Pyridine transport diffusion coefficient

Gas transport coefficients of PVC and PVC modified with pyridine groups were studied. It was found that there is a strong time dependence of the permeability and diffusivity of oxygen, nitrogen, carbon dioxide and methane in membranes prepared by solvent casting of PVC and pyridine modified PVC. There is a two-fold reduction for PVC of the diffusion coefficients during the first two days,... 

Catalytic supercritical water oxidation is an important class of solid-catalyzed reaction that utilizes advantageous solution properties of supercritical water (dielectric constant, electrolytic conductance, dissociation constant, hydrogen bonding) as well as the superior transport properties of the supercritical medium (viscosity, heat capacity, diffusion coefficient, and density). The most commonly encountered oxidation reaction carried out in supercritical water is the oxidation of alcohols, acetic acid, ammonia, benzene, benzoic acid, butanol, chlorophenol, dichlorobenzene, phenol, 2-propanol (catalyzed by metal oxide catalysts such as CuO/ZnO, Ti02, MnOz, KMn04, V2O5, and Cr203), 2,4-dichlorophenol, methyl ethyl ketone, and pyridine (catalyzed by supported noble metal catalysts such as supported platinum). ... 

When the strong acidity of the MFI zeolite (H-ZSM-5) was removed via ion exchange, as in the case of Li-ZSM-5 or Na-ZSM-5, or was intrinsically absent, as in the case of silicalite-1, adsorption of pyridine was entirely reversible, and reasonable ( corrected ) diffusion coefficients were obtained. As an example. Fig. 12 illustrates the reversible pyridine adsorption into and desorption out of Li-ZSM-5. The diffusion coefficient of pyridine transport in... 

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