Department of Colloid Chemistry, Max-Planck-Institute of Colloids and Interfaces, Science Park Golm, D-14424, Potsdam, Germany.
Langmuir. 2010 Oct 5;26(19):15650-6. doi: 10.1021/la1028806.
The microporosity of two microporous polymer networks is investigated in detail. Both networks are based on a central spirobifluorene motif but have different linker groups, namely, imide and thiophene units. The microporosity of the networks is based on the "polymers of intrinsic microporosity (PIM)" design strategy. Nitrogen, argon, and carbon dioxide were used as sorbates in order to analyze the microporosity in greater detail. The gas sorption data was analyzed with respect to important parameters such as specific surface area, pore volume, and pore size (distribution). It is shown that the results can be strongly model dependent and swelling effects have to be regarded. (129)Xe NMR was used as an independent technique for the estimation of the average pore size of the polymer networks. The results indicate that both networks are mainly ultramicroporous (pore sizes < 0.8 nm) in the dry state, which was not expected based on the molecular design. Phase separation and network defects might influence the overall network morphology strongly. Finally, the observed swelling indicates that this "soft" microporous matter might have a different micropore size in the solvent swollen/filled state that in the dry state.
详细研究了两种微孔聚合物网络的微孔率。这两个网络都基于中心螺双芴基，但具有不同的连接基团，即酰亚胺和噻吩单元。网络的微孔率基于“本征微孔聚合物（PIM）”设计策略。使用氮气、氩气和二氧化碳作为吸附质，以便更详细地分析微孔率。使用比表面积、孔体积和孔径（分布）等重要参数对气体吸附数据进行了分析。结果表明，结果可能强烈依赖于模型，并且必须考虑溶胀效应。（129）Xe NMR 被用作估计聚合物网络平均孔径的独立技术。结果表明，在干燥状态下，这两个网络主要都是超微孔的（孔径 < 0.8nm），这与分子设计预期的结果不一致。相分离和网络缺陷可能会强烈影响整个网络形态。最后，观察到的溶胀表明，这种“软”微孔物质在溶剂溶胀/填充状态下的微孔尺寸可能与在干燥状态下不同。
