Published in:Research Letters in Materials Science
Language:
English
DOI:
10.1155/2007/73724
ISSN:
1687-6822;
1687-6830
Origination:
Footnote:
Description:
<jats:p>Cellulose aerogels are intriguing new materials produced by supercritical drying of regenerated cellulose obtained by solvent exchange of solid Lyocell moldings. From<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E1"><mml:mi>N</mml:mi></mml:math>-methylmorpholine-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E2"><mml:mi>N</mml:mi></mml:math>-oxide solutions with cellulose contents between 1 and 12<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E3"><mml:mi>%</mml:mi></mml:math>, 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/<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E4"><mml:mrow><mml:msup><mml:mrow><mml:mtext>cm</mml:mtext></mml:mrow><mml:mn>3</mml:mn></mml:msup></mml:mrow></mml:math>and from 172 to 284<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="E5"><mml:mrow><mml:msup><mml:mtext>m</mml:mtext><mml:mn>2</mml:mn></mml:msup></mml:mrow></mml:math>/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.</jats:p>