The Basicity of Carbons

Copper and zinc adsorption by softwood and hardwood biochars under elevated sulphate-induced salinity and acidic pH conditions

“…Higher cation exchange capacity of jarrah biochar may be one of the important factors contributing to its higher adsorption capacity than pine biochar (Table S3). In particular, jarrah biochar contained a much higher concentration of exchangeable Ca 2+ , which contributed to the basicity of biochar surfaces (Montes-Morán et al, 2012). The release of base cations from carbon surfaces through ion exchange and dissolution contributes to the formation of negative surface charge and alkalinity (Moreno-Castilla and Rivera-Utrilla, 2001).…”

Protein adsorption and activity on carbon xerogels with narrow pore size distributions covering a wide mesoporous range

“…Thus, taking values of the unit cell of the horse heart cyt c (and assuming that they are essentially the same for the bovine heart cyt c used here) [39], a density of 0.17 g cm -3 results. Pore filling percentages can be thus estimated for the different carbon xerogels (Table 4, xerogels or, alternatively, the lack of a rich surface chemistry despite of its basic character [41]. For these particular materials, protein/carbon surface hydrophobic interactions would control the adsorption process.…”

Comparative Study of Toluene and Hexane Adsorption on Activated Carbons From Gas and Liquid Phase. Enthalpy and Isotherms

“…Regarding to the samples, Figure 12 shows the immersion enthalpies of pure solvents and toluene-hexane mixtures in function of the molar fraction of toluene and the total acidity and basicity of samples. It can be seen that the immersion enthalpies increased with basicity and decrease with the total acidity of the samples, this occurred because according to other investigations the electron density of the adsorbent depended on its type of surface chemistry: electron withdrawing groups (like oxygen surface groups) reduced the adsorptive potential of the material whereas donating functional groups favored the electron density and then the adsorptive potential of the carbonaceous solid Montes-Morán et al, 2012;Rubahamya et al, 2019). This is why enthalpies for CS were lower than for CST, since CS contained higher concentration of acidic oxygen groups, which reduced the electron density and the potential adsorptive of activated carbon, as well as the adsorption affinity by ππ interactions (Goto et al, 2015), generating less adsorbate-adsorbent interaction, mainly with toluene; the opposite occurred with CST since when it was subjected to high temperature, electron withdrawing groups were removed and at the same time the concentration of aromatic rings in the solid structure was intensified (Contescu et al, 2018), increasing its electron density and therefore, the intensity of the interaction adsorbent-adsorbate was higher.…”

“…Regarding to the samples, electron density of the adsorbent depended on its type of surface chemistry: electron withdrawing groups (like oxygen surface groups) reduced the adsorptive potential of the material whereas donating functional groups favored the electron density and then the adsorptive potential of the carbonaceous solid (Montes-Morán et al, 2012;Rubahamya et al, 2019). This is why enthalpies for CS were lower than for CST, since CS contained higher concentration of acidic oxygen groups, which reduced the electron density and the potential adsorptive of activated carbon, as well as the adsorption 2 | Parameters obtained from the fit to the Langmuir and Freundlich models for the liquid phase adsorption isotherms of toluene/hexane on CS and CST.…”