Hypercrosslinked polyanilines with nanoporous structure and high surface area:: potential adsorbents for hydrogen storage
Hypercrosslinked polyanilines with nanoporous structure and high surface area:: potential adsorbents for hydrogen storage
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DOI：
10.1039/b711509a
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发表时间：
2007-01-01
影响因子：
--
通讯作者：
Svec, Frantisek
中科院分区：
文献类型：
--
作者：
Germain, Jonathan;Frechet, Jean M. J.;Svec, Frantisek
本文报道了一种新型纳米多孔材料--超高交联聚苯胺的制备方法，该材料具有永久性多孔结构，比表面积超过630 m ~（2）g ~（-1）。用常规方法和微波辅助方法，用商品聚苯胺与二碘代烷烃或多聚甲醛进行了超交联反应。在有机溶剂中溶胀的聚苯胺被高度交联以形成具有永久多孔性和高表面积的刚性网状结构。使用红外光谱和元素分析对所得材料进行表征。通过扫描电子显微镜以及氮气和氢气吸附测定多孔性能。短的交联，如使用多聚甲醛和二碘甲烷形成的那些，导致材料具有最高的表面积。表面积也随着制备过程中所用溶液中聚苯胺的浓度而增加。这些材料的储氢容量也进行了测试，并发现在77 K和3.0 MPa的最佳吸附剂的容量为2.2重量%。超交联聚苯胺表现出对氢的非常高的亲和力，这导致高达9.3 kJ mol（-1）的吸附能（放热），与超交联聚苯乙烯和金属有机框架形成鲜明对比，对于它们，测量到显著较低的吸附能，通常在4-7 kJ mol（-1）的范围内。
A method for the preparation of an entirely new type of nanoporous material, hypercrosslinked polyaniline, with permanent porous structure and specific surface areas exceeding 630 m(2) g(-1) has been developed. The hypercrosslinking reaction was carried out with commercial polyaniline and diiodoalkanes or paraformaldehyde using both conventional and microwave assisted processes. Polyaniline swollen in an organic solvent was hypercrosslinked to form a rigid, mesh-like structure with permanent porosity and a high surface area. The resulting materials were characterized using infrared spectroscopy and elemental analysis. Porous properties were determined by means of scanning electron microscopy as well as nitrogen and hydrogen adsorption. Short crosslinks such as those formed using paraformaldehyde and diiodomethane led to materials with the highest surface areas. Surface area also increased with the concentration of polyaniline in solution used during preparation. The hydrogen storage capacities of these materials were also tested and a capacity of 2.2 wt% at 77 K and 3.0 MPa was found for the best adsorbent. Hypercrosslinked polyanilines exhibit a remarkably high affinity for hydrogen, which results in enthalpies of adsorption as high as 9.3 kJ mol(-1) (exothermic), in sharp contrast with hypercrosslinked polystyrenes and metal-organic frameworks for which significantly lower enthalpies of adsorption, typically in the range of 4-7 kJ mol(-1), are measured.