Porosity and Dynamics of Encapsulated Molecules

The porosity of sol-gel materials is a fundamental characteristic that often needs to be finely characterized. Several physicochemical techniques can be implemented, for example, Xe NMR spectroscopy. Thermally polarized xenon NMR has been used for decades for the characterization of porous materials such as zeolites, mesoporous silicas, and silica glasses, but the technique has been largely improved with the introduction of hyperpolarization of xenon gas via optical pumping methods. In this case, spin polarization can be enhanced 

Solid-state NMR spectroscopy has always been a valuable investigation tool for sol-gel scientists. In this chapter, the aim was to focus on recent advances in 

The authors thank the Ph.D. students, postdoctoral fellows, and collaborators who contributed at various levels to the projects described in this chapter, and more specifically the group of Prof. G. Bodenhausen (EPFL, Switzerland) for the DNP experiments and the group of Dr. D. Sakellariou (CEA Saclay, France) for the MACS experiments. 

1 Laws, D.D., Bitter, H.-M.L., and Jerschow, A. (2002) Solid-state NMR spectroscopic methods in chemistry. Angew. Chem., Int Ed., 41,3096-3129. 

2 Bonhomme, C., Coelho, C., Bacdle, N., Gervais, C, Azaiis, T., and Babonneau, F. (2007) Advanced solid state NMR techniques for the characterization of sol-gel-derived materials. Acc. Chem. Res., 40, 738-746. 

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