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Research Letters in Materials Science
Volume 2007, Article ID 73724, 4 pages
http://dx.doi.org/10.1155/2007/73724
Research Letter

Ultralight-Weight Cellulose Aerogels from NBnMO-Stabilized Lyocell Dopes

1Department of Chemistry, University of Natural Resources and Applied Life Sciences, Muthgasse 18, Vienna 1190, Austria
2Institute of Chemical and Energy Engineering, University of Natural Resources and Applied Life Sciences, Muthgasse 107, Vienna 1190, Austria

Received 6 August 2007; Accepted 5 October 2007

Academic Editor: H. Habazaki

Copyright © 2007 Falk Liebner et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Cellulose aerogels are intriguing new materials produced by supercritical drying of regenerated cellulose obtained by solvent exchange of solid Lyocell moldings. From N-methylmorpholine-N-oxide solutions with cellulose contents between 1 and 12%, dimensionally stable cellulose bodies are produced, in which the solution structure of the cellulose is largely preserved and transferred into the solid state. The specific density and surface of the obtained aerogels range from 0.05 to 0.26 g/cm3 and from 172 to 284 m2/g, respectively, depending on the cellulose content of the Lyocell dopes and regeneration procedure. A reliable extraction and drying procedure using supercritical carbon dioxide, the advantageous use of NBnMO as stabilizer for the Lyocell dopes, and selected physical properties of the materials is communicated.