José G. Parra

José G. Parra
Universidad de Carabobo, UC · Department of Chemistry (FACYT)

PhD in Chemistry
Evaluating interfacial properties of systems prepared with surfactants by means of MD simulations.

About

35
Publications
15,884
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98
Citations
Introduction
Actually, I am studying complex systems where are present surfactants,water and oil. I am working with molecular dynamics using gromacs and quantum mechanics with gamess-us and orca. Also, I am determining interfacial properties of systems using experimental techniques.
Additional affiliations
February 2018 - March 2018
Universidad Nacional Autónoma de México
Position
  • Pasantía de investigación
July 2017 - present
Universidad de Carabobo, UC
Position
  • Professor (Associate)
July 2011 - August 2011
Venezuelan Institute for Scientific Research
Position
  • investigador colaborador
Education
October 2011 - October 2016
Central University of Venezuela
Field of study
  • Química
October 1997 - December 2002
Universidad de Carabobo, UC
Field of study
  • Licenciado en Quimica

Publications

Publications (35)
Article
An experimental and computational study, using a Density Functional Theory approach, was made about the anticorrosive effect of ionic liquids on hematite surfaces. Based on the hypothesis that adsorption is an initial step in the kinetics of corrosion, followed by electron transfer processes, adsorption energy calculations and corrosion rates are d...
Poster
Full-text available
Muricatacin is a molecule found in nature, which was discovered when it was isolated from the seeds of the Annona muricata L. (Annonaceae) commonly known as ‘sour sop’ or ‘guanabana’ and recently has been under investigation due to exhibiting potent cytotoxicity towards several human tumor cell lines compared with normal cell lines. Molecular dynam...
Poster
Full-text available
Muricatacin is a natural product that form part of the annonaceous acetogenins derivatives extracted from the seeds of Annona Muricata. Molecular aggregation of this specie as function of the number of molecules in aqueous solution was evaluated by means of MD simulations using the NPT ensemble and CHARMM36 and TIP3P force fields. In this study, sp...
Poster
Full-text available
Hydrogen bonds are one of the most important non-covalent interactions in chemistry, in this sense, the evaluation of the presence of hydrogen bonds is very important. In this work, we explore the nature of the hydrogen bonds in five organic compounds with pharmaceutical applications using the Atoms in Molecules (AIM) theory to explore the strength...
Article
Full-text available
Molecular dynamics is a very useful tool for studying complex systems and determining properties of liquids that are immiscible with each other. In this work, a computational procedure is presented using the GROMACS-4.5.4 program, which was used in a physicochemical laboratory, to estimate the interfacial tension and the interfacial film thickness...
Poster
Full-text available
Malonic acid is considered one of the most abundant dicarboxylic acids present in the atmosphere. Thermal decomposition of this acid produce the acetic acid and CO 2 gas that represent a specie highly contaminant for the air. In this work, the thermal decomposition reaction in the gas phase of the malonic acid was evaluated using quantum-chemical c...
Poster
Full-text available
Carbon 13 chemical shifts of benzoic acid were computationally predicted using the ORCA v4.2.1 package with the PBE, VWN5, B3-LYP, BP86 functionals and the base assemblies 6- 31G(d), 6-31G(d,p), 6-31+G(d,p), 6-31+G(2d,2p), 6-31++G(2d,2p), 6-31++G(2df,2p). Each functional was evaluated for prediction, being the functional VWN5 and B3-LYP the best re...
Article
Molecular dynamics simulations were carried out to investigate the effect of TX-100 surfactant on the interfacial activity of ionic surfactants SDS, CTAB and SDBS at the air/water interface. Here, interfacial properties, molecular orientation of hydrocarbon chains of ionic surfactant and radial distribution functions between hydrophilic headgroups...
Article
Full-text available
The nature of the interaction between the molecules of the sodium dodecyl sulfate surfactant forming two crystal phases, one anhydrous, NaC12H25O4S and the other, NaC12H25O4S.H2O, hydrated with one water molecule for unit cell, has been studied in detail using the quantum theory of atoms in molecules and a localized electron detector function. It w...
Article
Structural characteristics, interfacial distribution and molecular interactions of the components of the CO2(gas)/SDS/water/SDS/CO2(gas) systems as a function of the CO2(gas)/water interface coverage by the SDS surfactant to different amounts of the CO2 were studied with molecular dynamics simulations and the NVT ensemble. Initially, the repulsive...
Article
Interface Interfacial properties of water/SDS+1-butanol/n-octane and water/SDS+2-butanol/n-octane systems have been determined using MD simulations with the aim of studying the molecular interactions between alcohols and SDS when are located at the water/n-octane interface. Also, interfacial properties of water/1-butanol/n-octane, water/2-butanol/n...
Article
Full-text available
En este trabajo, la distribución de las moléculas de 1-butanol y 2-butanol en los sistemas agua/n-octano y agua/SDS/n-octano fue determinada usando las herramientas gmx-density y gmx-densmap del programa gromacs con la finalidad de complementar a nivel computacional el comportamiento experimental estos co-surfactantes cuando están localizados en la...
Poster
Full-text available
In Venezuela, Acevedo et al. proposed asphaltene models (A1 and A2 fractions) for crude oil with the aim of explaining the difference in found experimental solubility in n-heptane and toluene. However, its behavior and preference for certain interfacial regions was not studied. In the present work, we studied the preferential affinity of these asph...
Article
The Nudged Elastic Band (NEB) method is an algorithm to search the minimum energy path (MEP), which has been successfully applied for studying several processes that involve solid-state models; however, it has not been widely tested in discrete molecular systems. Performing density functional theory calculations, this method was employed in NWChem...
Article
Full-text available
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, dodec...
Article
Full-text available
En este trabajo, usando dinámica molecular se determinaron las propiedades interfaciales y el comportamiento del Dodecil Sulfato de Sodio (SDS) ubicado en la región interfacial de los sistemas vacío/agua y agua/n-octano. La tensión interfacial fue estimada con el modelo propuesto por Kirkwood y Buff [23]. A su vez, los espesores de película interfa...
Thesis
Full-text available
En el presente trabajo, se estudió el efecto de la serie de surfactantes triton sobre las propiedades interfaciales (tensión interfacial, espesor de película, perfil de densidad y las energías de formación de interfaz) en el sistema dodecilsulfato de sodio/agua mediante la técnica dinámica molecular para ello se empleó el software GROMACS 4.5.6. Ut...
Thesis
Full-text available
Se estudió la agregación de una fracción de asfaltenos A1 en las regiones interfaciales de los sistemas Agua/A1/Tolueno y Agua/A1/n-heptano, por medio de las propiedades interfaciales (perfil de densidad y tensión superficial), de la función de distribución radial, cluster formados y mínima distancia entre agregados, mediante la técnica de dinámica...
Poster
Full-text available
Los asfaltenos corresponden a ciertos compuestos poliaromáticos de alto peso molecular presentes en diferentes tipos de crudos, residuos del petróleo y bitúmenes. Estas especies son consideradas compuestos polares conformados por estructuras poliaromáticas condensadas que contienen cadenas alifáticas, ciertos metales de transición (Niquel y Vanadio...
Poster
Full-text available
RESUMEN Los asfaltenos corresponden a ciertos compuestos poliaromáticos de alto peso molecular presentes en diferentes tipos de crudos, residuos del petróleo y bitúmenes. Estas especies son consideradas compuestos polares conformados por estructuras poliaromáticas condensadas que contienen cadenas alifáticas, ciertos metales de transición (Níquel y...
Article
Full-text available
Macroscopic interfacial properties (film thickness, interfacial tension and concentration) of the n-hexane/water, cyclohexane/water, toluene/water, water/1-butanol/hydrocarbons and water/2-butanol/hydrocarbons systems have been estimated through molecular dynamics simulations by using Gromacs 4.5.4 software. SPC, SPC-E and OPLS-AA potential energy...
Conference Paper
Full-text available
Correo Electrónico: jgparra2@uc.edu.ve,yaray@ivic.gob.ve RESUMEN En este trabajo, se determinaron los espesores de película interfacial, las tensiones interfaciales y las energías de formación de la interface de los sistemas vacío/agua/SDS/pentanol/vacío y vacío/agua/SDS/hexanol/vacío usando dinámica molecular clásica tipo NVT. Las moléculas de SD...
Conference Paper
Full-text available
RESUMEN Debido al gran uso que tiene el amino-G como marcador para la determinación de contaminantes en agua, en este trabajo, se estudio las interacciones entre el amino-G y el agua usando dinámica molecular clásica tipo NVT y NPT. Para ello, la molécula de amino-G fue descrita usando el modelo de energía potencial GROMOS-53A6 y las moléculas de...
Article
Full-text available
Using molecular dynamics simulations type NVT to 300 K with the program Gromacs-4.5.5, the interfacial thicknesses and orientation of water in the interfacial region of the water/1-pentanol, water/1-hexanol system were determined. In turn, the effect of the Sodium Dodecyl Sulfate (SDS) on interfacial properties of these systems was studied with the...
Conference Paper
Full-text available
En este trabajo, se correlaciona la solubilidad experimental del naftaleno en 1-butanol, acetato de etilo, acetato de isobutilo, acetona, ácido n-butanoico, etanol, n-heptano, N,N-dimetil formamida, THF, tolueno e isómeros de xileno a 298.15K, con las energías de interacción de dímeros naftaleno/disolvente obtenidas con el método fragmento efectivo...
Thesis
Full-text available
En este trabajo se obtuvo una correlación entre la solubilidad experimental del naftaleno en diversos disolventes orgánicos, con las energías de interacción obtenidas con el método EFP contenido en el programa GAMESS-US. A su vez, se estudio la interacción del naftaleno con los diferentes disolventes usando el método Morokuma, LMOEDA, QM/MM y optim...
Article
Full-text available
The solubility parameters, δ, of several asphaltene models were calculated by mean of an atomistic NPT ensemble. Continental and archipelago models were explored. A relationship between the solubility parameter and the molecule structure was determined. In general, increase of the fused-rings number forming the aromatic core and the numbers of hete...
Article
Full-text available
Usando el método de solvatación del modelo de apantallamiento tipo conductor (COSMO) y el método de Amovilli-Mennucci contenido en el programa GAMESS, se estimaron las energías libres de Van der Waals y electrostáticas de moléculas orgánicas en su propio medio dieléctrico. Con estas energías y el volumen de la cavidad del soluto, se diseñaron dos m...
Article
Full-text available
For 21 organic liquids, free nonbonding energies were calculated in their dielectric medium using the methods Conductor Polarizable Continuum Model (C-PCM) and Conductor-like Screening Model (COSMO) to RHF/6-31G (2p, 2d) and DFT// PBE-VWN5/6-31G (2p, 2d) levels and the free energies of dispersion and repulsion using the Amovilli-Mennucci method. Wi...
Article
Full-text available
El parámetro de solubilidad y la densidad de compuestos orgánicos y modelos de fracciones de asfaltenos propuestos para el crudo Furrial fue determinado utilizando la técnica de dinámica molecular. Con el valor del parámetro de solubilidad estimado para estos modelos de fracciones de asfaltenos y ciertos solventes orgánicos, se establecen los facto...
Technical Report
Full-text available
Este es un borrador sobre el estudio del comportamiento de cadenas cortas de polióxido de etileno en agua usando dinámica mesoscópica.

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Projects

Projects (11)
Project
Evaluation of organic compounds using the Quantum Theory Atoms in Molecules
Project
In this project, I am evaluating the interactions and effect of natural surfactants with biomembranes