Kim Sangil, Ida Junichi, Guliants Vadim V, Lin Jerry Y S
Department of Chemical and Materials Engineering, University of Cincinnati, Cincinnati, Ohio 45221-0012, USA.
J Phys Chem B. 2005 Apr 7;109(13):6287-93. doi: 10.1021/jp045634x.
Four different types of amine-attached MCM-48 silicas were prepared and investigated for CO(2) separation from N(2). Monomeric and polymeric hindered and unhindered amines were attached to the pore surface of the MCM-48 silica and characterized with respect to their CO(2) sorption properties. The pore structures and amino group content in these modified silicas were investigated by XRD, FT-IR, TGA, N(2) adsorption/desorption at 77 K and CHN/Si analysis, which confirmed that in all cases the amino groups were attached to the pore surface of MCM-48 at 1.5-5.2 mmol/g. The N(2) adsorption/desorption analysis showed a considerable decrease of the pore volume and surface area for the MCM-48 silica containing a polymeric amine (e.g., polyethyleneimine). The CO(2) adsorption rates and capacities of the amine-attached MCM-48 samples were studied employing a sorption microbalance. The results obtained indicated that in addition to the concentration of surface-attached amino groups, specific interactions between CO(2) and the surface amino groups, and the resultant pore structure after amine group attachment have a significant impact on CO(2) adsorption properties of these promising adsorbent materials.
制备了四种不同类型的胺基连接的MCM-48硅胶，并对其从N₂中分离CO₂的性能进行了研究。将单体和聚合物受阻及未受阻胺连接到MCM-48硅胶的孔表面，并对其CO₂吸附性能进行了表征。通过XRD、FT-IR、TGA、77K下的N₂吸附/脱附以及CHN/Si分析对这些改性硅胶的孔结构和氨基含量进行了研究，结果证实，在所有情况下，氨基均以1.5-5.2 mmol/g的量连接到MCM-48的孔表面。N₂吸附/脱附分析表明，含有聚合物胺（如聚乙烯亚胺）的MCM-48硅胶的孔体积和表面积显著减小。采用吸附微量天平研究了胺基连接的MCM-48样品的CO₂吸附速率和容量。所得结果表明，除了表面连接的氨基浓度外，CO₂与表面氨基之间的特定相互作用以及胺基连接后形成的孔结构对这些有前景的吸附材料的CO₂吸附性能有显著影响。
