Intrapore field-dependent micropore filling of supercritical N2 in slit-shaped micropores

Abstract

The micropore filling of supercritical N2 on micrographitic carbon fibers having slit-shaped micropores of different micropore widths from 0.7 to 1.4 nm was examined at 303 K under the high pressure of N2 up to 10 MPa. Supercritical N2 in the micropore was presumed to be transformed into quasivapor by strong micropore field; the Dubinin–Radushkevich equation for a vapor was extended to the quasivapor in the micropore. The determination method of the saturated vapor pressure Psq of the quasi-N2 vapor in the micropore was proposed and was applied to the experimental results on N2/micrographitic carbon fiber systems; the determined Psq increases with the micropore width. The relationship between the extent of micropore filling of a supercritical gas through the quasivapor state and the interaction energy between a molecule and two parallel micrographites from the Lennard-Jones potential was theoretically derived, which was evidenced by the simple experimental relationship between the amount of high pressure N2 adsorption at 303 K and the micropore width.

Translational diffusion of water inside hydrophobic carbon micropores studied by neutron spectroscopy and molecular dynamics simulation

“…The remainder of the pore volume consists of largely random mesopores and some ultra-micropores. Various other measurements including thermodynamics [18,22], small-angle neutron and X-ray scattering [23,24] of ACF-10 have also confirmed the interconnected pore structure of ACF-10, which is made primarily of elongated curvy slit-pores. The pores themselves are just the voids or gaps between distorted (curled or curved, and not necessarily parallel) graphene sheets, much like empty spaces within a dense pile of potato chips, but comparatively smaller [25].…”

Adsorption and selectivity of carbon dioxide with methane and nitrogen in slit-shaped carbonaceous micropores: Simulation and experiment

“…The pore width, H, is the distance between carbon centres on the opposite wall of the micropore. A real microporous activated carbon is likely to be composed of pores of various widths, thus making the adsorbent energetically heterogeneous, although recently certain activated carbon fibres have been shown to have a very narrow pore size distribution (Kaneko et al, 1992) having pore shapes consistent with the slit model.…”

Carbon Aerogels: a study with different models of the effect resorcinol/catalyst at different ratios after pyrolysis and the effect on textural properties

“…Several authors [15][16][17][18][19][20][21] have conducted studies to evaluate adequately and systematically porosity that develops in carbon materials by different methods, including the effect pore subtraction method (SPE) using the graphics high αs resolution, for N2 adsorption isotherms at 77 K by which they can properly evaluate the structure of micropores [15,19]. According to these authors, to apply the analysis of highresolution αs it is possible to find adequate information on the microporosity developed in the process of synthesis of aerogels, as well as of the mesoporosity [22] that are in good agreement with other methods that have been used for several decades [23][24][25].…”