Nitrogen and Argon Adsorption and SEM Characterization of C₆₀ and C₆₀/C₇₀ Fullerenes:  Comparison with Graphite

Abstract

The surface and pore structure properties of the C60 and C60/C70 fullerene powders were studied by means of scanning electron microscopy, helium pycnometry, and 77.4 K nitrogen and argon adsorption. The pore structure of fullerene powders is macroporous and consists mainly of the voids between the fullerene aggregates. In the major part of the adsorption monolayer, both nitrogen and argon interactions with fullerenes are weaker than with graphite, possibly because of the reduction of the gas molecule−mirror image effect in the case of fullerenes. In Henry's law limit, however, nitrogen and argon adsorption on fullerenes is quantitatively similar to that on graphite because of the adsorption potential enhancement in the spaces between the surface fullerene molecules. In the multilayer regime, nitrogen adsorption on both fullerenes becomes similar to that on graphite. Both fullerenes behave similarly with respect to the adsorption of the studied gases.

Adsorption and phase transitions on nanoporous carbonaceous materials: insights from molecular simulations

“…generally accepted N 2 cross-sectional area of 0.162 nm 2 [42]. Generally the prediction is in good agreement with experimental results [5], though there is relatively large deviation at high pressures. The deviation may be attributed to several factors: first, an empirical potential based on N 2 adsorption on graphite is used, which perhaps is not accurate; second, a rigid f.c.c.…”

“…The adsorption of N 2 [4][5][6], Kr [4], and Ar [6] near 77 K were measured and the isotherms were found to be of type II. The surface heterogeneity of the C 60 crystal has been examined by infrared spectroscopy of adsorbed CO, and the spectral shifts indicated that different types of adsorption sites exist on the surface [7,8].…”

“…Isotherm for N 2 adsorption on the surface of the C 60 crystal at 77.3 K as a function of reduced pressure. The triangles are from experiment [5], and the circles are from prediction. generally accepted N 2 cross-sectional area of 0.162 nm 2 [42].…”

Physical Adsorption of Ar and CO2 on C60 Fullerene

“…Thus, Ismail and Rodgers studying Kr, N 2 , O 2 , and CO 2 adsorption, and Kaneko et al, using N 2 and O 2 adsorption, agreed in finding micropores in C 60 ; Ismail and Rodgers had already pointed out that surface area values might vary from one batch to another, depending on sample preparation and purification, as well as sample age. More recent work − indicates, however, that fullerene powders with higher degrees of purity consist of nonporous particles. As expected for any solid, the porous texture of fullerenes is very sensitive to the synthesis and purification procedures followed in their preparation.…”

Understanding Layer Promotion and Its Relationship to Melting in Krypton on Graphite Using Artificial Constraints

“…Although there has been significant interest and effort in understanding the behavior of systems physisorbed onto spherical substrates [18][19][20][21][22][23][24][25][26][27], systems adsorbed onto Fullerenes [28][29][30][31][32][33][34] and even Fullerenes and their interactions [35][36][37][38][39][40][41][42][43][44][45][46],…”