Theoretical study on the interactions between chlordecone hydrate and acidic surface groups of activated carbon under basic pH conditions

Explaining the interactions between metaldehyde and acidic surface groups of activated carbon under different pH conditions

“…This model neglects the influence of pore shape, defects, pore size and pore connectivity, but instead allows the performance of a large number of calculations with a higher theoretical level, in order to achieve a better chemical description of the studied phenomena. Although, it has been studied that hydroxyl groups may be located in the basal plane of the carbonaceous surface [35], and could play an important role in the adsorption process, the selected model [22,23] in this study only considers modifications in the edge of coronene that do not affect the aromaticity of the system. Depicted in Figure 1b, the models provide both the aromatic character (or graphene structure) and the SGs at the edges of AC.…”

“…The application of computational chemistry methods allow an economization of the material resources while optimizing the work and security of the researchers and technicians [16]. The influence of surface groups (SG) content over adsorption properties has been reported and studied to some extent theoretically for porous carbons (mainly AC and soot particles) [9,[17][18][19][20][21][22][23] in the last few years employing different AC models. In 2014 Enriquez-Victorero et.…”

“…al [22], while studying adsorption of chlordecone into AC, established a work flow that incorporated Quantum Theory of Atoms in Molecules [28,29] to the methods used by Hernández-Valdés et al [21] for quantitatively describing the interactions presents in the studied systems. This strategy was later used by Melchor et al [23] for describing the interactions at a basic pH of hydrated chlordecone with an AC, which, when coupled with the results by Gamboa-Carballo et. al [22] allows the characterization of the absorption of this pollutant in a wide pH range, and to match the theoretical calculations with experimental adsorption isotherms.…”

Evaluation of the molecular inclusion process of β-hexachlorocyclohexane in cyclodextrins

“…38 Although the Gibbs free energy of association (DG assoc ) is the thermodynamic criterion used to dene the spontaneity of a process, here, the association energy (DE assoc ) was preferred. This criterion has been widely used in the past [39][40][41][42] because it is simpler from a computational point of view; also, it avoids the necessity of calculating the association entropies. DE assoc is dened as:…”

“…A favorable thermodynamic association implies that the supermolecule will be more stable than the isolated molecules; namely, a greater absolute value of DE assoc corresponds to more energetically favorable associations. The MMH methodology usually works with semiempirical methods [39][40][41][42][43][44] for the evaluation of the energies while using statistical mechanics to obtain thermodynamic properties related to the molecular association. 38 The main procedure of this approach constructs several random non-redundant molecular geometries, starting from the independently optimized structures of the interacting molecules, in order to explore the conguration space of the formed complexes.…”