Title: Monte Carlo adsorption affinity studio of modified nano-montmorillonite for the removal of chromate ions

Authors: Ana Cadena-Nogales; Alejandro Martiz; Miguel Angel Méndez

Addresses: Grupo de Química Computacional y Teórica (QCT-USFQ), Depto. Ing. Química, Universidad San Francisco de Quito, Diego de Robles y Vía Interoceánica, 17-1200-841, Quito, Ecuador; Grupo Ecuatoriano para el Estudio Experimental y Teórico de Nanosistemas (GETNano), Universidad San Francisco de Quito, Edificio Newton, Oficina N102-C, Diego de Robles y Vía Interoceánica, 17-1200-841, Quito, Ecuador ' Grupo de Química Computacional y Teórica (QCT-USFQ), Depto. Ing. Química, Universidad San Francisco de Quito, Diego de Robles y Vía Interoceánica, 17-1200-841, Quito, Ecuador; Escuela Superior Politécnica del Litoral, ESPOL, Facultad de Ingeniera Mecánica y Ciencias de la Producción-Centro de Investigación y Desarrollo en Nanotecnología, Escuela Superior Politécnica del Litoral, CIDNA-ESPOL, Km. 30.5 Vía Perimetral, P.O. Box 09-01-5853, Guayaquil, Ecuador ' Grupo de Química Computacional y Teórica (QCT-USFQ), Depto. Ing. Química, Universidad San Francisco de Quito, Diego de Robles y Vía Interoceánica, 17-1200-841, Quito, Ecuador

Abstract: A biosurfactant, n-hexadecyl-1-beta-D-maltopyranoside (HMP), and a broadly used cationic surfactant, hexadecyltrimethylammonium (HDTMA), were used as montmorillonite clay modifiers for an in silico study to explore the most stable adsorption sites for the trapping of chromate (CrO4−2) contaminant. Monte Carlo searches have been used to find low energy configurations of substrate with the adsorbate to identify the possible adsorption sites. There was found that the CrO4 proximity of the polar head of the HDTMA surfactant and at less than 3 Å from the Ca2+ ions. In the case of HMP the CrO4−2 ion was mostly located far away from its polar head but located in all cases at less than 3 Å from the Ca2+ ions. In summary, we have found that configurations that showed best adsorption results corresponded to the systems where the contaminant was closer to the polar head of the HDTMA surfactant.

Keywords: calcium montmorillonite; metropolis Monte Carlo; montmorillonite clay modifiers; chromate removal; hexadecyltrimethylammonium; HDTMA; alkyl polyglucoside; adsorption sites; nano-montmorillonite; biosurfactants; cationic surfactants; polar head.

DOI: 10.1504/IJECB.2015.073948

International Journal of Experimental and Computational Biomechanics, 2015 Vol.3 No.3, pp.218 - 235

Received: 03 Sep 2014
Accepted: 21 Aug 2015

Published online: 30 Dec 2015 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article