Propiedades interfaciales y equilibrio de fase de mezclas fluidas mediante simulación Monte Carlo

Martínez Ruiz, Francisco José

Dirigida por: Felipe Jiménez Blas Director

Universidad de defensa: Universidad de Huelva

Fecha de defensa: 30 de noviembre de 2015

Resumen

The understanding, from a molecular perspective, of the phase equilibria and interfacial properties of condensed systems, has increased in the last years. However, the determination of the thermodynamic and structural properties of inhomogeneous systems of complex mixtures (molecular chains, associating systems...), such as the interfacial thickness, adsorption, and surface tension, among others, is limited compared with that of homogenous systems. The precise knowledge of the interfacial properties is essential from a theoretical point of view and for the design of process of industrial interest. Nowadays, it is possible to determine the global phase diagram and the interfacial properties of a given model using molecular simulation. This is probably due to the enormous increasing of the available computational resources and also due to the development of new and more effective computational methods during the last years.

 In this Thesis, we combine different Monte Carlo simulation techniques to understand, from the Statistical Mechanics point of view, how the microscopic parameters of a given molecular model determine the interfacial properties of systems that exhibit vapour-liquid and liquid-liquid equilibria. The analysis on how the long-range corrections affect the behaviour of the system, particularly due to the discontinuities existing in continuous potential that are truncated at a given distance, is an important and delicate issue. In this Thesis, we extend and improve an existing methodology in the literature to account for these long-range corrections. We put special emphasis on how these corrections affect to the interfacial tension and extend and improve the standard method for determining the pressure tensor in inhomogeneous systems (virial or mechanical route). This methodology is easy to apply and implement in systems form from spherically symmetric molecules, but this is not the case of complex molecular systems. In this Thesis, we use alternative methods, based on the thermodynamic route, such as the volume perturbation technique, the Test-Area (TA) methodology, and the Wandering Interface Method (WIM).

We have determined the vapour-liquid and liquid-liquid interfacial tension of binary mixtures of spherical systems, and the vapour-liquid surface tension of flexible chainsform from monomers that interact through the Lennard- Jones and Square-Well intermolecular potentials, among many other interfacial properties. The Soft-SAFT approach, based on Wertheim’s theory, is used to calculate the global phase diagram of the mixtures studied in order to compare the simulation results obtained in this Thesis. In the case of flexible Lennard-Jones chains, we have studied the effect of chain length and flexibility on the phase equilibria and interfacial properties. We have also calculated the vapour pressure of Square-Well chains along the vapour-liquid coexistence combining Monte Carlo simulations of the interface and the thermodynamic integration technique, as well as the associated error from the Sinthetic Method. Finally, we have also analysed some universal scaling relationships for Lennard-Jones and Square-Well molecular chains with different degrees of flexibility.

Vapor-liquid interfacial properties of square-well chains from density functional theory and Monte Carlo simulation. Physical Chemistry Chemical Physics Año: 2017 Volumen: 19 Página inicial: 12296 Página final: 12309 Autores: Martínez-Ruiz, Francisco José; Jimenez-Blas, Felipe; Moreno-Ventas-Bravo, A. Ignacio; Míguez, Jose Manuel; González-Macdowell, Luis.

Interfacial properties of binary mixtures of square-well molecules from Monte Carlo simulation. The Journal of Chemical Physics Año: 2016 Volumen: 144 Número: 15 Página inicial: 154705-1 Página final: 154705-10 Autores: Martínez-Ruiz, Francisco José; Jimenez-Blas, Felipe.

Determination of interfacial tension of binary mixtures from perfturbative approaches. Molecular Physics Año: 2015 Volumen: 113 Número: 9-10 Página inicial: 1217 Página final: 1227 Autores: Martínez-Ruiz, Francisco José; Jimenez-Blas, Felipe 

Liquid-liquid interfacial properties of a symmetrical Lennard-Jones binary mixture The Journal of Chemical Physics Año: 2015 Volumen: 143 Número: 10 Página inicial: 104706-1 Página final: 104706-11 Autores: Martínez-Ruiz, Francisco José; Moreno-Ventas-Bravo, A. Ignacio; Jimenez-Blas, Felipe.

Effect of molecular flexibility of Lennard-Jones chains on the vapor-liquid interfacial properties. The Journal of Chemical Physics Año: 2014 Volumen: 140 Número: 11 Página inicial: 114705-1 Página final: 114705-11 Autores: Jimenez-Blas, Felipe; Moreno-Ventas-Bravo, A. Ignacio; Algaba-Fernández, Jesús; MartínezRuiz, Francisco José; Gonzalez-macdowell, Luis.

Effect of dispersive long-range corrections to the pressure tensor: The vapor-liquiid interfacial properties of Lennard-Jones system revisited. The Journal of Chemical Physics Año: 2014 Volumen: 141 Número: 18 Página inicial: 184701-1 Página final: 184701-17 Autores: Martínez-Ruiz, Francisco José; Jimenez-Blas, Felipe; Mendiboure-, Bruno; Moreno-VentasBravo, A. Ignacio.

Universal scaling behaviour of surface tension of molecular chains. The Journal of Chemical Physics Año: 2012 Volumen: 137 Página inicial: 24702 Página final: 24702 Autores: Jimenez-Blas, Felipe; Martínez-Ruiz, Francisco José; Moreno-Ventas-Bravo, A. Ignacio; González-Macdowell, Luis.

An efficiency calibration for 210Pb and 7Be measurements by gamma-ray spectrometry in atmospheric filters. Nuclear Instruments and Methods in Physics Research A 580 (2007) 663–666. F. Martínez-Ruiz, E. Borrego, E.G. San Miguel , J.P. Bolıivar,.

AN EFFICIENCY CALIBRATION FOR 210PB AND 7BE MEASUREMENTS BY GAMMA-RAY SPECTROMETRY IN ATMOSPHERIC FILTERS: PROCEEDINGS OF THE 10 TH INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS - ISRP 10. Applied Radiation and Isotopes Año: 2007 Volumen: 580 Número: 1 Página inicial: 663 Página final: 666 Autores: Martínez-Ruiz, Francisco José; Borrego-Flores, Esther; Bolívar-Raya, Juan Pedro. Universidad 29/03/2025 FRANCISCO JOSÉ MARTÍNEZ RUIZ 6 / 7 de Huelva. Física Aplicada 

Trabajo conducente a obtención de DEA

Autor: Martínez-Ruiz, Francisco José. 

Título: RADIACTIVIDAD EN AEROSOLES ATMOSFÉRICOS DE LA PROVINCIA DE HUELVA

Director: Bolívar-Raya, Juan Pedro;Gutiérrez De San Miguel-Herrera, Enrique

Universidad: Universidad de Huelva. Facultad de Ciencias Experimentales

Fecha de lectura: 02/12/2005