期刊文献+

A study of morphological properties of SiO_2 aerogels obtained at different temperatures 被引量:5

A study of morphological properties of SiO_2 aerogels obtained at different temperatures
原文传递
导出
摘要 In this paper, temperature dependence of nanoporous framework evolution process and variety of pore properties(pore volume, specific surface area(BET), and pore size) of SiO_2 aerogels were characterized by FTIR, XPS, XRD, SEM, TEM, BET, BJH, etc. Results show that SiO_2 aerogels treated at different temperatures all possess amorphous structure. With the increase of treated temperatures, BET values of SiO_2 aerogels increase initially and then decrease, and it reaches the maximum value of 882.81 m^2/g when treated at 600 ℃ for 2 h due to the addition of the nanopores and shrinkage skeleton of SiO_2 aerogels. Higher temperatures may result in a framework transformation and particle growth; both factors could reduce the BET values of the aerogels. Nanoporous skeleton of SiO_2 aerogels at room temperatures is composed of tetrahedron with a pore size of about 22.28 nm. Higher treated temperatures result in an increase of octahedron amount in nanoporous framework and a decrease of pore size. When treated at 1000 ℃, an approximate dense SiO_2 bulk via the framework collapse and particle growth is obtained. These varieties are derived from the formed extra bonds of Si–O–Si, higher local stress, and liquid phase between particles during heat treatment process. In this paper, temperature dependence of nanoporous framework evolution process and variety of pore properties(pore volume, specific surface area(BET), and pore size) of SiO_2 aerogels were characterized by FTIR, XPS, XRD, SEM, TEM, BET, BJH, etc. Results show that SiO_2 aerogels treated at different temperatures all possess amorphous structure. With the increase of treated temperatures, BET values of SiO_2 aerogels increase initially and then decrease, and it reaches the maximum value of 882.81 m^2/g when treated at 600 ℃ for 2 h due to the addition of the nanopores and shrinkage skeleton of SiO_2 aerogels. Higher temperatures may result in a framework transformation and particle growth; both factors could reduce the BET values of the aerogels. Nanoporous skeleton of SiO_2 aerogels at room temperatures is composed of tetrahedron with a pore size of about 22.28 nm. Higher treated temperatures result in an increase of octahedron amount in nanoporous framework and a decrease of pore size. When treated at 1000 ℃, an approximate dense SiO_2 bulk via the framework collapse and particle growth is obtained. These varieties are derived from the formed extra bonds of Si–O–Si, higher local stress, and liquid phase between particles during heat treatment process.
出处 《Journal of Advanced Ceramics》 SCIE CSCD 2018年第4期307-316,共10页 先进陶瓷(英文)
关键词 SILICA AEROGEL temperature dependence NANOPOROUS framework evolution PORE properties silica aerogel temperature dependence nanoporous framework evolution pore properties
  • 相关文献

参考文献4

二级参考文献37

  • 1林高用,张栋,卢斌.非超临界干燥法制备块状SiO_2气凝胶[J].中南大学学报(自然科学版),2006,37(6):1117-1121. 被引量:19
  • 2Fei SHI,Lijiu WANG,Jingxiao LIU,Miao ZENG.Effect of Heat Treatment on Silica Aerogels Prepared via Ambient Drying[J].Journal of Materials Science & Technology,2007,23(3):402-406. 被引量:7
  • 3HEGDE N D, VENKATESWARA R A. Organic modification of TEOS based silica aerogels using hexadecyltrimethoxysilane as a hydrophobic reagent [J]. Applied Surface Science, 2006, 253 (3): 1566-1572.
  • 4PRAKASH S S, JEFFREY B C, HURD A J. Silica aerogel films at ambient pressure [J]. J Non-Crystalline Solids, 1995,190(3) : 264--275.
  • 5BAE J Y, JUNG J I, SEO S J, et al. Formation and thermal-induced changes of mesostructures in fluorinated organosilicate films [J]. Microporous and Mesoporous Materials, 2007,98 ( 1 -- 3): 283--291.
  • 6PARVATHY R A, VENKATESWARA R A, PAJONK G M. Hydrophobic and physical properties of the ambient pressure dried silica aerogels with sodium silicate precursor using various surface modification agents [J]. Applied Surface Science, 2007, 253 (14) : 6032--6040.
  • 7IWAMOTO Y, SATO K, KATO T, et al. A hydrogen-permselective amorphous silica membrane derived from polysilazane [J]. Journal of the European Ceramic Society, 2005,25 (2--3) : 257-- 264.
  • 8NOMURA M, ONO K, GOPALAKRISHNAN S, et al. Preparation of a stable silica membrane by a counter diffusion chemical vapor deposition method [J]. Journal of Membrane Science, 2005,251(1--2) :151--158.
  • 9ROUESSAC V, FERREIRA P, DURAND J. Preparation of silica membranes inside macroporous alumina tubes by PECVD for hydrogen selectivity[J]. Separation and Purification Technology, 2003,32 (1--3): 37--43.
  • 10GOPALAKRISHNAN S, YOSHINO Y, NOMURA M, et al. A hybrid processing method for high performance hydrogen-selective silica membranes [J]. Journal of Membrane Science, 2007,297 (1 --2): 5--9.

共引文献21

同被引文献22

引证文献5

二级引证文献3

相关作者

内容加载中请稍等...

相关机构

内容加载中请稍等...

相关主题

内容加载中请稍等...

浏览历史

内容加载中请稍等...
;
使用帮助 返回顶部