Alexander Badalyan | PubMed Health

PubMed2005

Sample container temperature gradient influence on the BET specific surface area.

Differences between BET specific surface area (BET SSA) values exist due to data collected in stainless steel and less thermally conductive sample holders. Not accounting for the temperature gradient along stainless steel sample holders during manometric gas adsorption measurements at cryogenic temperatures leads to errors of up to 3.2% in the BET SSA values with a relative combined standard uncertainty (RCSU) of 0.63%. A unidimensional heat flow model accurately accounts for the temperature gradient, leading to an agreement of 0.16% between the BET SSA values for both sample holder units.

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PubMed2002

Activated carbon oxygen content influence on water and surfactant adsorption.

This research investigates the adsorption properties of three activated carbons (AC) derived from coconut, coal, and wood origin. Each carbon demonstrates different levels of resistance to 2 M NaOH treatment. The coconut AC offers the greatest and wood AC the least resistance. The influence of base treatment is mapped in terms of its effects on specific surface area, micropore volume, water adsorption, and dodecanoic acid adsorption from both water and 2 M NaOH solution. A linear relationship exists between the number of water molecules adsorbed at the B-point of the water adsorption isotherm and the oxygen content determined from elemental analysis. Surfactant adsorption isotherms from water and 2 M NaOH indicate that the AC oxygen content effects a greater dependence on affinity for surfactant than specific surface area and micropore volume. We show a linear relationship between the plateau amount of surfactant adsorbed and the AC oxygen content in both water and NaOH phases. The higher the AC oxygen content, the lower the amount of surfactant adsorbed. In contrast, no obvious relationship could be drawn between the surfactant amount adsorbed and the surface area.

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