Cellulose aerogels from aqueous alkali hydroxide-urea solution
Cellulose aerogels from aqueous alkali hydroxide-urea solution
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DOI：
10.1002/cssc.200700039
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发表时间：
2008-01-01
期刊：
影响因子：
8.4
通讯作者：
Zhang, Lina
中科院分区：
文献类型：
--
作者：
Cai, Jie;Kimura, Satoshi;Zhang, Lina
通过将碱金属氢氧化物/尿素水溶液凝胶化纤维素，然后用超临界 CO2 干燥，制备了高孔隙率和强纤维素气凝胶。通过扫描和透射电子显微镜、X 射线衍射、氮吸附测量、紫外/可见光谱和拉伸测试对其形态、孔结构和物理性能进行了表征。纤维素水凝胶由约20 nm宽的互连原纤维组成。通过使用超临界CO2干燥，水凝胶中的网络结构在气凝胶中得到了很好的保存。结果是初步的，但证明了该方法能够产生大表面积（400-500 m(2)g(-1)）的纤维素气凝胶，其可用作吸附剂、隔热/隔音体、过滤器、催化剂载体或碳气凝胶前体。
Highly porous and strong cellulose aerogels were prepared by gelation of cellulose from aqueous alkali hydroxide/urea solution, followed by drying with supercritical CO2 Their morphology, pore structure, and physical properties were characterized by scanning and transmission electron microscopy, X-ray diffraction, nitrogen adsorption measurements, UV/Vis spectrometry, and tensile tests. The cellulose hydrogel was composed of interconnected fibrils of about 20 nm wide. By using supercritical CO2 drying, the network structure in the hydrogel was well preserved in the aerogel. The results are preliminary but demonstrate the ability of this method to give cellulose aerogels of large surface areas (400-500 m(2)g(-1)) which may be useful as adsorbents, heat/sound insulators, filters, catalyst supports, or carbon aerogel precursors.