Supercritical drying of aerogels using CO2: Effect of extraction time on the end material textural properties

被引:272
作者
Garcia-Gonzalez, C. A. [1 ]
Camino-Rey, M. C. [1 ]
Alnaief, M. [2 ]
Zetzl, C. [1 ]
Smirnova, I. [1 ]
机构
[1] Hamburg Univ Technol, Inst Thermal Separat Proc, D-21073 Hamburg, Germany
[2] German Jordanian Univ, Sch Appl Med Sci, Amman 11180, Jordan
关键词
Aerogel; Supercritical drying; Textural properties; Drying time; SILICA AEROGEL; CARBON-DIOXIDE; LIQUID CO2; ETHANOL; DIFFUSION; EQUILIBRIA; METHANOL; REMOVAL; DENSITY; FILMS;
D O I
10.1016/j.supflu.2012.02.026
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Aerogel technology provides high added-value lightweight materials with outstanding textural properties (i.e., high surface area and open porosity). Aerogels are obtained from wet gels by using a suitable drying technology, usually supercritical drying process, able to avoid the pore collapse phenomenon in order to keep intact the porous texture of the wet material. In this sense, the study of the kinetic profile of the gel supercritical drying is regarded as a key aspect to be considered in the specific case of the design of aerogel-based systems. In this work, the drying profile with supercritical carbon dioxide (scCO(2)) of alcogels (in ethanol) was determined using a customized supercritical fluid extraction equipment. The drying of alcogels from different precursors (inorganic-silica-, organic-starch-), densities (silica aerogel of densities 0.08 and 0.15 g/cm(3)) and morphologies (cylindrical monoliths, microspheres) was studied. Depending on the nature of the gel precursor, the extent of drying (i.e., drying time duration) gave significant differences in the end textural properties of the dried gel. (c) 2012 Elsevier B.V. All rights reserved.
引用
收藏
页码:297 / 306
页数:10
相关论文
共 70 条
[21]   Freeze-drying of bioproducts: putting principles into practice [J].
Franks, F .
EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS, 1998, 45 (03) :221-229
[22]   Polysaccharide-based aerogels-Promising biodegradable carriers for drug delivery systems [J].
Garcia-Gonzalez, C. A. ;
Alnaief, M. ;
Smirnova, I. .
CARBOHYDRATE POLYMERS, 2011, 86 (04) :1425-1438
[23]   New insights on the use of supercritical carbon dioxide for the accelerated carbonation of cement pastes [J].
Garcia-Gonzalez, Carlos A. ;
el Grouh, Nadia ;
Hidalgo, Ana ;
Fraile, Julio ;
Lopez-Periago, Ana M. ;
Andrade, Carmen ;
Domingo, Concepcion .
JOURNAL OF SUPERCRITICAL FLUIDS, 2008, 43 (03) :500-509
[24]   Temperature related structural changes in wheat and corn starch granules and their effects on gels and dry foam [J].
Glenn, Gregory M. ;
Klamczynski, Artur ;
Chiou, Bor-Sen ;
Orts, William J. ;
Imam, Syed H. ;
Wood, Delilah F. .
STARCH-STARKE, 2008, 60 (09) :476-484
[25]  
Gómez TE, 2002, ULTRASON, P1107
[26]   Silica Aerogel: Synthesis and Applications [J].
Gurav, Jyoti L. ;
Jung, In-Keun ;
Park, Hyung-Ho ;
Kang, Eul Son ;
Nadargi, Digambar Y. .
JOURNAL OF NANOMATERIALS, 2010, 2010
[27]   Ambient pressure dried TEOS-based silica aerogels: good absorbents of organic liquids [J].
Gurav, Jyoti L. ;
Rao, A. Venkateswara ;
Nadargi, D. Y. ;
Park, Hyung-Ho .
JOURNAL OF MATERIALS SCIENCE, 2010, 45 (02) :503-510
[28]   Formation of acid sites in amorphous silica-alumina [J].
Hensen, E. J. M. ;
Poduval, D. G. ;
Magusin, P. C. M. M. ;
Coumans, A. E. ;
van Veen, J. A. R. .
JOURNAL OF CATALYSIS, 2010, 269 (01) :201-218
[29]  
Hüsing N, 1998, ANGEW CHEM INT EDIT, V37, P23, DOI 10.1002/(SICI)1521-3773(19980202)37:1/2<22::AID-ANIE22>3.0.CO
[30]  
2-I