Exploring the effect of the O-(1-heptylnonyl) benzene sulfonate surfactant on the nature of the linear hydrocarbons/water interface by means of an atomistic molecular dynamics simulation

Issue title: V Congress of Theoretical and Computational Physical Chemistry, 8-10 of December of 2014, Altos de Pipe, Caracas, Venezuela

Guest editors: Fernando Ruette, Anibal Sierralta, Morella Sánchez and Ney Luiggi

Article type: Research Article

Authors: Aray, Yosslen^{a; b; d; *} | Parra, José Gregorio^c | Jiménez, Doris Marianela^a | Paredes, Ricardo^e | Martiz, Alejandro^d | Samaniego, Samantha^f | Cornejo, Mauricio^d | Ludena, Eduardo V.^{a; d} | Paredes, Cecilia^d

Affiliations: [a] Laboratorio de Fisicoquímica Teórica de Materiales, Centro de Química, Instituto Venezolano de Investigaciones Científicas, IVIC, Caracas, Venezuela | [b] Facultad de Ciencias, Universidad de Ciencias Aplicadas y Ambientales, UDCA, Campus Universitario Norte, Bogotá, Colombia | [c] Laboratorio de Química Computacional, Dpto. de Química, Facultad Experimental de Ciencias y Tecnología, Universidad de Carabobo, Edo. Carabobo, Venezuela | [d] Facultad de Ingeniería Mecánica y Ciencias de la Producción, Escuela Superior Politécnica del Litoral, ESPOL, Guayaquil, Ecuador | [e] Facultad de Ingeniería en Ciencias de la Tierra, ESPOL, Campus Gustavo Galindo, Guayaquil, Ecuador | [f] Departamento de Quimica, Facultad de Ciencias Naturales y Matemática, ESPOL, Campus Gustavo Galindo, Guayaquil, Ecuador

Correspondence: [*] Corresponding author: Yosslen Aray, Facultad de Ciencias, Universidad de Ciencias Aplicadas y Ambientales, UDCA, Campus Universitario Norte, Calle 222 No 55-37, Bogotá, Colombia. Tel.: +571 6684700; E-mail:yaray@udca.edu.co

Abstract: Using molecular dynamics simulations a systematic study of the binding energy per cross sectional area for the water/n-alkane (hexane, octane, decane, dodecane and tetradecane) interfaces was performed. The effect of the Sodium p-(1-heptylnonyl) benzene sulfonate surfactant, on the adhesion forces of the water/n-hydrocarbon (decane, undecane, dodecane, and tetradecane) interfaces was studied. Scanning of the binding energy per area against n-alkanes shows that the magnitude of this parameter for the surfactant tail-alkane interactions at the interface systematically increases with the chain length of the alkane, whereas it shows a maximum at undecane for the water-surfactant head interactions at the interface. This maximum of head adhesion forces thus agrees with the reported minimum value of the interfacial tension at undecane for the p-(1-heptylnonyl) benzene sulfonate, suggests that for the water/alkane interface it is this trend in surfactant head adhesion at the interface that defines that interfacial tension minimum value.

Keywords: Linear alkyl benzene sulfonates, molecular dynamics, hydrocarbon water interface, binding energies per area

DOI: 10.3233/JCM-160659

Journal: Journal of Computational Methods in Sciences and Engineering, vol. 17, no. 1, pp. 39-53, 2017