RF-aerogels catalysed by ammonium carbonate
RF-aerogels catalysed by ammonium carbonate
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DOI：
10.1007/s10971-009-2060-9
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发表时间：
2010
影响因子：
2.5
通讯作者：
M. Reuss;L. Ratke
中科院分区：
文献类型：
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作者：
M. Reuss;L. Ratke
与碳酸钠等传统催化剂不同，应用碳酸铵(AC)作为催化剂制备射频气凝胶可以得到无金属杂质的有机气凝胶。为了合成AC催化的RF气凝胶，我们在很大范围内改变了催化剂和甲醛浓度。纳米结构相应地在一个数量级上发生变化。用扫描电子显微镜测定，干气凝胶网络中的颗粒尺寸在0.15-4gμm之间。气凝胶密度在370-420g/m−3之间。氮气吸附测定的比表面积在0.5g-13g−-1之间变化，这相当于比表面积从0.7g-20gμm−-1。
The application of ammonium carbonate (AC) as catalyst for the preparation of RF-aerogels leads to organic aerogels without metallic impurities in contrast to conventional catalysts like sodium carbonate. To synthesize the AC catalyzed RF aerogels we varied the catalyst and formaldehyde concentration in wide ranges. The nanostructure varies accordingly over an order of magnitude. The particle sizes in the dry aerogel network, determined by scanning electron microscopy, are in the range of 0.15–4 μm. The aerogel densities are in the range of 370–420 kg m−3. The specific surface measured by nitrogen adsorption (BET) varies from 0.5 to 13 m2g−1which equals a specific surface area from 0.7 to 20 μm−1. Thermogravimetry is employed to study the drying process, annealing reactions and decomposition of the aerogel into a carbon aerogel.