Characterization of Nano-Porous Silica-Zirconia Aerogels

Author(s):  
Xiao Dong He ◽  
He Xin Zhang ◽  
Yao Li ◽  
Chang Qing Hong
Keyword(s):  
1988 ◽  
Vol 121 ◽  
Author(s):  
Lawrence W. Hrubesh ◽  
Cynthia T. Alviso

ABSTRACTTwo optical methods are described for mapping the local variations of refractive index within monoliths of porous silica aerogel. One is an interferometrie measurement that produces “iso-index” fringes in a two dimensional image; an orthogonal view gives the third dimension information. The other method uses the deflection of a He-Ne laser beam to map the gradient index within a sample. The quantification of the measurements is described and the accuracy of the results is discussed.


1990 ◽  
Vol 65 (2) ◽  
pp. 225-239 ◽  
Author(s):  
C.J.G. van der Grift ◽  
A.Q.M. Boon ◽  
A.J.W. van Veldhuizen ◽  
H.G.J. Trommar ◽  
J.W. Geus ◽  
...  

2004 ◽  
pp. 227-231
Author(s):  
G. L. T. Nascimento ◽  
L. M. Seara ◽  
B. R. A. Neves ◽  
N. D. S. Mohallem

2010 ◽  
Author(s):  
Fulvio Ratto ◽  
Sonia Centi ◽  
Paolo Matteini ◽  
Francesca Rossi ◽  
Roberto Pini
Keyword(s):  

Adsorption ◽  
2005 ◽  
Vol 11 (S1) ◽  
pp. 649-652 ◽  
Author(s):  
Akihiko Matsumoto ◽  
Takahiro Kogawa ◽  
Kazuo Tsutsumi
Keyword(s):  

2012 ◽  
Vol 527 ◽  
pp. 38-43 ◽  
Author(s):  
Juha Larismaa ◽  
Outi Söderberg ◽  
Jesse Syrén ◽  
Eero Haimi ◽  
Simo Pekka Hannula

This paper studies influence of the process temperature and time on the properties of the compacts made of Ag-SiO2 powder by the pulsed electric current sintering (PECS). Silica particles doped with Ag nanoparticles were prepared by modified Stöber method, and calcinated at 573 K in air resulting in average silica particle size of ~1.1 µm and agglomerate size up to 32 µm. There was about 7 wt.% of silver in the structure and the diameter of the silver particles on the silica carriers was 30 ±7 nm on average. The composite powder was sintered into porous compacts by PECS at 873, 973, 1073, or 1173 K for 10, 20, or 30 min under pressure of 50 MPa. Samples were characterized by SEM, XRD, UV-vis-spectrometer, and laser diffraction. During PECS compaction grain growth of silver particles was observed and the measured average size of Ag in 873 K and in 1173 K samples were 65 nm and 170 nm, respectively. The porosity of the materials did not show remarkable change, as the relative density ranged from 76 to 79 %. Thus, it is possible to produce porous silica based materials with controlled Ag-nanoparticle size by PECS. These materials may be optimized for, e.g., different kinds of antibacterial filters.


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