PVT properties and diffusion characteristics of H2O/H2/CO2 mixtures in graphite nanoslits

Diffusivity of CO2 in H2O: A Review of Experimental Studies and Molecular Simulations in the Bulk and in Confinement

“…It is important to note that although these methods have been applied in the literature, many authors continue to apply Einstein’s relation to compute diffusion coefficients in confined media. Overall, the perpendicular component of CO 2 diffusion is lower than the parallel one due to the constraints imposed by the surface in that direction. ,,, Usually, the diffusion coefficient tensor is dependent on the distance from the surface, in such a way that the Smoluchowski equation needs to be solved for each direction in layers parallel to the confining media. When a molecule goes from one layer to another, it no longer contributes to the calculation of the diffusion in its initial layer.…”

“…337 The CVFF 338 has also been applied to model graphene sheets. 339 This force field, however, has been originally parametrized to represent proteins. 338 Sizova et al 340 applied the Steele FF 337 combined with the OPLS-AA 341 to represent, respectively, the carbon atoms and the functional groups in the structure of the CMK-5 mesoporous.…”

“…340 In most cases, the mobility of species increases with temperature. Zhao et al 339 discovered, however, that the diffusion coefficient of hydrogen decreases with temperature in the mixture of CO 2 −H 2 −H 2 O confined by graphene sheets. The increment in the thermal motion of CO 2 and H 2 O molecules with temperature acts like an extra obstruction to small H 2 molecules.…”

“…The increment in the thermal motion of CO 2 and H 2 O molecules with temperature acts like an extra obstruction to small H 2 molecules. 339…”

“…For carbon-derived materials such as carbon nanotubes , the LJ carbon is commonly represented by the chargeless FF from Steele . The CVFF has also been applied to model graphene sheets . This force field, however, has been originally parametrized to represent proteins .…”