National Research Council of Canada. Energy, Mining and Environment
Polymers of intrinsic microporosity (PIMs) can be functionalized with nitrogen-bearing groups, such as a nitrile group for PIM-1 and a methylated tetrazole group for MTZ-PIM, to physisorb CO2. Static 13C NMR spectroscopy was used to investigate CO2 dynamics by analysis of onedimensional spectra and T2 relaxation times at temperatures ranging from 6 to 295 K. Each polymer had two different loadings of CO2 to determine the dominating relaxation mechanism at lower temperatures and deduce the identity of the weaker secondary adsorption site on the rigid polymer backbone. Both polymers, with a high loading of CO2, experience a narrowing of the 13C NMR line width as the samples are warmed to 80 K, which is the onset of the weakly adsorbed CO2 hopping on and off the polymer backbone.
American Chemical Society
The Journal of Physical Chemistry C122, no. 8: 4403–4408.