Adsorption properties of surface of carbon materials at extremely low coverages

Abstract

Adsorption properties of blacks and their graphitized analogues were examined by the inverse gas chromatography at extremely low surface coverage.

Thermodynamic N2 Vapor Isotherms of Materials: Zeta Adsorption Isotherm Approach

“…We examined in Section the adsorption properties of N 2 on two nonoxide materials: carbon black and graphitized carbon. It is well reported in the literature that both of these materials vary in heterogeneities due to the differences in their functional groups, graphitic domains, and imperfections. , Nitrogen adsorption studies have been reported extensively on these two carbons ,,− to reveal their surface properties. The surface characterization of such carbon materials is usually done by the BET method using the adsorption data in a narrow low-pressure range, which is generally marked by micropore filling ,, and/or phase change of the adsorbate on graphitic basal planes. , The current ZAI analysis avoids these heterogeneities to determine the thermodynamic isotherms.…”

Inversion gas chromatography in studies of adsorption properties of the surface of carbon materials: Dispersion component of the surface free energy

“…In our previous communication [15] we reported the basic surface characteristics of the carbon blacks considered in the present study and described in detail procedures used to prepare the given adsorbents for a chromatographic analysis.…”

“…where γ CH 2 (mJ m -2 ) is a part of the free energy, which corresponds to adsorption of a single CH 2 group, γ CH 2 = 35.6 + 0.058[293 -T(K)] [19]; σ CH 2 , surface area of a methylene unit in n-alkanes (0.06 nm 2 ); Δ(G -°1 ,C ) CH 2 , adsorption energy of a CH 2 group on the given adsorbent, which can be calculated as (2) Values of V A,1 were determined from experimental retentions of n-pentane and n-hexane by the method described in detail in [15,16]. The working temperature range was 373-473 K. It should be noted that the values of V A,1 were found under conditions close to zero surface fi lling [16].…”

“…Our study continues a research series into adsorptionchromatographic surface properties of various carbon materials by inversion gas chromatography [15][16][17].…”