Institute of Organic Chemistry, University of Natural Resources and Applied Life Sciences Vienna, Muthgasse 18, A-1190 Vienna, Austria.
Macromol Biosci. 2010 Apr 8;10(4):349-52. doi: 10.1002/mabi.200900371.
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 degrees C and 100 bar. The average density of the obtained dry cellulose aerogels is only about 8 mg x 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.
由革兰氏阴性菌木醋杆菌产生的细菌纤维素被发现是一种极好的天然起始材料，可用于制备成型的超轻量纤维素气凝胶。该方法包括对水凝胶进行彻底的清洗和消毒、定量溶剂交换以及随后在 40°C 和 100 巴的超临界二氧化碳中干燥。所得到的干燥纤维素气凝胶的平均密度仅约为 8mg/cm³，与最轻质的二氧化硅气凝胶相当，明显低于迄今为止从植物纤维素获得的所有纤维素气凝胶的值。77K 下的 SEM、ESEM 和氮气吸附实验揭示了一种由相对较高比例的大介孔和较小大孔组成的开式多孔网络结构。
