvi M, Matteuzzi C, et al. Refractive index of silica aerogel: uniformity and dispersion law[J]. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2008,595(1): 183-186.

[12] Hüsing N, Schubert U. Aerogels—airy materials: chemistry, structure, and properties[J]. Angewandte Chemie International Edition, 1998, 37(1-2): 22-45.

[13] Burchell M J, Fairey S A J, Foster N J, et al. Hypervelocity capture of particles in aerogel: dependence on aerogel properties[J]. Planetary and Space Science, 2009,57(1): 58-70.

[14] Jones S M. Aerogel: space exploration applications[J]. Journal of Sol-Gel Science and Technology, 2006,40(2-3): 351-357.

[15] 禹爱民,李政,章迪,等. 微焦点X射线源类同轴相衬成像[J]. 高能物理与核物理,2006,30(11): 1119-1122. Yu Aimin,Li Zheng,Zhang Di,et al. In-line phase contrast imaging using a micro-focus X-ray source[J]. High Energy Physics and Nuclear Physics,2006,30(11): 1119-1122. (in Chinese)
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