Article
Chemistry, Physical
Nicolas Carro, Andres Mejia
Summary: The influence of droplet geometry on the interfacial tension of aliphatic hydrocarbons + water mixtures is studied using the square gradient theory of van der Waals in cylindrical and spherical geometries. Density profiles fail to converge to the equilibrium values at the bulk limit under a lower critical radius, resulting in a steeper and irregular curve. To avoid this issue, calculations are conducted within a consistent range where the radius dependency of interfacial tension is negligible. Since determining the radius of tension is still controversial, a zeroth-order approximation is used for choosing the dividing surface based on the Gibbs dividing surface. The theoretical results are qualitatively compared with molecular dynamics calculations to validate the predicted trend by the model.
Article
Thermodynamics
Ahmed AlYazidi, Luis F. M. Franco, Ioannis G. Economou, Marcelo Castier
Summary: The SAFT-VR Mie equation of state, Dubinin-Radushkevich-Astakhov (DRA) potential, and Steele potential were utilized to model the thermodynamic behavior of fluids confined in porous media. The results showed a strong agreement with experimental data for various adsorption systems.
FLUID PHASE EQUILIBRIA
(2021)
Article
Multidisciplinary Sciences
Dengpan Ma, Paerhatijiang Tuersun, Long Cheng, Yuxia Zheng, Remilai Abulaiti
Summary: This paper introduces PyMieLab, a software based on Mie theory for calculating the light scattering and absorption of spherical particles. The software is interactive, versatile, visual, flexible, and scalable, making it a reliable research platform for scientific simulations.
Article
Chemistry, Physical
Cara E. Schwarz, Sonja A. M. Smith
Summary: This study presents high-pressure phase transition data for various CO2 + saturated fatty acid methyl ester systems using a visual static synthetic method. The newly measured data complements previously published data and covers a wide range of methyl esters. The results show that the systems studied do not exhibit three-phase behavior or temperature inversions, and the phase transition pressure increases with temperature and molecular mass of the methyl ester. The SAFT-VR Mie equation of state correlates well with the data, but with decreasing performance at higher methyl ester molecular masses and lower temperatures.
JOURNAL OF SUPERCRITICAL FLUIDS
(2023)
Article
Thermodynamics
R. Villablanca-Ahues, R. Nagl, T. Zeiner, P. Jaeger
Summary: This study investigates and predicts the interfacial tension at elevated pressure for binary systems, which are crucial for the ongoing energy transition. A comprehensive review is conducted on saturated mixture densities and interfacial tension in binary, ternary, and quaternary systems containing nonpolar and polar compounds at elevated pressures. New experimental and theoretical data on binary systems are presented to fill the research gap, especially for quaternary model systems containing H2O, a hydrocarbon, a gas, and a surface-active compound. The experimental results are in good agreement with simulations and previously available data, showing an absolute average deviation ranging from 0.44 mN/m to 2.58 mN/m.
FLUID PHASE EQUILIBRIA
(2023)
Article
Chemistry, Physical
Ismail I. I. Alkhatib, Lourdes F. Vega
Summary: In this study, polar soft-SAFT theory was used to analyze the influence of polar interactions on binary mixtures, showing that the type and strength of polar interactions directly affect vapor-liquid equilibrium and that increasing polar strength can make the equilibrium more ideal. The study also examined interfacial properties and found distinct enrichment in mixtures with highly quadrupolar fluids.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Yafan Yang, Arun Kumar Narayanan Nair, Weiwei Zhu, Shuxun Sang, Shuyu Sun
Summary: Molecular dynamics simulations were used to investigate the interfacial properties of H2+H2O and H2+H2O+silica/kerogen systems. The results showed that the combination of the H2 model with the INTERFACE force field and TIP4P/2005 H2O model accurately predicted the experimental interfacial tensions of the H2+H2O mixture. This study provides important insights for the underground storage and utilization of H2 in the environment.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Thermodynamics
Yunhao Sun, Zhida Zuo, Gulou Shen, Christoph Held, Xiaohua Lu, Xiaoyan Ji
Summary: The ePC-SAFT-DGT model was further refined by modifying the expression for estimating the chemical potential of IL ion-pair, allowing for reliable representation of IL surface tension. Anion-specific influence parameters enabled semi-prediction of surface tension for ILs in the same homologous series.
FLUID PHASE EQUILIBRIA
(2021)
Article
Energy & Fuels
Yanling Gao, Keliu Wu, Zhangxin Chen, Weibing Tian, Jing Li, Ziyang Huang, Jianfei Bi
Summary: This study proposes a simple model for describing the density profile of nanoconfined fluids at the interface, estimating the confined interfacial properties and phase behavior based on the density distribution model and state equation, and discussing the effects of temperature, pore size, and wettability on interfacial tension and capillarity. Validation with experimental data demonstrates the reliability of the model for interfacial tension calculation.
Article
Environmental Sciences
Yafan Yang, Weiwei Zhu, Yukun Ji, Tao Wang, Guangsi Zhao
Summary: The interfacial properties of H2O+CO2+oil three-phase systems are important for CO2 flooding and sequestration processes. The interfacial tension of the aqueous phase+vapor phase in these systems is smaller than that in H2O+CO2 two-phase systems due to oil enrichment in the interface. The difference in interfacial tension between the three-phase system and the H2O+CO2 two-phase system is largest in the benzene case and smallest in the cyclohexane case. CO2 enrichment in the interfacial region of the aqueous phase+oil-rich phase leads to a reduction in interfacial tension with increasing pressure.
Article
Chemistry, Physical
Morten Hammer, Gernot Bauer, Rolf Stierle, Joachim Gross, Oivind Wilhelmsen
Summary: We propose a classical density functional theory (DFT) based on a third-order thermodynamic perturbation theory of Feynman-Hibbs-corrected Mie potentials for studying the interfacial properties of fluid mixtures influenced by quantum effects. The DFT accurately predicts the radial distribution function of pure components and mixtures, and the surface tensions of different fluids with good accuracy at temperatures above 20 K. However, below 20 K, the accuracy decreases due to limitations of the Feynman-Hibbs-corrected Mie potentials. The DFT can be used for studying confined fluids and evaluating porous materials for hydrogen storage and transport.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Aristotelis P. Sgouros, Constantinos J. Revelas, Apostolos T. Lakkas, Doros N. Theodorou
Summary: Predicting the distribution of a chemical species in different phases is crucial for environmental protection, pharmaceuticals, and high added-value chemicals. This study develops a theoretical framework to determine the solvation free energy of grafted particles in a molten polymer matrix, which can be used to estimate their partition coefficients in polymer melts.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Thermodynamics
Ziqing Pan, J. P. Martin Trusler
Summary: Experimental interfacial tensions (IFTs) of CO2 and decane-iododecane mixtures were measured over a wide range of temperatures and pressures. The volume of the hydrocarbon drop initially increased while the IFT decreased before reaching equilibrium values. These observations are significant for understanding the mechanisms of CO2 flooding.
FLUID PHASE EQUILIBRIA
(2023)
Article
Engineering, Chemical
Yunhao Sun, Xian Tang, Xiaoyan Ji, Xiaohua Lu, Xiang Ling
Summary: In this work, the DGT-PC-SAFT model was used to calculate the interfacial transport resistivities at the vapor-liquid interface. By combining the general approach with the Chebyshev spectral collocation method, a stable and efficient method was developed to solve the density profile using density gradient theory (DGT). It was found that using a suitable conformal map in the Chebyshev spectral collocation method could reduce the required collocation points for the calculation of interfacial transport resistivities significantly. Interfacial transport resistivities of n-alkane/nitrogen mixtures were predicted using the developed algorithm, revealing a certain deviation compared to those calculated with DFT-PC-SAFT, and the reason for this deviation was discussed in this paper.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Proceedings Paper
Computer Science, Information Systems
Mateja Milic, Nenad Buncic
Summary: This paper addresses the issue of using digital image processing algorithms on embedded processors, focusing on edge detection of images and videos. The implementation involves calculating the magnitude and angle of an image gradient, crucial for edge detection. By combining software implementation with specific hardware accelerators in FPGA, the system's processing speed is significantly improved.
2021 29TH TELECOMMUNICATIONS FORUM (TELFOR)
(2021)
Article
Thermodynamics
Andres Mejia, Marcela Cartes, Alejandra Velasquez
Summary: Experimental measurements of vapor-liquid equilibrium and interfacial tension for the 1-propanol + cyclopentyl methyl ether binary mixture have been conducted across the entire mole fraction range. The binary mixture exhibits positive deviation in vapor-liquid equilibrium and displays a decrease in interfacial tension with increasing 1-propanol liquid mole fraction.
JOURNAL OF CHEMICAL THERMODYNAMICS
(2021)
Article
Chemistry, Physical
Carlos Morales-Diaz, Adolfo L. Cabrera, Juan C. de la Fuente, Andres Mejia
Summary: The study applied state equations to investigate the solubility of vitamin K-3 derivatives in supercritical carbon dioxide, using group contribution methods to estimate thermophysical properties. It was found that the solubility prediction from the SAFT-VR Mie model showed the best performance among all equations of state.
JOURNAL OF SUPERCRITICAL FLUIDS
(2021)
Article
Energy & Fuels
Marcela Cartes, Gustavo Chaparro, Andres Mejia
Summary: This study investigates the phase equilibria of ternary and binary mixtures at specific conditions, showing positive deviation from Raoult's law and zeotropic behavior. Experimental data and theoretical models suggest different capabilities in predicting the phase equilibrium of mixtures.
Article
Thermodynamics
Andres Mejia, Marcela Cartes, Alejandra Velasquez
Summary: This experimental work investigates the phase equilibria, surface tension, and liquid dynamic viscosity of the propan-1-ol + dibutyl ether binary mixture at different pressures and temperatures, revealing a positive deviation and the presence of a minimum temperature azeotrope. The surface tension and liquid dynamic viscosity of the binary mixture increase with the mole fraction of propan-1-ol.
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2021)
Article
Chemistry, Physical
Andres Mejia, Marcela Cartes, Gustavo Chaparro, Esther Feria, Felipe J. Blas, Jose Manuel Miguez, Jesus Algaba, Erich A. Mueller
Summary: Experimental determination, theoretical modeling, and molecular simulation have been combined to describe the bulk phase equilibria and interfacial properties for methane + n-hexadecane, n-dodecane, n-tetradecane and n-hexadecane binary mixtures at 344.15 K and in a pressure range between 0.1 and 30 MPa. The three approaches are able to independently predict phase equilibrium and interfacial properties and show a very good agreement amongst themselves.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Engineering, Chemical
Gonzalo R. Quezada, Andres Mejia, Eder Piceros, Pedro Robles, Steven Nieto, Edelmira Galvez, Ricardo I. Jeldres
Summary: The study evaluates the adsorption capacity of sodium triphosphate in kaolinite using theoretical molecular approach combining quantum calculations and molecular dynamics simulation. It was found that triphosphate can self-aggregate, especially in saline solutions, and form stable sodium-mediated bridge-type interactions on kaolinite surfaces.
MINERALS ENGINEERING
(2022)
Article
Chemistry, Physical
Esther Feria, Jesus Algaba, Jose Manuel Miguez, Andres Mejia, Felipe J. Blas
Summary: In this research, the liquid-liquid phase equilibria and interfacial properties of methyl ester + water binary mixtures have been studied using molecular dynamics simulations and the direct coexistence technique. The simulation results are in good agreement with experimental data for phase equilibria, but overestimate the interfacial tensions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Nicolas Carro, Andres Mejia
Summary: The influence of droplet geometry on the interfacial tension of aliphatic hydrocarbons + water mixtures is studied using the square gradient theory of van der Waals in cylindrical and spherical geometries. Density profiles fail to converge to the equilibrium values at the bulk limit under a lower critical radius, resulting in a steeper and irregular curve. To avoid this issue, calculations are conducted within a consistent range where the radius dependency of interfacial tension is negligible. Since determining the radius of tension is still controversial, a zeroth-order approximation is used for choosing the dividing surface based on the Gibbs dividing surface. The theoretical results are qualitatively compared with molecular dynamics calculations to validate the predicted trend by the model.
Article
Thermodynamics
Andres Mejia, Marcela Cartes, Alejandra Velasquez, Gustavo Chaparro, Vilma Sanhueza
Summary: This study measures and theoretically predicts the bulk, transport, and surface properties of the n-hexane cyclopentyl methyl ether + 1-butanol ternary mixture. The experimental data are well correlated with the theoretical predictions, indicating good agreement between them.
FLUID PHASE EQUILIBRIA
(2022)
Article
Chemistry, Physical
Marcela Cartes, Gustavo Chaparro, Gerard Alonso, Andres Mejia
Summary: Experimental determination, theoretical modeling, and molecular simulation were used to study the density and viscosity of liquid substances. The experimental results showed that the density and viscosity of pure liquids decrease with temperature. In liquid mixtures, both density and viscosity deviate negatively from the linear trend. The theoretical models can accurately predict the density and viscosity of binary and ternary mixtures. Molecular simulation accurately describes the density but has some deviations in viscosity predictions.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Thermodynamics
Simon Stephan, Harry Cardenas, Andres Mejia, Erich A. Mueller
Summary: This article revisits the description of density profiles at the vapor-liquid interface of mixtures in the seminal monograph 'Molecular Theory of Capillarity' by Rowlinson and Widom. It summarizes the different suggested morphologies at the interface and acknowledges the absence of reports on profiles with a single minimum. Both profiles with a single maximum and fully monotonic profiles have been extensively observed and reported. The presence of both a maximum and a minimum in the density profiles is controversial and has only been predicted using theoretical approaches like density gradient theory (DGT). This study investigates this ambiguity using the example of the vapor-liquid interface of cyclohexane + butanol, employing DGT and molecular dynamics simulations. The results from the two methods contradict each other, with DGT predicting a maximum/minimum structure while the computer experiment results show only a single maximum. Thus, this work highlights the need for caution when interpreting DGT results for highly non-ideal mixtures.
FLUID PHASE EQUILIBRIA
(2023)
