1,672 results on '"Vapor liquid"'
Search Results
52. Vapor–Liquid Equilibria of the Aqueous and Organic Mixtures Composed of Dipropylene Glycol Methyl Ether, Dipropylene Glycol n -Butyl Ether, and Propylene Glycol n -Butyl Ether. Part II: Modeling Based on the NRTL-PR Model
- Author
-
Evelyne Neau, Pierrette Guichardon, Oleksandr Dimitrov, Isabelle Raspo, Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Aqueous solution ,glycol ether ,Chemistry ,General Chemical Engineering ,Ether ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Polyvinyl alcohol ,Industrial and Manufacturing Engineering ,NRTL-PR model ,0104 chemical sciences ,Vapor-liquid equilibria ,chemistry.chemical_compound ,020401 chemical engineering ,Non-random two-liquid model ,Dipropylene glycol ,[SPI.MECA.THER]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph] ,Organic chemistry ,Vapor liquid ,[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] ,0204 chemical engineering ,Dipropylene glycol methyl ether - Abstract
International audience; Further to the Part I of the present paper, the second Part is concentrated around the VLE modeling of binary mixtures involving the three glycol ethers previously studied experimentally. The authors propose to use the NRTL-PR model for the representation of these non-ideal mixtures. The main difficulties of modelling related to very low vapor pressures and the way of dealing with them are highlighted. The unknown critical parameters for DPM, DPnB and PnB were determined using robust group contribution methods. However, the experimental values of these parameters have never been published before. The main goal of the authors was to obtain the most satisfactory representation of the experimental data provided in the Part I. Some issues that mostly occurred in mixtures involving the PnB as well as in mixtures having very low vapor pressures, were encountered. Nevertheless, we have obtained in general a satisfactory representation of measured points regardless of those issues.
- Published
- 2021
53. Interatomic Interactions Responsible for the Solid-Liquid and Vapor-Liquid Phase Equilibria of Neon
- Author
-
Richard J. Sadus and Ulrich K. Deiters
- Subjects
Materials science ,Ab initio ,chemistry.chemical_element ,Thermodynamics ,Molecular simulation ,Surfaces, Coatings and Films ,Degree (temperature) ,Neon ,chemistry ,Phase (matter) ,Materials Chemistry ,Vapor liquid ,Physical and Theoretical Chemistry ,Quantum ,Solid liquid - Abstract
The role of interatomic interactions on the solid-liquid and vapor-liquid equilibria of neon is investigated via molecular simulation using a combination of two-body ab initio, three-body, and quantum potentials. A new molecular simulation approach for determining phase equilibria is also reported and a comparison is made with the available experimental data. The combination of two-body plus quantum influences has the greatest overall impact on the accuracy of the prediction of solid-liquid equilibria. However, the combination of two-body + three-body + quantum interactions is required to approach an experimental accuracy for solid-liquid equilibria, which extends to pressures of tens of GPa. These interactions also combine to predict vapor-liquid equilibria to a very high degree of accuracy, including a very good estimate of the critical properties.
- Published
- 2021
54. Dynamique de consommation de la gouttelette en croissance VLS de nanofils III-V
- Author
-
Andrea Cattoni, Frank Glas, Fabrice Oehler, Anton Pishchagin, Gilles Patriarche, Jean-Christophe Harmand, Centre de Nanosciences et de Nanotechnologies (C2N), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut Photovoltaïque d’Ile-de-France (ITE) (IPVF), and European Project: 722176,H2020, H2020-MSCA-ITN-2016,INDEED(2017)
- Subjects
Materials science ,Dynamics (mechanics) ,Nanowire ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Chemical engineering ,0103 physical sciences ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,General Materials Science ,Vapor liquid ,010306 general physics ,0210 nano-technology - Abstract
International audience; We study experimentally and theoretically the consumption of the apical gallium droplet that mediates the self-catalyzed vapor-liquid-solid growth of GaP nanowires. Consumption is achieved after growth by providing only phosphorous and its progress is monitored ex situ in nanowire arrays fabricated by molecular beam epitaxy. We develop detailed calculations of the process, taking into account four channels of liquid gallium consumption. These include the formation of GaP using phosphorous delivered to the droplet by direct impingement or after re-emission from the substrate. We show that two other channels contribute significantly, namely the diffusion of phosphorous along the sidewalls and gallium back diffusion from the droplet. All currents are calculated analytically as a function of droplet geometry. Complementary experiments are performed to extract the two model parameters governing the diffusion currents. We then compute numerically the dynamics of the system exposed to a constant external phosphorous flux. Our quantitative model allows one to predict how droplet contact angle and radius change while operating blindly in a standard epitaxy chamber. Controlling these parameters is crucial for tailoring the crystal phase of III-V nanowires and fabricating quantum size structures.
- Published
- 2021
55. Vapor–Liquid Equilibria of the Aqueous and Organic Mixtures Composed of Dipropylene Glycol Methyl Ether, Dipropylene Glycol n -Butyl Ether, and Propylene Glycol n -Butyl Ether. Part I: Experimental Study
- Author
-
Ilham Mokbel, Jacques Jose, Pierrette Guichardon, Oleksandr Dimitrov, Fatiha Dergal, Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, and Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)
- Subjects
Aqueous solution ,General Chemical Engineering ,Water ,Ether ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Polyvinyl alcohol ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,[SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph] ,chemistry.chemical_compound ,020401 chemical engineering ,chemistry ,Dipropylene glycol ,Organic chemistry ,Vapor liquid ,0204 chemical engineering ,Dipropylene glycol methyl ether - Abstract
International audience; An experimental and theoretical study was undertaken for three ether glycols (mixtures of isomers). The present paper, being the first part of a complex study, reports the experimental part of the study using a static apparatus, namely, the vapor-liquid equilibria of dipropylene glycol methyl ether (DPM), dipropylene glycol n-butyl ether (DPnB), and propylene glycol n-butyl ether (PnB), and the vapor-liquid equilibria of their pseudo-binary mixtures composed of (PnB + DPM), (DPM + DPnB), (PnB + DPnB), and the aqueous solutions of each ether. The explored temperature range is between 283.15 and 363.15 K. The experimental points were fitted using the Antoine equation. No literature data was found for comparison. The aim of this paper is not only to provide the obtained experimental data but also to highlight the eventual challenges when working with very low vapor pressure compounds and mixtures. The second part is related to a theoretical study with the development of a thermodynamic model for the representation of the experimental data.
- Published
- 2021
56. Dynamics of Monolayer Growth in Vapor–Liquid–Solid GaAs Nanowires Based on Surface Energy Minimization
- Author
-
Hadi Hijazi and Vladimir G. Dubrovskii
- Subjects
vapor–liquid–solid growth ,Materials science ,General Chemical Engineering ,Doping ,Nanowire ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surface energy ,Article ,Crystal ,Chemistry ,nanowires ,Chemical physics ,surface energy ,Phase (matter) ,0103 physical sciences ,Monolayer ,General Materials Science ,Vapor liquid ,monolayer step ,010306 general physics ,0210 nano-technology ,QD1-999 - Abstract
The vapor–liquid–solid growth of III-V nanowires proceeds via the mononuclear regime, where only one island nucleates in each nanowire monolayer. The expansion of the monolayer is governed by the surface energetics depending on the monolayer size. Here, we study theoretically the role of surface energy in determining the monolayer morphology at a given coverage. The optimal monolayer configuration is obtained by minimizing the surface energy at different coverages for a set of energetic constants relevant for GaAs nanowires. In contrast to what has been assumed so far in the growth modeling of III-V nanowires, we find that the monolayer expansion may not be a continuous process. Rather, some portions of the already formed monolayer may dissolve on one of its sides, with simultaneous growth proceeding on the other side. These results are important for fundamental understanding of vapor–liquid–solid growth at the atomic level and have potential impacts on the statistics within the nanowire ensembles, crystal phase, and doping properties of III-V nanowires.
- Published
- 2021
57. Vapor-Liquid Partitioning of Methylmercury Compounds: Fundamental Data to Support the Savannah River Site Liquid Waste System: Henry's Law, Solubility and Vapor Pressure Determination for Representative Methylmercury Compounds
- Author
-
Emily Fabricatore, Holly Vermeulen, Brian B. Looney, J. Dickson, Andrew Boggess, Thomas L. White, and Thomas Peters
- Subjects
Vapor pressure ,Savannah River Site ,Environmental chemistry ,Environmental science ,Vapor liquid ,Liquid waste ,Solubility ,Methylmercury Compounds ,Henry's law - Published
- 2021
58. High-Pressure Vapor–Liquid Equilibria for a CO2 + p-Cymene Binary System at Temperatures from 313.15 to 353.15 K
- Author
-
Yuqi Wang, Zhao Jiang, Songhui Wang, Tao Fang, and Shiyuan Wang
- Subjects
chemistry.chemical_compound ,p-Cymene ,Chemistry ,General Chemical Engineering ,High pressure ,Carbon dioxide ,Analytical chemistry ,Vapor liquid ,General Chemistry ,Binary system - Abstract
High-pressure vapor–liquid equilibrium (VLE) data for the carbon dioxide + p-cymene system at 313.15, 333.15, and 353.15 K and pressures up to 12.0 MPa were measured by a flow-type visualization ap...
- Published
- 2019
59. Isobaric Vapor–Liquid Equilibria of Binary Mixtures of Diethyl Carbonate with Isopropyl Acetate, sec-Butyl Acetate, or Isoamyl Acetate at 101.3 kPa
- Author
-
Yigang Ding, Zhiguo Yan, Hongmei Du, Wenbo Jiang, Zhiping Du, Xia Yin, Jingjing Li, and Chaochen Du
- Subjects
chemistry.chemical_compound ,chemistry ,General Chemical Engineering ,Isoamyl acetate ,Diethyl carbonate ,Isobaric process ,Carbonate ,Vapor liquid ,Organic synthesis ,General Chemistry ,Isopropyl acetate ,sec-Butyl acetate ,Nuclear chemistry - Abstract
Carbonate esters and esters were commonly used as solvents, reaction carrier, and additives in organic synthesis, the pharmaceutical industry, and processing industries. Vapor–liquid equilibrium (V...
- Published
- 2019
60. Assessing the Quality of Molecular Simulations for Vapor–Liquid Equilibria: An Analysis of the TraPPE Database
- Author
-
Robert F. DeJaco, Yangzesheng Sun, Muhammad Ahsan, J. Ilja Siepmann, Becky L. Eggimann, Tyler R. Josephson, and Ramanish Singh
- Subjects
020401 chemical engineering ,Phase equilibrium ,Chemistry ,Robustness (computer science) ,General Chemical Engineering ,Vapor liquid ,02 engineering and technology ,General Chemistry ,Biochemical engineering ,0204 chemical engineering ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences - Abstract
As molecular modeling and simulation techniques become increasingly important sources of thermophysical property and phase equilibrium data, the ability to assess the robustness of that data become...
- Published
- 2019
61. Supplement to Calculating Vapor–Liquid Surface Tension According to Gibbs
- Author
-
Yu. K. Tovbin
- Subjects
Materials science ,Continuum mechanics ,Thermodynamics ,Molecular orbital theory ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Surface tension ,Lattice (order) ,Molecule ,Vapor liquid ,Structural deformation ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
Expressions for calculating Gibbs vapor–liquid surface tension σ are generalized to allow for the interaction between comparable components of a mixture with an arbitrary radius of the interaction potential. Calculations are performed within a modified lattice gas model reflecting a discrete-continuous distribution of mixture components in space with allowance for direct correlations in a quasi-chemical approximation. The calculating of σ is associated with the rejection priority of mechanical characteristics over chemical potential, which is traditional in continuum mechanics. The chemical potential governs local equilibrium distributions of components in the transitional region of a boundary, resulting in the need to use microscopic Gibbs–Duhem equations in a deformed lattice structure of a substance to determine the average distance between molecules (as lattice structure parameters) and to consider effective one-particle motions of components in a dense phase that alter these parameters. Calculations of the surface tension of dense mixtures in models ignoring the existence of vacancies and structural deformation are discussed.
- Published
- 2019
62. Calculation of the Surface Tension of the Vapor–Liquid Interface According to the Gibbs Thermodynamic Definition
- Author
-
E. S. Zaitseva and Yu. K. Tovbin
- Subjects
Materials science ,Thermodynamics ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Curvature ,01 natural sciences ,0104 chemical sciences ,Surface tension ,Metastability ,Lattice (order) ,Thermal ,Reliability criterion ,Vapor liquid ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
A procedure to calculate the surface tension is developed based on a modified lattice gas model (MLGM) for the vapor–liquid system in a strict correspondence to the thermodynamic Gibbs definition for any curvature of the boundary. It is shown that MLGM enables a calculation of molecular distributions in a layered model of the transition region of the interface with regard to the softness of a lattice structure. The state of coexisting phases must satisfy the Yang–Lee theory of condensation, and additional conditions for chemical, thermal, and mechanical equilibria are imposed on the properties of the transition region of an equilibrium droplet with any curvature in each layer. The new calculation procedure for the surface tension is compared with the existing calculation procedures for equilibrium and metastable droplets. A difference in size dependences of the surface tension σ(R) for equilibrium and metastable droplets with a radius R in vicinity of the line σ/σbulk = 1, where σbulk is the bulk surface tension, allows us to formulate the accuracy and reliability criterion for different modeling methods: if the mentioned line exceeds the calculation accuracy σ(R), then it indicates that the method does not correspond to the Gibbs definition.
- Published
- 2019
63. The effect of Cu nanoparticles on the characteristics of vapor–liquid interface of argon at various saturated temperatures by molecular dynamic simulation
- Author
-
Zohreh Mansoori, Abbas Abbassi, Shabnam Ghahremanian, and Davood Toghraie
- Subjects
Vapour density ,Materials science ,Argon ,Nanoparticle ,chemistry.chemical_element ,Thermodynamics ,Condensed Matter Physics ,Copper ,Surface tension ,Molecular dynamics ,chemistry ,Vapor liquid ,Physical and Theoretical Chemistry ,Nanoscopic scale - Abstract
In this study, the effect of copper nanoparticles on the interface properties of liquid–vapor argon is investigated by molecular dynamics simulation. Stoddard Ford potential function has been utilized to estimate the interactions of argon–argon and argon–copper particles. Simulation is done in the nanoscale computational domain to phase change of vapor to liquid at different saturated temperatures. Density values and surface tension for different cutoff radii are obtained. It is demonstrated that in the $$r_{\text{c}} = 4\sigma$$ calculated values are acceptable. Simulation results show that nanoparticles change the interface properties of liquid–vapor argon. With addition of nanoparticles, liquid density decreases and vapor density increases. Nanoparticles displace density distribution and cause fluctuations in the density profile. Also, surface tension increases with increase in nanoparticle concentration.
- Published
- 2019
64. The Vapor-Liquid Phase Diagram of Pure Methane Using Temperature-Dependent Interaction Parameters: A Monte Carlo Simulation
- Author
-
Ibrahim Suleiman Dr
- Subjects
chemistry.chemical_compound ,Materials science ,chemistry ,Monte Carlo method ,Thermodynamics ,Vapor liquid ,Methane ,Phase diagram - Abstract
Adopting temperature-dependent interaction parameters in the Lennard-Jones potential, the vapor-liquid phase diagram of methane was produced using NVT Gibbs Ensemble Monte Carlo technique. Published second virial coefficient data were used to fit a simple two-parameter temperature-dependent model for the interaction parameters. The simulations were carried out in the temperature range 120-190 K. The critical density and temperature were evaluated using Ising-scaling model. Using the temperature-dependent interaction parameters in the simulation has reduced the root mean square deviation by 94.7% compared to the temperature-independent interaction parameters. The evaluated critical temperature was enhanced using temperature-dependent interaction parameters, whereas the simulations using temperature-independent interaction parameters predict a better critical density value
- Published
- 2019
65. Isothermal vapor–liquid equilibria at 383.15–413.15 K for the binary system methanol + dimethyl carbonate and the pressure dependency of the azeotropic point
- Author
-
Katsumi Tochigi, Shinya Iino, Hiroyuki Matsuda, Kenji Ochi, Jürgen Gmehling, Dana Constantinescu, Mitsuaki Negishi, and Kiyofumi Kurihara
- Subjects
Activity coefficient ,Work (thermodynamics) ,010405 organic chemistry ,Chemistry ,General Chemical Engineering ,General Physics and Astronomy ,Thermodynamics ,02 engineering and technology ,01 natural sciences ,Isothermal process ,0104 chemical sciences ,chemistry.chemical_compound ,020401 chemical engineering ,Vapor liquid ,Binary system ,Methanol ,0204 chemical engineering ,Physical and Theoretical Chemistry ,Dimethyl carbonate ,UNIFAC - Abstract
The objective of this work was to study the behavior of the azeotropic points of the methanol + DMC system under elevated pressures. We obtained isothermal vapor–liquid equilibria (VLE) data for this system at 383.15, 403.15, and 413.15 K by a static method. The azeotropic points were determined from the experimental VLE data. The temperature and pressure dependencies of the determined azeotropic points are discussed and compared with ones measured at reduced pressure. The experimental VLE data were represented by two activity coefficient models (non-random two-liquid and Wilson models). We also tested the modified UNIFAC (Dortmund) model for prediction of the VLE and azeotropic points. The azeotropic points of this system could be obtained over the pressure range from reduced pressures to elevated ones.
- Published
- 2019
66. Measurement and correlation of vapor-liquid distribution coefficients of flavonoids in high pressure carbon dioxide – ethanol – water systems
- Author
-
Richard L. Smith, Masaki Ota, Hiroshi Inomata, Yoshiyuki Sato, and Soma Sato
- Subjects
chemistry.chemical_classification ,Ethanol ,General Chemical Engineering ,Flavonoid ,Analytical chemistry ,General Physics and Astronomy ,chemistry.chemical_compound ,Hildebrand solubility parameter ,chemistry ,High pressure ,Carbon dioxide ,Vapor liquid ,Physical and Theoretical Chemistry ,Ternary operation ,Dimensionless quantity - Abstract
Vapor-liquid equilibria (VLE) and distribution coefficients (K-values) of carbon dioxide (CO2) - ethanol - water ternary systems and CO2 - ethanol - water - flavonoid (flavone, 6-methoxyflavone or 7-hydroxyflavone) quaternary systems were measured with a flow type apparatus at (313 to 353) K and (10 to 20) MPa. CO2 - ethanol - flavonoid ternary systems were measured at a nominal range of temperatures and pressures. The K-values of all flavonoids increased with increasing pressure. It was also indicated that the K-values of relatively lipophilic components such as flavone and 6-methoxyflavone increased with increasing water composition in feed while those of relatively hydrophilic components such as 7-hydroxyflavone increased with increasing ethanol composition in feed. A simple dimensionless relationship in terms of the K-values of the solvents (KCO2, KEtOH, KH2O) and the entropy-based solubility parameters of the vapor and liquid phases was developed to correlate the K-values of the three solutes in the CO2 - ethanol - water systems over the full range of conditions studied.
- Published
- 2019
67. Process intensification in vapor–liquid mass transfer: The state-of-the-art
- Author
-
Xingang Li, Xin Gao, Chuanhui Wu, Hong Li, and Zhiqiang Hao
- Subjects
Mass transfer coefficient ,Global energy ,Environmental Engineering ,business.industry ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Biochemistry ,law.invention ,020401 chemical engineering ,law ,Scientific method ,Mass transfer ,Environmental science ,Vapor liquid ,0204 chemical engineering ,0210 nano-technology ,Process engineering ,business ,Distillation - Abstract
The concept of process intensification (PI) has absorbed diverse definitions and stays true to the mission—“do more with less”, which is an approach purposed by chemical engineers to solve the global energy & environment problems. To date, the focus of PI has been on processes mainly involving vapor/liquid systems. Based on the fundamental principles of vapor–liquid mass transfer process like distillation and absorption, there are three strategies to intensify interphase mass transfer: enhancing the overall driving force, improving the mass transfer coefficient and enlarging the vapor–liquid interfacial area. More specifically, this article herein provides an overview of various technologies to strengthen the vapor–liquid mass transfer, including application of external fields, addition of third substances, micro-chemical technology and usage of solid foam, with the objective to contribute to the future developments and potential applications of PI in scientific research and industrial sectors.
- Published
- 2019
68. Isobaric Vapor–Liquid Equilibria of Binary Mixtures of Diethyl Carbonate with Methyl Acetate, n-Propyl Acetate, or Amyl Acetate at 100.17 kPa
- Author
-
Hongmei Du, Zhiping Du, Xia Yin, Zhiguo Yan, Chaochen Du, and Bingwen Long
- Subjects
General Chemical Engineering ,Methyl acetate ,N-propyl acetate ,Diethyl carbonate ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,020401 chemical engineering ,chemistry ,Carbonate ,Organic chemistry ,Isobaric process ,Vapor liquid ,0204 chemical engineering ,Amyl acetate - Abstract
Carbonate esters and esters are widely used in the pharmaceutical industry. It is important to enrich the vapor–liquid equilibrium (VLE) database of these components. In this article, the isobaric ...
- Published
- 2019
69. Study of Vapor–Liquid Equilibria for Acetic Acid + n-Propyl Acetate + Isopropyl Acetate Systems
- Author
-
Geng Li, Bo Jing, and Xianqing Yin
- Subjects
UNIQUAC ,Ternary numeral system ,organic chemicals ,General Chemical Engineering ,N-propyl acetate ,General Chemistry ,Isopropyl acetate ,Propene ,chemistry.chemical_compound ,Acetic acid ,chemistry ,Non-random two-liquid model ,Vapor liquid ,Nuclear chemistry - Abstract
A mixture of acetic acid, n-propyl acetate, and isopropyl acetate, which needs to be separated, is obtained when isopropyl acetate is produced from acetic acid and propene. The vapor–liquid equilibria (VLE) for the acetic acid + n-propyl acetate + isopropyl acetate ternary system and three subsystems were studied with ebulliometry at (20, 40, 60, 80, and 101.3) kPa. The vapor-phase nonideality was described by the Hayden–O’Connell (HOC) equation, and the liquid-phase nonideality was represented by the NRTL model and the UNIQUAC model, respectively. The model parameters for acetic acid–n-propyl acetate, acetic acid–isopropyl acetate, and n-propyl acetate–isopropyl acetate were acquired from the experimental data with the aid of Aspen Plus. The maximum overall average deviation of temperature between the experiment and model predictions is 0.46 K for the NRTL-HOC model and 0.47 K for the UNIQUAC-HOC model. The VLE data and the model parameters acquired may provide basic information for the separation of iso...
- Published
- 2019
70. Application of the modified molecular interaction volume model (M-MIVM) to vapor-liquid phase equilibrium of binary alloys in vacuum distillation
- Author
-
DongPing Tao and Heng Dai
- Subjects
010302 applied physics ,Activity coefficient ,Materials science ,Field (physics) ,Vacuum distillation ,Phase equilibrium ,Binary number ,Thermodynamics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Interaction volume ,01 natural sciences ,Surfaces, Coatings and Films ,0103 physical sciences ,Curve fitting ,Vapor liquid ,0210 nano-technology ,Instrumentation - Abstract
Thermodynamic models such as the Wilson model and molecular interaction volume model (MIVM) are known for their use in the calculation of activity coefficients of symmetric systems like Pb-Sn and Pb-Sb, but are deficient in handling asymmetric systems like Ag-Sn and Cu-Sn. Unfortunately, in metallurgical field, including vacuum metallurgy, the symmetric systems only account for a small part of liquid alloys, while the asymmetric systems take up a majority proportion. To overcome this application limitation of the Wilson model and MIVM in vacuum metallurgy, the modified molecular interaction volume model (M-MIVM) was applied. In contrast with Wilson model and MIVM, the M-MIVM exhibited remarkable superiority in data fitting of activity coefficient of binary asymmetric systems, which effectively increased the accuracy of predicting the activities of the multicomponent systems containing corresponding binary asymmetric systems. Therefore, M-MIVM made possible a more accurate vapor-liquid phase equilibrium diagram of asymmetric systems. In addition, since M-MIVM is a modification of the MIVM, it retains MIVM's capabilities to predict separation coefficient and calculate vapor-liquid equilibrium (VLE) of symmetric systems under quasi-vacuum condition. These identified advantages made M-MIVM, when compared with existing models, to have better accuracy and wider scope of application in vacuum metallurgy.
- Published
- 2019
71. High-Pressure Vapor−Liquid Equilibria of 1-Alkyl-1-Methylpyrrolidinium Bis(trifluoromethylsulfonyl)imide Ionic Liquids and CO2
- Author
-
Robert V. Fox, Aaron M. Scurto, Donna L. Baek, Ana Rita C. Morais, Mark B. Shiflett, Tugba Turnaoglu, and David L. Minnick
- Subjects
chemistry.chemical_classification ,Chemistry ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,020401 chemical engineering ,High pressure ,Carbon dioxide ,Ionic liquid ,Physical chemistry ,Vapor liquid ,0204 chemical engineering ,Imide ,Alkyl - Abstract
The high-pressure vapor–liquid equilibrium for the binary systems of carbon dioxide (CO2) and a series of 1-alkyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquids ([CnC1pyr][N...
- Published
- 2019
72. Reconsideration of the alpha coefficient in NRTL model on the vapor liquid phase equilibrium description of refrigerant mixtures
- Author
-
Jun Shen, Xueqiang Dong, Maoqiong Gong, and Yanxing Zhao
- Subjects
Physics ,Work (thermodynamics) ,Phase equilibrium ,Mechanical Engineering ,Thermodynamics ,02 engineering and technology ,Building and Construction ,Alpha (finance) ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Refrigerant ,Moment (mathematics) ,Dipole ,020401 chemical engineering ,Non-random two-liquid model ,Vapor liquid ,0204 chemical engineering - Abstract
The NRTL equation provides a good representation of vapor-liquid equilibrium of mixed-refrigerants, but it needs three parameters for each pair of components, including a non-randomness parameter alpha. In order to reduce the number of adjustable parameters from three to two, this work aims to establish an adequate expression for alpha in terms of readily available molecular parameters. The regressed alpha coefficients vary from -1 to 10, while 74% of them are between 0 and 1. Alpha has a great effect on the AARDp, although there is a region with a small AARDp difference. The relationship between alpha and molecular weight, dipole moment is established. As expected, positive correlation between alpha and molecular weight, while negative correlation between alpha and dipole is found. Better AARDp (0.59%) is achieved by a proposed equation, comparing to alpha = (0.2, 0.3, 0.4 and 0.47), although it is slightly worse than the regressed alpha.
- Published
- 2019
73. INFLUENCE OF THE STRUCTURE OF VAPOR-LIQUID DROPS ON HEAT EXCHANGE IN BOILING OF EMULSIONS OF IMMISCIBLE LIQUIDS
- Author
-
A. K. Rozentsvaig and Cheslav S. Strashinskii
- Subjects
Materials science ,Chemical engineering ,Boiling ,Heat exchanger ,Vapor liquid ,Atomic and Molecular Physics, and Optics - Published
- 2019
74. Modeling vapor-liquid phase equilibria of hydrogen sulfide and water system using a cubic EOS-GEX model
- Author
-
Haining Zhao, Jianqiao Liu, Zhengbao Fang, and Hongbin Jing
- Subjects
Aqueous solution ,010405 organic chemistry ,Chemistry ,General Chemical Engineering ,Hydrogen sulfide ,Salt effect ,Aqueous two-phase system ,General Physics and Astronomy ,Thermodynamics ,02 engineering and technology ,01 natural sciences ,Chemical reaction ,0104 chemical sciences ,chemistry.chemical_compound ,020401 chemical engineering ,Phase (matter) ,Vapor liquid ,0204 chemical engineering ,Physical and Theoretical Chemistry ,Hydrate - Abstract
Vapor-liquid phase equilibria of the H2S H2O mixture were correlated by use of a cubic EOS-GEX over temperature and pressure range of 0.1–30 MPa and 278–627K. Average absolute deviations (AAD%) between the modeling results and the experimental data taken from literature for both the H2S-rich and the aqueous phases were found less than 5%. The new sets of EOS-GEX model parameters for H2S H2O mixture were evaluated from the experimental data over the above-mentioned temperature and pressure range. The proposed model was compared with the three previous published models and we discussed the advantages and the disadvantages for each of them. This study demonstrated that the advantages of the cubic EOS-GEX model in calculating phase equilibria of H2S H2O mixture over currently available models, especially at high pressures. The hydrate equilibrium, the salt effect, and the chemical reactions in the aqueous phase were not considered during phase equilibrium calculation in this study.
- Published
- 2019
75. Synthesis and characterization of carbon-poor SiC nanowires via vapor-liquid-solid growth mechanism
- Author
-
Laifei Cheng, Xu Zeshui, Chuchu Guo, Fang Ye, and Zhaochen Li
- Subjects
010302 applied physics ,Materials science ,Morphology (linguistics) ,Process Chemistry and Technology ,Nanowire ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,C content ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Characterization (materials science) ,Reaction rate ,chemistry ,Chemical engineering ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,Vapor liquid ,0210 nano-technology ,Carbon ,Pyrolysis - Abstract
Nanowires growth via vapor-liquid-solid mechanism leads to high-quality SiC nanowires. C content is key issue affecting the morphology and composition of SiC nanowires. Here, we report the synthesis and growth mechanism of 3C-SiC nanowires containing reduced amount of C, which are grown on single-crystal Si via pyrolysis of polycarbosilane (PCS) by adjusting pyrolysis temperature and precursor. SiC nanowires have a diameter of 50 nm, while their thickness is 43.75 µm. High-temperature stability of precursors with multiple side-chain groups has an impact on the reaction rate, in result the solid precursor state and pyrolysis temperature at 1350 °C are beneficial to the formation of pure carbon-poor SiC nanowires.
- Published
- 2019
76. Vapor–Liquid Phase Equilibrium for Separation of Isopropanol from Its Aqueous Solution by Choline Chloride-Based Deep Eutectic Solvent Selected by COSMO-SAC Model
- Author
-
Jun Gao, Haihua Jiang, Lianzheng Zhang, Yixin Ma, Yinglong Wang, and Dongmei Xu
- Subjects
Aqueous solution ,Phase equilibrium ,Chemistry ,General Chemical Engineering ,Inorganic chemistry ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,law.invention ,Deep eutectic solvent ,body regions ,chemistry.chemical_compound ,020401 chemical engineering ,Magazine ,law ,parasitic diseases ,Vapor liquid ,0204 chemical engineering ,Distillation ,Eutectic system ,Choline chloride - Abstract
To separate isopropanol from its aqueous solution by distillation, the deep eutectic solvents (DESs) with choline chloride, which were screened using the COSMO-SAC mode, were applied to eliminate t...
- Published
- 2019
77. Vapor-liquid-equilibria of fuel-nitrogen systems at engine-like conditions measured with Raman spectroscopy in micro capillaries
- Author
-
Tobias C. Klima and Andreas Braeuer
- Subjects
inorganic chemicals ,Materials science ,Thermodynamic equilibrium ,Capillary action ,020209 energy ,General Chemical Engineering ,Flow (psychology) ,Analytical chemistry ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,Decane ,Physics::Fluid Dynamics ,Pressure range ,chemistry.chemical_compound ,symbols.namesake ,020401 chemical engineering ,0202 electrical engineering, electronic engineering, information engineering ,Physics::Chemical Physics ,0204 chemical engineering ,Organic Chemistry ,Nitrogen ,VLE, Vapor, Liquid, Raman spectroscopy, Solubility, Fuel, Capillary ,ddc:380 ,Condensed Matter::Soft Condensed Matter ,Fuel Technology ,chemistry ,symbols ,Vapor liquid ,Raman spectroscopy - Abstract
A fuel, here ethanol or decane, and nitrogen are fed at elevated pressure and temperature through a micro capillary of fused silica. The flow inside the capillary is characterized by alternating liquid- and vapor-phase segments that accommodate to thermodynamic equilibrium at the set temperature and pressure. The composition of the equilibrated liquid or vapor segments is measured in situ and remotely inside the micro capillary by Raman spectroscopy. Temperature-composition (Tx) vapor-liquid equilibria were measured for pressures between 3 MPa and 8 MPa and up to the highest mixture critical temperature of 593 K in this pressure range. Comparison to the scarce literature data for these conditions and to the GERG-2008 model, resembling the conditions in IC-engines at the time of injection, is shown.
- Published
- 2019
78. Vapor–Liquid Equilibria Study of the LiCl + CaCl2 + H2O System
- Author
-
Yu Zhou, Xiangyu Sun, Yan Wang, and Xianzhen Xu
- Subjects
chemistry.chemical_classification ,lcsh:Chemistry ,Materials science ,chemistry ,lcsh:QD1-999 ,Vapor pressure ,General Chemical Engineering ,Non-random two-liquid model ,Salt (chemistry) ,Thermodynamics ,Vapor liquid ,General Chemistry ,Solubility - Abstract
Vapor-liquid equilibrium (VLE) data are measured and reported for the LiCl + CaCl2 + H2O system. The experimental procedures were carried out with pressures between 6 and 101.3 kPa in a computer-controlled glass apparatus. We obtained the relationship between solubility of salt and vapor pressure by analyzing and summarizing the results. Then, a modified NRTL model based on the hypothesis of hydration was used in this paper. By correlation of literature and experimental data for LiCl + H2O, CaCl2 + H2O, and LiCl + CaCl2 + H2O (pressure spanning from 5 to 101.3 kPa), some parameters were modified for improving the accuracy of the calculation. Meanwhile, the model was successfully applied to predict the VLE data in LiCl + CaCl2 + H2O systems with the modified binary parameters.
- Published
- 2019
79. Sensitivity Analysis of Computations of the Vapor-Liquid Equilibria of Methane + Methanol or Glycols at Gas Hydrate Formation Conditions
- Author
-
Christopher E. Ozigagu and Anthony J. Duben
- Subjects
chemistry.chemical_compound ,chemistry ,Hydrogen bond ,Clathrate hydrate ,Thermodynamics ,Vapor–liquid equilibrium ,Monoethylene Glycol ,Vapor liquid ,Methanol ,Methane ,Triethylene glycol - Abstract
The Soave-Redlich-Kwong (SRK-EOS) and Peng-Robinson (PR-EOS) equations of state are used often to describe the behavior of pure substances and mixtures despite difficulties in handling substances, like water, with high polarity and hydrogen bonding. They were employed in studying the binary vapor-liquid equilibria (VLE) of methane + methanol, monoethylene glycol (MEG), and triethylene glycol (TEG). These liquids are used to inhibit the formation of gas hydrates. The investigation focused on the conditions at which methane-water clathrates can form 283.89 K to 323.56 K and 5.01 MPa to 18.48 MPa. The pressure of methane in methanol is overestimated by a factor of two by either the SRK-EOS or the PR-EOS. In the methane + MEG system, the predicted pressures for both equations of state are generally less than experimental pressure except for the highest concentration of methane in MEG calculated by the SRK-EOS. In the methane + TEG system, the predictions of both models are close and trend similarly. Because of the comparative lack of extensive experimental methane + TEG data, the similarity of the methane + TEG computed results can be used as a basis for further study of this system experimentally.
- Published
- 2019
80. Numerical simulation of water evaporation flow by infrared radiation at vapor-liquid interface
- Author
-
Masao Watanabe, Hirofumi Tabe, Kazumichi Kobayashi, Hiroyuki Fujii, Tsuyoshi Totani, and Kiryu Hiramatsu
- Subjects
Materials science ,Computer simulation ,Infrared ,Interface (computing) ,Flow (psychology) ,Vapor liquid ,Mechanics - Published
- 2019
81. Experiment and modeling of vapor–liquid equilibria for H2O+CH3OH+KCl and H2O+CH3OH+NaBr systems
- Author
-
Xi Wang, Zonghua Wang, Xianzhen Xu, and Yu Zhou
- Subjects
Activity coefficient ,Work (thermodynamics) ,Materials science ,UNIQUAC ,General Chemical Engineering ,Thermodynamics ,02 engineering and technology ,General Chemistry ,Electrolyte ,021001 nanoscience & nanotechnology ,Computer Science Applications ,Gibbs free energy ,Condensed Matter::Soft Condensed Matter ,Solvent ,symbols.namesake ,020401 chemical engineering ,symbols ,Vapor liquid ,Physics::Chemical Physics ,0204 chemical engineering ,0210 nano-technology - Abstract
In this work, vapor–liquid equilibrium (VLE) data were reported on mixed solvent electrolyte systems containing H2O+CH3OH+KCl and H2O+CH3OH+NaBr. The measurements were carried out in a computer-controlled glass apparatus. A new model based on UNIQUAC equation was proposed for the correlation of vapor–liquid equilibria in mixed solvent electrolyte systems. The model for the excess Gibbs energy was modified from the UNIQUAC equation, and the activity coefficients were calculated by UNIQUAC terms and solvent-solution effect terms. In addition, an assumption for the solution effect was introduced into this model. Experiment and literature data for mixed solvent electrolyte systems were successfully correlated using the proposed model.
- Published
- 2018
82. Dual stimuli-responsive polysulfone membranes with interconnected networks by a vapor-liquid induced phase separation strategy
- Author
-
Gang Wang, Li Jing Zhu, Zhixiang Zeng, Qun Ji Xue, and Hai Ming Song
- Subjects
Materials science ,02 engineering and technology ,Permeation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,Biomaterials ,Nanopore ,Viscosity ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Membrane ,chemistry ,Chemical engineering ,law ,Copolymer ,Vapor liquid ,Polysulfone ,0210 nano-technology ,Filtration - Abstract
Dual pH- and thermo-responsive polysulfone (PSf) membranes with three-dimensionally interconnected networks are fabricated by introducing poly(acrylic acid-co-N-isopropylacrylamide) (P(AA-NIPAm)) into the membrane surfaces and pore walls during membrane formation via a vapor-liquid induced phase separation (V-LIPS) process. After introducing the copolymers of P(AA-NIPAm), the fabricated membranes exhibit impressive open network pores on the surfaces, meanwhile their cross-sectional structure turns from classical asymmetric finger-like structure into bi-continuous nanopores throughout the whole thickness of membrane, due to high solution viscosity and low mass transfer rate of VIPS process. Furthermore, pure water permeation tests show that the pure water permeation (Lp) and the molecular weight cutoff (MWCO) of the fabricated PSf/P(AA-NIPAm) membranes increases sharply as the solution pH decreases from 12.5 to 1.5 and the feed temperature increases from 25 to 50 °C, attributing to the increasing pore size. With the decreasing mass ratio of AA to NIPAm, the pH-responsive coefficient decreases, while the temperature- responsive coefficient increases. In particular, for the fabricated membrane with the mass ratio of AA to NIPAm of 3 to 2, Lp changes from ∼16.0 to ∼821.4 L m−2 h−1 bar−1 and MWCO increases from ∼223.1 to ∼1493.2 kDa, as the filtration experiments are operated with feed pH and temperature of 12.5/25 °C and 1.5/50 °C respectively. The results proposed in this study provide a novel mode for design and development dual responsive porous membranes in situ, which will enable good separation of various materials and expand the scope of membrane applications.
- Published
- 2018
83. The role of vapor-liquid equilibria during the Fischer-Tropsch Synthesis
- Author
-
Alejo Aguirre, M. Fernanda Neria d'Angelo, Chemical Reactor Engineering, and EIRES Chem. for Sustainable Energy Systems
- Subjects
Materials science ,Applied Mathematics ,General Chemical Engineering ,Fischer–Tropsch process ,Product distribution ,02 engineering and technology ,General Chemistry ,Fischer-Tropsch synthesis ,021001 nanoscience & nanotechnology ,Industrial and Manufacturing Engineering ,Vapor-liquid equilibria ,020401 chemical engineering ,Reactor modelling ,Vapor liquid ,0204 chemical engineering ,0210 nano-technology ,Nuclear chemistry - Abstract
This work analyzes the effect of the vapor-liquid equilibria (VLE) on the productivity and the reactor performance during the Fischer-Tropsch Synthesis (FTS). A reactor model is developed considering the VLE and the local variation of the chain growth probability with temperature and the H2/CO ratio. The model describes the VLE with four different levels of complexity to assess the error introduced by making certain model simplifications. The results show that a simplified VLE model that only accounts for the VLE of CO and H2 offers an attractive alternative since it presents a good accuracy while saving computational time and efforts. Additionally, this work shows that the VLE significantly influences the liquid holdup and the pressure drop. Likewise, the catalyst efficiency is strongly affected by the liquid concentration, and therefore by the VLE. Thus, a full VLE description of reactants and products is needed for the accurate modeling of the FTS reactor.
- Published
- 2021
84. High-pressure vapor + liquid equilibria for the binary system CO2 + (E)-2-hexenal
- Author
-
Juan C. de la Fuente, Roberto I. Canales, Pablo López-Porfiri, and Rafael Villablanca-Ahues
- Subjects
Materials science ,General Chemical Engineering ,Mixing (process engineering) ,Thermodynamics ,Density ,02 engineering and technology ,(E)-2-hexenal ,01 natural sciences ,Isothermal process ,chemistry.chemical_compound ,Viscosity ,Experimental ,020401 chemical engineering ,Phase (matter) ,Binary system ,Vapor + liquid equilibria ,0204 chemical engineering ,Physical and Theoretical Chemistry ,010405 organic chemistry ,Modeling ,Condensed Matter Physics ,0104 chemical sciences ,chemistry ,Carbon dioxide ,High pressure ,Vapor liquid - Abstract
The isothermal vapor + liquid equilibria of carbon dioxide + (E)-2-hexenal (a key apple aroma) was measured using a visual equilibrium cell with an analytic methodology. The selected isotherms were (313.2, 323.2 and 333.2) K, and the pressures assessed ranged from (2.2–9.8) MPa. The thermodynamic consistency of the experimental data was verified, and the uncertainties of the molar fractions of the vapor and liquid phases were estimated. The density and dynamic viscosity of pure (E)-2-hexenal were measured at 101.13 kPa and temperatures from (292.2–353.2) K. Two equations of state were selected to model the vapor + liquid equilibria. The Peng-Robinson with two different mixing rules, and the Perturbed Chain - Statistical Associating Fluid Theory. The phase envelopes showed a critical pressure, detected at carbon dioxide molar fractions ≥ 95 % mol∙mol−1.
- Published
- 2021
85. Liquid-liquid, vapor-liquid and vapor-liquid-liquid experimental equilibrium of the system water + 1-butanol + 2-butanol at 101.3 kPa and data correlation
- Author
-
Universidad de Alicante. Departamento de Ingeniería Química, Universidad de Alicante. Instituto Universitario de Ingeniería de los Procesos Químicos, Garcia-Cano, Jorge, Saquete Ferrándiz, María Dolores, Universidad de Alicante. Departamento de Ingeniería Química, Universidad de Alicante. Instituto Universitario de Ingeniería de los Procesos Químicos, Garcia-Cano, Jorge, and Saquete Ferrándiz, María Dolores
- Abstract
In this work, the liquid-liquid equilibrium data of the system water + 1-butanol + 2-butanol was studied at 303.15 and 313.15 K. In addition, the vapor-liquid and vapor-liquid-liquid equilibrium at 101.3 kPa was also determined experimentally. The effect of the temperature on the binary water + 2-butanol system and on the ternary system was analysed. Several correlations were tested using the experimental data. The viability of using LLE correlations to calculate LLE on the one side and VLE on the other side and the viability of using the VLE correlation to calculate VLE and LLE were studied using UNIQUAC and NRTL models. A comparison of these result with the UNIFAC predictive model was performed.
- Published
- 2020
86. Correlations for the Estimation of Thermodynamic Properties of Pure Substances in the Liquid, Perfect Gas or Vapor–Liquid States
- Author
-
Jean-Noël Jaubert and Romain Privat
- Subjects
Materials science ,Thermodynamics ,Vapor liquid ,Perfect gas - Published
- 2021
87. Low-Pressure Vapor–Liquid and Liquid–Liquid Equilibria of Binary Systems: Activity-Coefficient Models
- Author
-
Jean-Noël Jaubert and Romain Privat
- Subjects
Activity coefficient ,Materials science ,Liquid liquid ,Thermodynamics ,Binary number ,Vapor liquid - Published
- 2021
88. Liquid–liquid and vapor–liquid–liquid equilibrium
- Author
-
İsmaı̇l Tosun
- Subjects
Materials science ,Chemical engineering ,Liquid liquid ,Vapor liquid - Published
- 2021
89. Vapor-liquid and liquid-liquid equilibria in the water + poly(propylene glycol) system
- Author
-
Jan Pavlíček, Ivan Wichterle, Grozdana Bogdanić, Pavel Izák, and Jan Rotrekl
- Subjects
Materials science ,Thermodynamics ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Polyvinyl alcohol ,Lower critical solution temperature ,chemistry.chemical_compound ,Phase (matter) ,Materials Chemistry ,Liquid liquid ,Vapor–liquid equilibrium ,Liquid–liquid equilibrium ,Polymer–solvent system ,Correlation ,Physical and Theoretical Chemistry ,Spectroscopy ,chemistry.chemical_classification ,UNIQUAC ,Interaction model ,Polymer ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,chemistry ,Vapor liquid ,0210 nano-technology - Abstract
The aim of this study was to investigate phase equilibria in a water + poly(propylene glycol) [Mn = 425 g mol−1] system. Vapor-liquid equilibria (VLE) were determined ebulliometrically in the completely miscible region with higher water concentrations at isotherms 323.15, 333.15, 343.15, and 353.15 K. These data were correlated with the UNIQUAC free-volume (FV) model to be consistent with our previous studies. Liquid-liquid equilibrium (LLE) was determined using the cloud-point method at 320–350 K, and lower critical solution temperature was found at 320.2 K. LLE was correlated with the entropic FV-UNIQUAC segmental interaction model developed earlier, which is suited for correlation and calculation of LLE of polymer solutions. We estimated new binary segmental interaction parameters for interactions between propylene glycol and water segments.
- Published
- 2021
90. Thermodynamics of the Vapor–Liquid–Solid Growth of Ternary III–V Nanowires in the Presence of Silicon
- Author
-
Vladimir G. Dubrovskii, Hadi Hijazi, and Mohammed Zeghouane
- Subjects
Materials science ,Silicon ,General Chemical Engineering ,Nucleation ,Nanowire ,chemistry.chemical_element ,02 engineering and technology ,doping ,01 natural sciences ,Article ,Catalysis ,lcsh:Chemistry ,vapor–liquid–solid ,0103 physical sciences ,Physics::Atomic and Molecular Clusters ,General Materials Science ,Chemical composition ,010302 applied physics ,Doping ,ternary alloys ,silicon ,021001 nanoscience & nanotechnology ,Chemical engineering ,chemistry ,nanowires ,lcsh:QD1-999 ,Vapor liquid ,0210 nano-technology ,Ternary operation - Abstract
Based on a thermodynamic model, we quantify the impact of adding silicon atoms to a catalyst droplet on the nucleation and growth of ternary III&ndash, V nanowires grown via the self-catalyzed vapor&ndash, liquid&ndash, solid process. Three technologically relevant ternaries are studied: InGaAs, AlGaAs and InGaN. For As-based alloys, it is shown that adding silicon atoms to the droplet increases the nanowire nucleation probability, which can increase by several orders magnitude depending on the initial chemical composition of the catalyst. Conversely, silicon atoms are found to suppress the nucleation rate of InGaN nanowires of different compositions. These results can be useful for understanding and controlling the vapor&ndash, solid growth of ternary III&ndash, V nanowires on silicon substrates as well as their intentional doping with Si.
- Published
- 2021
91. Understanding the Surface Potential of Water
- Author
-
Schenter, Gregory
- Published
- 2011
- Full Text
- View/download PDF
92. One-dimensional twisted and tubular structures of zinc oxide by semiconductor-catalyzed vapor-liquid-solid synthesis
- Author
-
Dmitri N. Zakharov, Sampath Kommandur, Michael A. Filler, Frances M. Ross, Hae Yeon Lee, and Thang Pham
- Subjects
Nanostructure ,Materials science ,Nanowire ,Oxide ,chemistry.chemical_element ,FOS: Physical sciences ,Bioengineering ,02 engineering and technology ,Zinc ,010402 general chemistry ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,Condensed Matter::Materials Science ,General Materials Science ,Electrical and Electronic Engineering ,Softening ,Condensed Matter - Materials Science ,business.industry ,Mechanical Engineering ,Materials Science (cond-mat.mtrl-sci) ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,3. Good health ,Semiconductor ,chemistry ,Chemical engineering ,Mechanics of Materials ,Vapor liquid ,0210 nano-technology ,business - Abstract
The exploration of new catalysts for the vapor-liquid-solid (VLS) synthesis of one-dimensional (1-D) materials promises to yield new morphologies and functionality. Here, we show, for the model ZnO system, that this possible using a semiconductor (Ge) catalyst. In particular, two unusual morphologies are described: twisted nanowires and twisted nanotubes, in addition to the usual straight nanowires. The twisted nanotubes show large hollow cores and surprisingly high twisting rates (up to 9o/{\mu}m), which cannot be easily explained through the Eshelby twist model. A combination of ex situ and in situ transmission electron microscopy measurements suggest that the hollow core results from a competition between growth and etching at the Ge-ZnO interface during synthesis. The twisting rate is consistent with a softening of elastic rigidity. These results indicate that the use of unconventional, nonmetallic catalysts provide opportunities to synthesize unusual oxide structures with potentially useful properties., Comment: 27 pages, 5 figures
- Published
- 2020
93. Minimal phase-field crystal modeling of vapor-liquid-solid coexistence and transitions
- Author
-
Zhirong Liu, Zhi-Feng Huang, Wenhui Duan, and Zi-Le Wang
- Subjects
Condensed Matter - Materials Science ,Materials science ,Physics and Astronomy (miscellaneous) ,Phase field crystal ,Vapor pressure ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,Thermal expansion ,Lattice constant ,Chemical physics ,Crystal model ,General Materials Science ,Vapor liquid ,Material properties ,Phase diagram - Abstract
A phase-field crystal model based on the density-field approach incorporating high-order interparticle direct correlations is developed to study vapor-liquid-solid coexistence and transitions within a single continuum description. Conditions for the realization of the phase coexistence and transition sequence are systematically analyzed and shown to be satisfied by a broad range of model parameters, demonstrating the high flexibility and applicability of the model. Both temperature-density and temperature-pressure phase diagrams are identified, while structural evolution and coexistence among the three phases are examined through dynamical simulations. The model is also able to produce some temperature and pressure related material properties, including effects of thermal expansion and pressure on equilibrium lattice spacing, and temperature dependence of saturation vapor pressure. This model can be used as an effective approach for investigating a variety of material growth and deposition processes based on vapor-solid, liquid-solid, and vapor-liquid-solid growth.
- Published
- 2020
94. Vapor-Liquid-Solid Growth and Optoelectronics of Gallium Sulfide van der Waals Nanowires
- Author
-
Eli Sutter, Peter Sutter, Jacob S. French, Stephan Sutter, and Juan Carlos Idrobo
- Subjects
Nanostructure ,Materials science ,business.industry ,General Engineering ,Nanowire ,General Physics and Astronomy ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Gallium sulfide ,0104 chemical sciences ,symbols.namesake ,Semiconductor ,symbols ,General Materials Science ,Vapor liquid ,van der Waals force ,Photonics ,0210 nano-technology ,business - Abstract
Nanowires of layered van der Waals (vdW) crystals are of interest due to structural characteristics and emerging properties that have no equivalent in conventional 3D crystalline nanostructures. Here, vapor-liquid-solid growth, optoelectronics, and photonics of GaS vdW nanowires are studied. Electron microscopy and diffraction demonstrate the formation of high-quality layered nanostructures with different vdW layer orientation. GaS nanowires with vdW stacking perpendicular to the wire axis have ribbon-like morphologies with lengths up to 100 μm and uniform width. Wires with axial layer stacking show tapered morphologies and a corrugated surface due to twinning between successive few-layer GaS sheets. Layered GaS nanowires are excellent wide-bandgap optoelectronic materials with
- Published
- 2020
95. Diameter-controlled Growth of GeTe Phase-change Nanowires via a Au Catalyst-assisted Vapor–liquid–solid Mechanism
- Author
-
Min Zhang, Jinniu Zhang, Yonghong Tian, Jianzhi Gao, Hongbing Lu, Gang Li, Yafeng Zhang, and Kaixin Chen
- Subjects
Phase change ,Supersaturation ,Materials science ,Chemical engineering ,Growth parameter ,Nanowire ,Nanoparticle ,Vapor liquid ,Chemical vapor deposition ,Catalysis - Abstract
Growth of diameter-controlled GeTe phase-change nanowires (NWs) on Si substrates is demonstrated by a Au catalyst-assisted chemical vapor deposition (CVD) technique. Besides Au catalyst size, GeTe source powder amount, an uncommon growth parameter, is also employed to control the diameter of GeTe NWs. The diameter of GeTe NWs shows an obvious increase with the increase of both Au catalyst size and GeTe powder amount. By effectively controlling the Au nanoparticle size and GeTe powder amount, the diameters of GeTe NWs can be tunable in a wide range of 150 to 280 nm. The effects of the Au nanoparticle size and GeTe powder amount on the diameter of GeTe NWs are revealed in terms of supersaturation detailedly based on the Gibbs–Thomson effect.
- Published
- 2020
96. Field-effect transistor figures of merit for vapor–liquid–solid-grown Ge1-xSnx (x = 0.03–0.09) nanowire devices
- Author
-
Ray Duffy, Subhajit Biswas, Emmanuele Galluccio, Jessica Doherty, and Justin D. Holmes
- Subjects
Electron mobility ,Ge1-xSnx ,Low-temperature processing ,Materials science ,Nanowire ,02 engineering and technology ,7. Clean energy ,01 natural sciences ,0103 physical sciences ,Materials Chemistry ,Electrochemistry ,Figure of merit ,Sub-threshold slope ,Electronics ,010302 applied physics ,business.industry ,Nanowires ,Contact resistance ,Material system ,021001 nanoscience & nanotechnology ,Electronic, Optical and Magnetic Materials ,MOSFETs ,Optoelectronics ,Field-effect transistor ,Vapor liquid ,Carrier mobility ,0210 nano-technology ,business - Abstract
Ge1-xSnx alloys form a heterogeneous material system with high potential for applications in both optoelectronic and high-speed electronics devices. The attractiveness of Ge1-xSnx lies in the ability to tune the semiconductor band gap and electronic properties as a function of Sn concentration. Advances in Ge1-xSnx material synthesis have raised expectations recently, but there are considerable problems in terms of device demonstration. Although Ge1-xSnx thin films have been previously explored experimentally, in-depth studies of the electrical properties of Ge1-xSnx nanostructures are very limited, specifically those on nanowires grown via a bottom-up vapor–liquid–solid (VLS) process using metal catalysts. In this study, a detailed electrical investigation is presented of nominally undoped Ge1-xSnx bottom-up-grown nanowire devices with different Sn percentages (3–9 at. %). The entire device fabrication process is performed at relatively low temperatures, the maximum temperature being 440 °C. Device current modulation is performed through backgating from a substrate electrode, achieving impressive on–off current (ION/IOFF) ratios of up to 104, showing their potential for electronic and sensor-based applications. Contact resistance (RC) extraction is essential for proper VLS-grown nanowire device electrical evaluation. Once the RC contribution is extracted and removed, parameter values such as mobility can change significantly, by up to 70% in this work. When benchmarked against other Ge1-xSnx electronic devices, the VLS-grown nanowire devices have potential in applications where a high ION/IOFF ratio is important and where thermal budget and processing temperatures are required to be kept to minimum.
- Published
- 2020
97. Temperature‐dependent vapor–liquid equilibria and solvation free energy estimation from minimal data
- Author
-
Ryan J. Gillis, William H. Green, Yunsie Chung, and Massachusetts Institute of Technology. Department of Chemical Engineering
- Subjects
Energy estimation ,Quantitative Biology::Biomolecules ,Materials science ,Environmental Engineering ,Phase equilibrium ,General Chemical Engineering ,Solvation ,Thermodynamics ,Vapor liquid ,Solubility ,Physics::Chemical Physics ,Biotechnology - Abstract
We present a new strategy to estimate the temperature‐dependent vapor–liquid equilibria and solvation free energies of dilute neutral molecules based on only their estimated solvation energy and enthalpy at 298 K. These two pieces of information coupled with matching conditions between the functional forms developed by Japas and Levelt Sengers for near critical conditions and by Harvey for low and moderate temperature conditions allow the fitting of a piecewise function that predicts the temperature‐dependent solvation energy for dilute solutes up to the critical temperature of the solvent. If the Abraham and Mintz parameters for the solvent and solute are available or can be estimated from group contributions, this method requires no experimental data and can still provide accurate estimates with an error of about 1.6 kJ/mol. This strategy, which requires minimal computational resources, is shown to compare well with other methods of temperature‐dependent solvation free energy prediction., Eni S.p.A. (Award 5210000949)
- Published
- 2020
98. Calculation of thermodynamic properties of vapor–liquid equilibria using ab initio intermolecular potential energy surfaces for dimer O2–O2
- Author
-
Nguyen Thi Ai Nhung and Pham Van Tat
- Subjects
Materials science ,010304 chemical physics ,Dimer ,Biophysics ,Ab initio ,chemistry.chemical_element ,Thermodynamics ,010402 general chemistry ,Condensed Matter Physics ,01 natural sciences ,Oxygen ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Ab initio quantum chemistry methods ,0103 physical sciences ,Intermolecular potential ,Vapor liquid ,Physical and Theoretical Chemistry ,Molecular Biology ,Energy (signal processing) - Abstract
The two 5-site potentials from ab initio calculations at the theoretical level CCSD(T) with correlation consistent basis sets aug-cc-pVmZ (with m = 4, 34) have been constructed from oxygen. The extrapolation ab initio energies were approximated by the basis sets aug-cc-pVmZ (m = 3, 4). These two potentials were constructed by using the ab initio intermolecular energy values and a non-linear least-squares fitting method. The second virial coefficients of oxygen were determined to demonstrate the accuracy of these ab initio 5-site potentials. These ab initio potentials were employed to estimate the thermodynamic properties of the vapor���liquid equilibria by GEMC simulation. The influence of ab initio potential alone and plus 3-body interaction Axilrod-Teller potential was investigated within GEMC simulation from 80 K to 140 K. The discrepancy between them is insignificant. This showed that the two 2-body 5-site potential functions can also be used together with the 3-body interaction Axilrod-Teller potential to generate the accurate thermodynamic properties of the liquid���vapor equilibria.
- Published
- 2020
99. Vapor-liquid equilibria and diffusion coefficients of difluoromethane, 1,1,1,2-tetrafluoroethane, and 2,3,3,3-tetrafluoropropene in low-viscosity ionic liquids
- Author
-
Ane Urtiaga, Salvador Asensio-Delgado, Fernando Pardo, Gabriel Zarca, and Universidad de Cantabria
- Subjects
Chemistry ,General Chemical Engineering ,Diffusion ,Thermodynamics ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,01 natural sciences ,1,1,1,2-Tetrafluoroethane ,0104 chemical sciences ,Refrigerant ,chemistry.chemical_compound ,020401 chemical engineering ,Solubility ,2,3,3,3-Tetrafluoropropene ,Ionic liquid ,Transport properties ,Organic compounds ,Solvents ,Vapor liquid ,0204 chemical engineering ,Difluoromethane - Abstract
The phase-down of hydrofluorocarbons (HFCs) established by the Kigali Amendment to the Montreal Protocol is leading to the formulation and commercialization of new refrigerant blends containing hydrofluoroolefins (HFOs), such as 2,3,3,3-tetrafluoropropene (R1234yf), and HFCs with moderate global warming potential, namely, difluoromethane (R32) and 1,1,1,2-tetrafluoroethane (R134a). Moreover, the recycling of refrigerants is attracting attention as a means to reduce the amount of new HFCs produced and their release to the environment. To that end, the use of ionic liquids has been proposed as entrainers to separate refrigerants with close-boiling points or azeotropic blends. Thus, the vapor?liquid equilibria and diffusion coefficients of the refrigerant?ionic liquid pairs formed by R32 + [C2mim][BF4], R134a + [C2mim][BF4], R134a+ [C2mim][OTf], R1234yf + [C2mim][OTf], and R1234yf + [C2mim][Tf2N] are studied using an isochoric saturation method at temperatures ranging from 283.15 to 323.15 K and pressures up to 0.9 MPa. In addition, the solubility behavior is successfully modeled using the nonrandom two-liquid activity-coefficient method, and the Henry?s law constants at infinite dilution, solvation energies, and infinite dilution activity coefficients are calculated. This research is supported by Project KET4F-Gas – SOE2/P1/P0823, which is co-financed by the European Regional Development Fund within the framework of Interreg Sudoe Programme. S. A-D. and F.P acknowledge the FPU grant (18/03939) and the post-doctoral fellowship (FJCI-2017-32884 Juan de la Cierva Formación), respectively, awarded by the Spanish Ministry of Science, Innovation and Universities.
- Published
- 2020
100. Controlled generation of vapor/liquid slug flows by local boiling in microgravity
- Author
-
Pau Bitlloch, Xavier Ruiz, Laureano Ramírez-Piscina, Jaume Casademunt, Universitat Politècnica de Catalunya. Departament de Física, and Universitat Politècnica de Catalunya. BIOCOM-SC - Grup de Biologia Computacional i Sistemes Complexos
- Subjects
inorganic chemicals ,Materials science ,Vapor pressure ,Capillary action ,Hydrostatic pressure ,Aerospace Engineering ,02 engineering and technology ,complex mixtures ,01 natural sciences ,010305 fluids & plasmas ,Physics::Fluid Dynamics ,0203 mechanical engineering ,Boiling ,Mass transfer ,0103 physical sciences ,Heat exchanger ,Mass flow rate ,Physics::Atomic Physics ,Physics::Atmospheric and Oceanic Physics ,020301 aerospace & aeronautics ,Física [Àrees temàtiques de la UPC] ,technology, industry, and agriculture ,food and beverages ,Mechanics ,equipment and supplies ,Ambients de microgravetat ,Vapor liquid ,Reduced gravity environments ,Microgravity - Abstract
We design, construct, and test a device for controlled boiling by means of local vapor bubble formation in a cavity that injects vapor bubbles in a capillary crossflow. The outcome of the device is a regular slug flow of approximately monodisperse bubbles that can be used for a variety of applications. The setup is designed to be independent of gravity level and is tested succesfully both in normal gravity and in microgravity using drop tower experiments. The device is calibrated by a systematic study determining the size and frequency of bubble formation as a function of pressure and flow conditions. Results turn out to be virtually independent of gravity. Different regimes of operations are identified and described, and basic properties of the behavior of the bubbles inside the nucleation cavity are discussed. The slug flow downstream the crossflow is characterized and shows some differences depending on gravity. Finally, we illustrate the use of a controlled regular slug flow generated by our device by using it as an input of a serpentine heat exchanger. This emphasizes an important virtue of our method for practical applications, namely, the ability to separate the process of bubble formation from the actual heat exchange by phase transformation in the region of interest.
- Published
- 2020
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.