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Aerogels from Unaltered Bacterial Cellulose: Application of scCO2 Drying for the Preparation of Shaped,Ultra‐Lightweight Cellulosic Aerogels |
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| Authors: | Falk Liebner Emmerich Haimer Martin Wendland Marie‐Alexandra Neouze Kerstin Schlufter Peter Miethe Thomas Heinze Antje Potthast Thomas Rosenau |
| Affiliation: | 1. Institute of Organic Chemistry, University of Natural Resources and Applied Life Sciences Vienna, Muthgasse 18, A‐1190 Vienna, Austria;2. Institute of Chemical and Energy Engineering, University of Natural Resources and Applied Life Sciences Vienna, Muthgasse 107, A‐1190 Vienna, Austria;3. Vienna University of Technology, Institute of Material Chemistry, Getreidemarkt 9/165, A‐1060 Vienna, Austria;4. fzmb GmbH – Research Centre for Medical Technology and Biotechnology, Geranienweg 7, D‐99947 Bad Langensalza, Germany;5. Friedrich Schiller University Jena, Centre of Excellence for Polysaccharide Research, Humboldtstr. 11, D‐07743 Jena, Germany |
| Abstract: | Bacterial cellulose produced by the gram‐negative bacterium Gluconacetobacter xylinum was found to be an excellent native starting material for preparing shaped ultra‐lightweight cellulose aerogels. The procedure comprises thorough washing and sterilization of the aquogel, quantitative solvent exchange and subsequent drying with supercritical carbon dioxide at 40 °C and 100 bar. The average density of the obtained dry cellulose aerogels is only about 8 mg · cm?3 which is comparable to the most lightweight silica aerogels and distinctly lower than all values for cellulosic aerogels obtained from plant cellulose so far. SEM, ESEM and nitrogen adsorption experiments at 77 K reveal an open‐porous network structure that consists of a comparatively high percentage of large mesopores and smaller macropores.  |
| Keywords: | aerogels bacterial cellulose biopolymers porosity renewable resources ultra‐lightweight materials |