Dieses Dokument steht unter einer CreativeCommons Lizenz by-nc-nd/3.0
Verlagslink DOI: 10.3791/54116
Titel: Preparation of biopolymer aerogels using green solvents
Sprache: English
Autor/Autorin: Raman, Subrahmanyam 
Gurikov, Pavel 
Meissner, Imke 
Smirnova, Irina 
Schlagwörter: Chemistry;Issue 113;Biopolymers;aerogels;supercritical CO2 drying;green solvents;amidated pectin;hydrogels
Erscheinungsdatum: 4-Jul-2016
Verlag: [S.l.]
Quellenangabe: Journal of Visualized Experiments 113 (2016): - (2016-07-04)
Zeitschrift oder Schriftenreihe: JoVE 
Zusammenfassung (englisch): Although the first reports on aerogels made by Kistler1 in the 1930s dealt with aerogels from both inorganic oxides (silica and others) and biopolymers (gelatin, agar, cellulose), only recently have biomasses been recognized as an abundant source of chemically diverse macromolecules for functional aerogel materials. Biopolymer aerogels (pectin, alginate, chitosan, cellulose, etc.) exhibit both specific inheritable functions of starting biopolymers and distinctive features of aerogels (80-99% porosity and specific surface up to 800 m2/g). This synergy of properties makes biopolymer aerogels promising candidates for a wide gamut of applications such as thermal insulation, tissue engineering and regenerative medicine, drug delivery systems, functional foods, catalysts, adsorbents and sensors. This work demonstrates the use of pressurized carbon dioxide (5 MPa) for the ionic cross linking of amidated pectin into hydrogels. Initially a biopolymer/salt dispersion is prepared in water. Under pressurized CO2 conditions, the pH of the biopolymer solution is lowered to 3 which releases the crosslinking cations from the salt to bind with the biopolymer yielding hydrogels. Solvent exchange to ethanol and further supercritical CO2 drying (10 - 12 MPa) yield aerogels. Obtained aerogels are ultra-porous with low density (as low as 0.02 g/cm3), high specific surface area (350 - 500 m2/g) and pore volume (3 - 7 cm3/g for pore sizes less than 150 nm).
URI: https://tubdok.tub.tuhh.de/handle/11420/2000
DOI: 10.15480/882.1997
ISSN: 1940-087X
Institut: Thermische Verfahrenstechnik V-8 
Dokumenttyp: (wissenschaftlicher) Artikel
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