1
|
Baca KR, Al-Barghouti K, Wang N, Bennett MG, Matamoros Valenciano L, May TL, Xu IV, Cordry M, Haggard DM, Haas AG, Heimann A, Harders AN, Uhl HG, Melfi DT, Yancey AD, Kore R, Maginn EJ, Scurto AM, Shiflett MB. Ionic Liquids for the Separation of Fluorocarbon Refrigerant Mixtures. Chem Rev 2024; 124:5167-5226. [PMID: 38683680 DOI: 10.1021/acs.chemrev.3c00276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
This review discusses the research being performed on ionic liquids for the separation of fluorocarbon refrigerant mixtures. Fluorocarbon refrigerants, invented in 1928 by Thomas Midgley Jr., are a unique class of working fluids that are used in a variety of applications including refrigeration. Fluorocarbon refrigerants can be categorized into four generations: chlorofluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, and hydrofluoroolefins. Each generation of refrigerants solved a key problem from the previous generation; however, each new generation has relied on more complex mixtures that are often zeotropic, near azeotropic, or azeotropic. The complexity of the refrigerants used and the fact that many refrigerants form azeotropes when mixed makes handling the refrigerants at end of life extremely difficult. Today, less than 3% of refrigerants that enter the market are recycled. This is due to a lack of technology in the refrigerant reclaim market that would allow for these complex, azeotropic refrigerant mixtures to be separated into their components in order to be effectively reused, recycled, and if needed repurposed. As the market for recovering and reclaiming refrigerants continues to grow, there is a strong need for separation technology. Ionic liquids show promise for separating azeotropic refrigerant mixtures as an entrainer in extractive distillation process. Ionic liquids have been investigated with refrigerants for this application since the early 2000s. This review will provide a comprehensive summary of the physical property measurements, equations of state modeling, molecular simulations, separation techniques, and unique materials unitizing ionic liquids for the development of an ionic-liquid-based separation process for azeotropic refrigerant mixtures.
Collapse
Affiliation(s)
- Kalin R Baca
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Karim Al-Barghouti
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Ning Wang
- Department of Chemical & Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Madelyn G Bennett
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Lucia Matamoros Valenciano
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Tessie L May
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Irene V Xu
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Max Cordry
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Dorothy M Haggard
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Abigail G Haas
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Ashley Heimann
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Abby N Harders
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Hannah G Uhl
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Diego T Melfi
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Andrew D Yancey
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Rajkumar Kore
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Edward J Maginn
- Department of Chemical & Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Aaron M Scurto
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Mark B Shiflett
- Wonderful Institute for Sustainable Engineering, 1536 West 15th Street, Lawrence, Kansas 66045, United States
- Department of Chemical and Petroleum Engineering, University of Kansas, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| |
Collapse
|
2
|
Nietiadi ML, Rosandi Y, Bringa EM, Urbassek HM. Collisions between CO, CO[Formula: see text], H[Formula: see text]O and Ar ice nanoparticles compared by molecular dynamics simulation. Sci Rep 2022; 12:13858. [PMID: 35974128 PMCID: PMC9381553 DOI: 10.1038/s41598-022-18039-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 08/04/2022] [Indexed: 12/01/2022] Open
Abstract
Molecular dynamics simulations are used to study collisions between amorphous ice nanoparticles consisting of CO, CO[Formula: see text], Ar and H[Formula: see text]O. The collisions are always sticking for the nanoparticle size (radius of 20 nm) considered. At higher collision velocities, the merged clusters show strong plastic deformation and material mixing in the collision zone. Collision-induced heating influences the collision outcome. Partial melting of the merged cluster in the collision zone contributes to energy dissipation and deformation. Considerable differences exist-even at comparable collision conditions-between the ices studied here. The number of ejecta emitted during the collision follows the trend in triple-point temperatures and increases exponentially with the NP temperature.
Collapse
Affiliation(s)
- Maureen L. Nietiadi
- Physics Department and Research Center OPTIMAS, University Kaiserslautern, Erwin-Schrödinger-Straße, 67663 Kaiserslautern, Germany
| | - Yudi Rosandi
- Department of Geophysics, Universitas Padjadjaran, Jatinangor, Sumedang 45363 Indonesia
| | - Eduardo M. Bringa
- CONICET and Facultad de Ingenería, Universidad de Mendoza, 5500 Mendoza, Argentina
- Centro de Nanotecnología Aplicada, Facultad de Ciencias, Universidad Mayor, 8580745 Santiago, Chile
| | - Herbert M. Urbassek
- Physics Department and Research Center OPTIMAS, University Kaiserslautern, Erwin-Schrödinger-Straße, 67663 Kaiserslautern, Germany
| |
Collapse
|
3
|
Molecular models for O2 and N2 from the second virial coefficient. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
4
|
Madin OC, Boothroyd S, Messerly RA, Fass J, Chodera JD, Shirts MR. Bayesian-Inference-Driven Model Parametrization and Model Selection for 2CLJQ Fluid Models. J Chem Inf Model 2022; 62:874-889. [PMID: 35129974 PMCID: PMC9217127 DOI: 10.1021/acs.jcim.1c00829] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A high level of physical detail in a molecular model improves its ability to perform high accuracy simulations but can also significantly affect its complexity and computational cost. In some situations, it is worthwhile to add complexity to a model to capture properties of interest; in others, additional complexity is unnecessary and can make simulations computationally infeasible. In this work, we demonstrate the use of Bayesian inference for molecular model selection, using Monte Carlo sampling techniques accelerated with surrogate modeling to evaluate the Bayes factor evidence for different levels of complexity in the two-centered Lennard-Jones + quadrupole (2CLJQ) fluid model. Examining three nested levels of model complexity, we demonstrate that the use of variable quadrupole and bond length parameters in this model framework is justified only for some chemistries. Through this process, we also get detailed information about the distributions and correlation of parameter values, enabling improved parametrization and parameter analysis. We also show how the choice of parameter priors, which encode previous model knowledge, can have substantial effects on the selection of models, penalizing careless introduction of additional complexity. We detail the computational techniques used in this analysis, providing a roadmap for future applications of molecular model selection via Bayesian inference and surrogate modeling.
Collapse
Affiliation(s)
- Owen C. Madin
- Department of Chemical & Biological Engineering, University of Colorado Boulder, Boulder, CO 80309
| | - Simon Boothroyd
- Boothroyd Scientific Consulting Ltd., 71-75 Shelton Street, London, Greater London, United Kingdom, WC2H 9JQ
| | | | - Josh Fass
- Computational & Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - John D. Chodera
- Department of Chemical & Biological Engineering, University of Colorado Boulder, Boulder, CO 80309
| | - Michael R. Shirts
- Department of Chemical & Biological Engineering, University of Colorado Boulder, Boulder, CO 80309
| |
Collapse
|
5
|
Befort BJ, DeFever RS, Tow GM, Dowling AW, Maginn EJ. Machine Learning Directed Optimization of Classical Molecular Modeling Force Fields. J Chem Inf Model 2021; 61:4400-4414. [PMID: 34402301 DOI: 10.1021/acs.jcim.1c00448] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Accurate force fields are necessary for predictive molecular simulations. However, developing force fields that accurately reproduce experimental properties is challenging. Here, we present a machine learning directed, multiobjective optimization workflow for force field parametrization that evaluates millions of prospective force field parameter sets while requiring only a small fraction of them to be tested with molecular simulations. We demonstrate the generality of the approach and identify multiple low-error parameter sets for two distinct test cases: simulations of hydrofluorocarbon (HFC) vapor-liquid equilibrium (VLE) and an ammonium perchlorate (AP) crystal phase. We discuss the challenges and implications of our force field optimization workflow.
Collapse
Affiliation(s)
- Bridgette J Befort
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Ryan S DeFever
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Garrett M Tow
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Alexander W Dowling
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Edward J Maginn
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| |
Collapse
|
6
|
|
7
|
Zhang N, Hu P, Chen L, Zhi L. Molecular modeling of vapor-liquid equilibrium properties of HFC-161 and its mixture HFC-161+HFO-1234yf. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.112896] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
8
|
Cai S, Tian S, Lu Y, Wang G, Pu Y, Peng K. Molecular Simulations of Adsorption and Energy Storage of R1234yf, R1234ze(z), R134a, R32, and their Mixtures in M-MOF-74 (M = Mg, Ni) Nanoparticles. Sci Rep 2020; 10:7265. [PMID: 32350321 PMCID: PMC7190729 DOI: 10.1038/s41598-020-64187-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 04/10/2020] [Indexed: 11/15/2022] Open
Abstract
The refrigerant circulation heat can be enhanced through the mutual transformation between thermal energy and surface energy during the adsorption and separation process of fluid molecules in porous materials. In this paper, the adsorption and energy storage of R1234ze(z), R1234yf, R32 and R134a, as well as their mixed refrigerants in Mg-MOF-74 and Ni-MOF-74 nanoparticles were investigated by means of molecular dynamics simulations and grand canonical Monte Carlo simulations. The results suggested that, in the case of pure refrigerant adsorption, the adsorption quantities of R32 and R134a in MOFs were higher than those of R1234yf and R1234ze(z). However, in the case of saturation adsorption, the desorption heat of R32 was lower than that of R1234yf and R1234ze(z). The addition of MOF-74 nanoparticles (NPs) could enhance the energy storage capacity of the pure refrigerant; besides, R1234yf and R1234ze(z) nanofluids had superior enhancement effect to that of R32 nanofluid. In mixed refrigerant adsorption, the adsorption quantities of R1234ze(z) and R1234yf were lower than those of R32 and R134a; with the increase in temperature, the adsorption of R1234ze(z) and R1234yf showed a gradually increasing trend, while that of R32 was gradually decreased.
Collapse
Affiliation(s)
- Shouyin Cai
- Key Laboratory of Low-grade Energy Utilization Technologies & Systems, Ministry of Education, College of Energy and Power Engineering, Chongqing University, Chongqing, 400044, P.R. China.,State Key Laboratory of Coal Mine Disaster Dynamics and Control, School of Resources and Safety Engineering, Chongqing University, Chongqing, 400044, P.R. China
| | - Sen Tian
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, School of Resources and Safety Engineering, Chongqing University, Chongqing, 400044, P.R. China.
| | - Yiyu Lu
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, School of Resources and Safety Engineering, Chongqing University, Chongqing, 400044, P.R. China
| | - Guangjin Wang
- Yunnan Key Laboratory of Sino-German Blue Mining and Utilization of Special Underground Space, Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming, 650093, P.R. China
| | - Yu Pu
- Key Laboratory of Low-grade Energy Utilization Technologies & Systems, Ministry of Education, College of Energy and Power Engineering, Chongqing University, Chongqing, 400044, P.R. China
| | - Kang Peng
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, School of Resources and Safety Engineering, Chongqing University, Chongqing, 400044, P.R. China.
| |
Collapse
|
9
|
Stephan S, Horsch MT, Vrabec J, Hasse H. MolMod – an open access database of force fields for molecular simulations of fluids. MOLECULAR SIMULATION 2019. [DOI: 10.1080/08927022.2019.1601191] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Simon Stephan
- Laboratory of Engineering Thermodynamics (LTD), TU Kaiserslautern, Kaiserslautern, Germany
| | - Martin T. Horsch
- STFC Daresbury Laboratory, Scientific Computing Department, Warrington, UK
| | - Jadran Vrabec
- Thermodynamics and Process Engineering, TU Berlin, Berlin, Germany
| | - Hans Hasse
- Laboratory of Engineering Thermodynamics (LTD), TU Kaiserslautern, Kaiserslautern, Germany
| |
Collapse
|
10
|
Liang HH, Li JY, Wang LH, Lin ST, Hsieh CM. Improvement to PR+COSMOSAC EOS for Predicting the Vapor Pressure of Nonelectrolyte Organic Solids and Liquids. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.8b06289] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hsin-Hao Liang
- Department of Chemical and Materials Engineering, National Central University, Taoyuan 32001, Taiwan
| | - Jian-Yi Li
- Department of Chemical and Materials Engineering, National Central University, Taoyuan 32001, Taiwan
| | - Li-Hsin Wang
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Shiang-Tai Lin
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Chieh-Ming Hsieh
- Department of Chemical and Materials Engineering, National Central University, Taoyuan 32001, Taiwan
| |
Collapse
|
11
|
A review of molecular simulation applied in vapor-liquid equilibria (VLE) estimation of thermodynamic cycles. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.05.101] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
12
|
Amini SK. Relative Populations of Some Tautomeric Forms of 2'-Deoxyguanosine-5-Fluorouridine Mismatch. J Phys Chem B 2018; 122:4433-4444. [PMID: 29608855 DOI: 10.1021/acs.jpcb.8b00818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The importance of the 2'-deoxyguanosine-uridine mispair as the most occurring mismatch in transcriptional studies of RNAs from DNAs is multiplied when 5-halo-substituted uridine species cause a serious increase in the probability of its occurrence. Many studies relate this higher probability to the existence of possible tautomeric and ionic forms of its constituent bases. According to these statements, relative populations of mismatches between 5-fluorouridine and both keto and enol forms of 2'-deoxyguanosine are computed by using a conformational search. In order to have a complete scan of all of the highly probable conformers in a moderate computational time, an extensive conformational search methodology is employed here, which benefits from the advantages of both the molecular dynamics simulations and quantum mechanics calculations. The population of an enolic tautomer of normal wobble orientation is about 0.057% of that of its keto tautomer, whereas the population of an enolic tautomer of reverse wobble orientation is about 0.0054% of that of its keto tautomer. Totally, the reverse wobble orientation is about six times more populated than the normal wobble orientation. Calculated populations are in good agreement with experimental populations of closely related compounds. The reliability of the applied methodology is certified, in part, by a good agreement obtained between some experimental data and corresponding Boltzmann-weighted average data of most probable conformers such as NMR parameters. The validation of this methodology is certified with high accuracy by applying it on the substituted diuridine pairs, where experimental populations are available. Not only are the calculated populations and NMR parameters of this test in very good agreement with the experimental data, but also they are free of the ambiguities mentioned by experimentalists.
Collapse
Affiliation(s)
- Saeed K Amini
- Chemistry and Chemical Engineering Research Center of Iran , Tehran , Iran
| |
Collapse
|
13
|
Wilson J, Faginas-Lago N, Vekeman J, Cuesta IG, Sánchez-Marín J, Sánchez de Merás A. Modeling the Interaction of Carbon Monoxide with Flexible Graphene: From Coupled Cluster Calculations to Molecular-Dynamics Simulations. Chemphyschem 2018; 19:774-783. [DOI: 10.1002/cphc.201701387] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Jake Wilson
- Instituto de Ciencia Molecular; Universitat de València; Catedràtic José Beltrán 2 46980 Paterna Spain
| | - Noelia Faginas-Lago
- Dipartimento di Chimica, Biologia e Biotecnologie; Università di Perugia, Consortium for Computational Molecular and Materials Sciences (CMS); Via Elce di Sotto 8 06123 Perugia Italy
| | - Jelle Vekeman
- Instituto de Ciencia Molecular; Universitat de València; Catedràtic José Beltrán 2 46980 Paterna Spain
| | - Inmaculada G. Cuesta
- Instituto de Ciencia Molecular; Universitat de València; Catedràtic José Beltrán 2 46980 Paterna Spain
- Departamento de Química Física; Universitat de València; Dr. Moliner 50 46100 Burjassot Spain
| | - José Sánchez-Marín
- Instituto de Ciencia Molecular; Universitat de València; Catedràtic José Beltrán 2 46980 Paterna Spain
| | - Alfredo Sánchez de Merás
- Instituto de Ciencia Molecular; Universitat de València; Catedràtic José Beltrán 2 46980 Paterna Spain
- Departamento de Química Física; Universitat de València; Dr. Moliner 50 46100 Burjassot Spain
| |
Collapse
|
14
|
Yao B, Mandrà S, Curry JO, Shaikhutdinov S, Freund HJ, Schrier J. Gas Separation through Bilayer Silica, the Thinnest Possible Silica Membrane. ACS APPLIED MATERIALS & INTERFACES 2017; 9:43061-43071. [PMID: 29156127 DOI: 10.1021/acsami.7b13302] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Membrane-based gas separation processes can address key challenges in energy and environment, but for many applications the permeance and selectivity of bulk membranes is insufficient for economical use. Theory and experiment indicate that permeance and selectivity can be increased by using two-dimensional materials with subnanometer pores as membranes. Motivated by experiments showing selective permeation of H2/CO mixtures through amorphous silica bilayers, here we perform a theoretical study of gas separation through silica bilayers. Using density functional theory calculations, we obtain geometries of crystalline free-standing silica bilayers (comprised of six-membered rings), as well as the seven-, eight-, and nine-membered rings that are observed in glassy silica bilayers, which arise due to Stone-Wales defects and vacancies. We then compute the potential energy barriers for gas passage through these various pore types for He, Ne, Ar, Kr, H2, N2, CO, and CO2 gases, and use the data to assess their capability for selective gas separation. Our calculations indicate that crystalline bilayer silica, which is less than a nanometer thick, can be a high-selectivity and high-permeance membrane material for 3He/4He, He/natural gas, and H2/CO separations.
Collapse
Affiliation(s)
- Bowen Yao
- Department of Chemistry, Haverford College , 370 Lancaster Avenue, Haverford, Pennsylvania 19041, United States
| | - Salvatore Mandrà
- Quantum Artificial Intelligence Laboratory (QuAIL), Mail Stop 269-1, NASA Ames Research Center , Moffett Field, California 94035, United States
- Stinger Ghaffarian Technologies Inc. , 7701 Greenbelt Road, Suite 400, Greenbelt, Maryland 20770, United States
| | - John O Curry
- Department of Chemistry, Haverford College , 370 Lancaster Avenue, Haverford, Pennsylvania 19041, United States
| | - Shamil Shaikhutdinov
- Department of Chemical Physics, Fritz Haber Institute , Faradayweg 4-6, Berlin 14195, Germany
| | - Hans-Joachim Freund
- Department of Chemical Physics, Fritz Haber Institute , Faradayweg 4-6, Berlin 14195, Germany
| | - Joshua Schrier
- Department of Chemistry, Haverford College , 370 Lancaster Avenue, Haverford, Pennsylvania 19041, United States
| |
Collapse
|
15
|
Affiliation(s)
- Michael Rouha
- Institute of Chemical Process Fundamentals, Czech Academy of Sciences, Prague, Czech Republic
| | - Ivo Nezbeda
- Institute of Chemical Process Fundamentals, Czech Academy of Sciences, Prague, Czech Republic
- Faculty of Science, J. E. Purkinje University, Ústí nad Labem, Czech Republic
| |
Collapse
|
16
|
Werth S, Stöbener K, Horsch M, Hasse H. Simultaneous description of bulk and interfacial properties of fluids by the Mie potential. Mol Phys 2016. [DOI: 10.1080/00268976.2016.1206218] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Stephan Werth
- Department of Mechanical and Process Engineering, Laboratory of Engineering Thermodynamics, University of Kaiserslautern, Kaiserslautern, Germany
| | - Katrin Stöbener
- Department for Optimization, Fraunhofer Institute for Industrial Mathematics, Kaiserslautern, Germany
| | - Martin Horsch
- Department of Mechanical and Process Engineering, Laboratory of Engineering Thermodynamics, University of Kaiserslautern, Kaiserslautern, Germany
| | - Hans Hasse
- Department of Mechanical and Process Engineering, Laboratory of Engineering Thermodynamics, University of Kaiserslautern, Kaiserslautern, Germany
| |
Collapse
|
17
|
Goel H, Butler CL, Windom ZW, Rai N. Vapor Liquid Equilibria of Hydrofluorocarbons Using Dispersion-Corrected and Nonlocal Density Functionals. J Chem Theory Comput 2016; 12:3295-304. [PMID: 27295451 DOI: 10.1021/acs.jctc.6b00305] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent developments in dispersion corrected and nonlocal density functionals are aimed at accurately capturing dispersion interactions, a key shortcoming of local and semilocal approximations of density functional theory. These functionals have shown significant promise for dimers and small clusters of molecules as well as crystalline materials. However, their efficacy for predicting vapor liquid equilibria is largely unexplored. In this work, we examine the accuracy of dispersion-corrected and nonlocal van der Waals functionals by computing the vapor liquid coexistence curves (VLCCs) of hydrofluoromethanes. Our results indicate that the PBE-D3 functional performs significantly better in predicting saturated liquid densities than the rVV10 functional. With the PBE-D3 functional, we also find that as the number of fluorine atoms increase in the molecule, the accuracy of saturated liquid density prediction improves as well. All the functionals significantly underpredict the saturated vapor densities, which also result in an underprediction of saturated vapor pressure of all compounds. Despite the differences in the bulk liquid densities, the local microstructures of the liquid CFH3 and CF2H2 are relatively insensitive to the density functional employed. For CF3H, however, rVV10 predicts slightly more structured liquid than the PBE-D3 functional.
Collapse
Affiliation(s)
- Himanshu Goel
- Dave C. Swalm School of Chemical Engineering and Center for Advanced Vehicular Systems, Mississippi State University , Mississippi State 39762, Mississippi, United States
| | - Charles L Butler
- Dave C. Swalm School of Chemical Engineering and Center for Advanced Vehicular Systems, Mississippi State University , Mississippi State 39762, Mississippi, United States.,East Mississippi Community College, Scooba 39358, Mississippi, United States
| | - Zachary W Windom
- Dave C. Swalm School of Chemical Engineering and Center for Advanced Vehicular Systems, Mississippi State University , Mississippi State 39762, Mississippi, United States
| | - Neeraj Rai
- Dave C. Swalm School of Chemical Engineering and Center for Advanced Vehicular Systems, Mississippi State University , Mississippi State 39762, Mississippi, United States
| |
Collapse
|
18
|
Mausbach P, Köster A, Rutkai G, Thol M, Vrabec J. Comparative study of the Grüneisen parameter for 28 pure fluids. J Chem Phys 2016; 144:244505. [DOI: 10.1063/1.4954282] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
19
|
Werth S, Horsch M, Hasse H. Surface tension of the two center Lennard-Jones plus point dipole fluid. J Chem Phys 2016; 144:054702. [DOI: 10.1063/1.4940966] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Stephan Werth
- Laboratory of Engineering Thermodynamics, Department of Mechanical and Process Engineering, University of Kaiserslautern, Erwin-Schrödinger-Str. 44, 67663 Kaiserslautern, Germany
| | - Martin Horsch
- Laboratory of Engineering Thermodynamics, Department of Mechanical and Process Engineering, University of Kaiserslautern, Erwin-Schrödinger-Str. 44, 67663 Kaiserslautern, Germany
| | - Hans Hasse
- Laboratory of Engineering Thermodynamics, Department of Mechanical and Process Engineering, University of Kaiserslautern, Erwin-Schrödinger-Str. 44, 67663 Kaiserslautern, Germany
| |
Collapse
|
20
|
Hülsmann M, Kirschner KN, Krämer A, Heinrich DD, Krämer-Fuhrmann O, Reith D. Optimizing Molecular Models Through Force-Field Parameterization via the Efficient Combination of Modular Program Packages. FOUNDATIONS OF MOLECULAR MODELING AND SIMULATION 2016. [DOI: 10.1007/978-981-10-1128-3_4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
21
|
Excess properties of non-ideal binary mixtures containing water, methanol and ethanol by molecular simulation. J Mol Liq 2015. [DOI: 10.1016/j.molliq.2015.08.058] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
22
|
Hemmen A, Gross J. Transferable Anisotropic United-Atom Force Field Based on the Mie Potential for Phase Equilibrium Calculations: n-Alkanes and n-Olefins. J Phys Chem B 2015; 119:11695-707. [DOI: 10.1021/acs.jpcb.5b01354] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrea Hemmen
- Institute
of Thermodynamics
and Thermal Process Engineering, University of Stuttgart, Pfaffenwaldring
9, 70569 Stuttgart, Germany
| | - Joachim Gross
- Institute
of Thermodynamics
and Thermal Process Engineering, University of Stuttgart, Pfaffenwaldring
9, 70569 Stuttgart, Germany
| |
Collapse
|
23
|
|
24
|
Werth S, Stöbener K, Klein P, Küfer KH, Horsch M, Hasse H. Molecular modelling and simulation of the surface tension of real quadrupolar fluids. Chem Eng Sci 2015. [DOI: 10.1016/j.ces.2014.08.035] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
25
|
Müller EA, Jackson G. Force-Field Parameters from the SAFT-γ Equation of State for Use in Coarse-Grained Molecular Simulations. Annu Rev Chem Biomol Eng 2014; 5:405-27. [DOI: 10.1146/annurev-chembioeng-061312-103314] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A description of fluid systems with molecular-based algebraic equations of state (EoSs) and by direct molecular simulation is common practice in chemical engineering and the physical sciences, but the two approaches are rarely closely coupled. The key for an integrated representation is through a well-defined force field and Hamiltonian at the molecular level. In developing coarse-grained intermolecular potential functions for the fluid state, one typically starts with a detailed, bottom-up quantum-mechanical or atomic-level description and then integrates out the unwanted degrees of freedom using a variety of techniques; an iterative heuristic simulation procedure is then used to refine the parameters of the model. By contrast, with a top-down technique, one can use an accurate EoS to link the macroscopic properties of the fluid and the force-field parameters. We discuss the latest developments in a top-down representation of fluids, with a particular focus on a group-contribution formulation of the statistical associating fluid theory (SAFT-γ). The accurate SAFT-γ EoS is used to estimate the parameters of the Mie force field, which can then be used with confidence in direct molecular simulations to obtain thermodynamic, structural, interfacial, and dynamical properties that are otherwise inaccessible from the EoS. This is exemplified for several prototypical fluids and mixtures, including carbon dioxide, hydrocarbons, perfluorohydrocarbons, and aqueous surfactants.
Collapse
Affiliation(s)
- Erich A. Müller
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - George Jackson
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| |
Collapse
|
26
|
Werth S, Rutkai G, Vrabec J, Horsch M, Hasse H. Long-range correction for multi-site Lennard-Jones models and planar interfaces. Mol Phys 2013. [DOI: 10.1080/00268976.2013.861086] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
27
|
SpaGrOW—A Derivative-Free Optimization Scheme for Intermolecular Force Field Parameters Based on Sparse Grid Methods. ENTROPY 2013. [DOI: 10.3390/e15093640] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
28
|
Rutkai G, Thol M, Lustig R, Span R, Vrabec J. Communication: Fundamental equation of state correlation with hybrid data sets. J Chem Phys 2013; 139:041102. [DOI: 10.1063/1.4817203] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
|
29
|
|
30
|
Fischer M, Hoffmann F, Fröba M. Metal–organic frameworks and related materials for hydrogen purification: Interplay of pore size and pore wall polarity. RSC Adv 2012. [DOI: 10.1039/c2ra01239a] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
|
31
|
Engin C, Vrabec J, Hasse H. On the difference between a point multipole and an equivalent linear arrangement of point charges in force field models for vapour–liquid equilibria; partial charge based models for 59 real fluids. Mol Phys 2011. [DOI: 10.1080/00268976.2011.601604] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
32
|
Do H, Wheatley RJ, Hirst JD. Molecular simulation of the binary mixture of 1–1–1–2–tetrafluoroethane and carbon dioxide. Phys Chem Chem Phys 2011; 13:15708-13. [DOI: 10.1039/c1cp21419e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
33
|
Thermodynamic Properties for Applications in Chemical Industry via Classical Force Fields. MULTISCALE MOLECULAR METHODS IN APPLIED CHEMISTRY 2011; 307:201-49. [DOI: 10.1007/128_2011_164] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
34
|
Hülsmann M, Müller TJ, Ködderman T, Reith D. Automated force field optimisation of small molecules using a gradient-based workflow package. MOLECULAR SIMULATION 2010. [DOI: 10.1080/08927022.2010.513974] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
35
|
Do H, Wheatley RJ, Hirst JD. Microscopic structure of liquid 1-1-1-2-tetrafluoroethane (R134a) from Monte Carlo simulation. Phys Chem Chem Phys 2010; 12:13266-72. [PMID: 20830386 DOI: 10.1039/c0cp00620c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1-1-1-2-tetrafluoroethane (R134a) is one of the most commonly used refrigerants. Its thermophysical properties are important for evaluating the performance of refrigeration cycles. These can be obtained via computer simulation, with an insight into the microscopic structure of the liquid, which is not accessible to experiment. In this paper, vapour-liquid equilibrium properties of R134a and its liquid microscopic structure are investigated using coupled-decoupled configurational-bias Monte Carlo simulation in the Gibbs ensemble, with a recent potential [J. Phys. Chem. B 2009, 113, 178]. We find that the simulations agree well with the experimental data, except at the vicinity of the critical region. Liquid R134a packs like liquid argon, with a coordination number in the first solvation shell of 12 at 260 K. The nearest neighbours prefer to be localized in three different spaces around the central molecule, in such a manner that the dipole moments are in a parallel alignment. Analysis of the pair interaction energy shows clear association of R134a molecules, but no evidence for C-HF type hydrogen bonding is found. The above findings should be of relevance to a broad range of fluoroalkanes.
Collapse
Affiliation(s)
- Hainam Do
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | | | | |
Collapse
|
36
|
Raabe G, Maginn EJ. A Force Field for 3,3,3-Fluoro-1-propenes, Including HFO-1234yf. J Phys Chem B 2010; 114:10133-42. [DOI: 10.1021/jp102534z] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Gabriele Raabe
- Institut für Thermodynamik, Technische Universität Braunschweig, Hans-Sommer-Str. 5, 38106 Braunschweig, Germany, and Department of Chemical and Biomolecular Engineering, University of Notre Dame, 182 Fitzpatrick Hall, Notre Dame, Indiana 46556-5637
| | - Edward J. Maginn
- Institut für Thermodynamik, Technische Universität Braunschweig, Hans-Sommer-Str. 5, 38106 Braunschweig, Germany, and Department of Chemical and Biomolecular Engineering, University of Notre Dame, 182 Fitzpatrick Hall, Notre Dame, Indiana 46556-5637
| |
Collapse
|
37
|
Merker T, Engin C, Vrabec J, Hasse H. Molecular model for carbon dioxide optimized to vapor-liquid equilibria. J Chem Phys 2010; 132:234512. [DOI: 10.1063/1.3434530] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
|
38
|
Firanescu G, Signorell R. Predicting the Influence of Shape, Size, and Internal Structure of CO Aerosol Particles on Their Infrared Spectra. J Phys Chem B 2009; 113:6366-77. [DOI: 10.1021/jp8101767] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- George Firanescu
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Ruth Signorell
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| |
Collapse
|
39
|
Lago S, Gámez F, Cortada M, Merkling PJ, Garzón B. Influence of the Displacement out of the Center of Mass and Nonaxiality of the Dipole on the Thermodynamics of Liquids Composed of Linear Dipole Molecules. J Phys Chem B 2008; 112:8069-75. [DOI: 10.1021/jp801680z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. Lago
- Dpt. Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Ctra. de Utrera Km. 1, Seville 41013, Spain, and Dpt. Física Aplicada, Fisicoquímica y Óptica Facultad de Farmacia, Universidad San Pablo CEU, Urb. Montepríncipe, Boadilla del Monte, 28668 Madrid, Spain
| | - F. Gámez
- Dpt. Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Ctra. de Utrera Km. 1, Seville 41013, Spain, and Dpt. Física Aplicada, Fisicoquímica y Óptica Facultad de Farmacia, Universidad San Pablo CEU, Urb. Montepríncipe, Boadilla del Monte, 28668 Madrid, Spain
| | - M. Cortada
- Dpt. Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Ctra. de Utrera Km. 1, Seville 41013, Spain, and Dpt. Física Aplicada, Fisicoquímica y Óptica Facultad de Farmacia, Universidad San Pablo CEU, Urb. Montepríncipe, Boadilla del Monte, 28668 Madrid, Spain
| | - P. J. Merkling
- Dpt. Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Ctra. de Utrera Km. 1, Seville 41013, Spain, and Dpt. Física Aplicada, Fisicoquímica y Óptica Facultad de Farmacia, Universidad San Pablo CEU, Urb. Montepríncipe, Boadilla del Monte, 28668 Madrid, Spain
| | - B. Garzón
- Dpt. Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Ctra. de Utrera Km. 1, Seville 41013, Spain, and Dpt. Física Aplicada, Fisicoquímica y Óptica Facultad de Farmacia, Universidad San Pablo CEU, Urb. Montepríncipe, Boadilla del Monte, 28668 Madrid, Spain
| |
Collapse
|
40
|
|
41
|
The role of higher CO-multipole moments in understanding the dynamics of photodissociated carbonmonoxide in myoglobin. Biophys J 2008; 94:2505-15. [PMID: 18178640 DOI: 10.1529/biophysj.107.120519] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The influence of electrostatic multipole moments up to hexadecapole on the dynamics of photodissociated carbon monoxide (CO) in myoglobin is investigated. The CO electrostatic potential is expressed as an expansion into atomic multipole moments of increasing order up to octopole which are obtained from a distributed multipole analysis. Three models with increasingly accurate molecular multipoles (accurate quadrupole, octopole, and hexadecapole moments, respectively) are developed and used in molecular dynamics simulations. All models with a fluctuating quadrupole moment correctly describe the location of the B-state whereas the sign of the octopole moment differentiates between the Fe...CO and Fe...OC orientation. For the infrared spectrum of photodissociated CO, considerable differences between the three electrostatic models are found. The most detailed electrostatic model correctly reproduces the splitting, shift, and width of the CO spectrum in the B-state. From an analysis of the trajectories, the spectroscopic B(1) and B(2) states are assigned to the Fe...CO and Fe...OC substates, respectively.
Collapse
|
42
|
Vrabec J, Gross J. Vapor−Liquid Equilibria Simulation and an Equation of State Contribution for Dipole−Quadrupole Interactions. J Phys Chem B 2007; 112:51-60. [DOI: 10.1021/jp072619u] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jadran Vrabec
- Institut für Technische Thermodynamik und Thermische Verfahrenstechnik, Universität Stuttgart, Pfaffenwaldring 9, 70550 Stuttgart, Germany, and Engineering Thermodynamics, Delft University of Technology, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
| | - Joachim Gross
- Institut für Technische Thermodynamik und Thermische Verfahrenstechnik, Universität Stuttgart, Pfaffenwaldring 9, 70550 Stuttgart, Germany, and Engineering Thermodynamics, Delft University of Technology, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
| |
Collapse
|
43
|
|
44
|
Peguin RPS, Selvam P, da Rocha SRP. Microscopic and thermodynamic properties of the HFA134a-water interface: atomistic computer simulations and tensiometry under pressure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:8826-30. [PMID: 17014124 DOI: 10.1021/la0608157] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
A combined computational and experimental approach is used to determine the interfacial thermodynamic and structural properties of the liquid 1,1,1,2-tetrafluoroethane (HFA134a)-vapor and liquid HFA134a-water (HFA134a|W) interfaces at 298 K and saturation pressure. Molecular dynamics (MD) computer simulations reveal a stable interface between HFA134a and water. The "10-90" interfacial thickness is comparable with those typically reported for organic-water systems. The interfacial tension of the HFA134a|W interface obtained from the pressure tensor analysis of the MD trajectory is in good agreement with the experimental value determined using in situ high-pressure tensiometry. These results indicate that the potential models utilized are capable of describing the intermolecular interactions between these two fluids. The tension of the HFA134a|W interface is significantly lower than those typically observed for conventional oil-water interfaces and similar to that of the compressed CO(2)-water interface, observed at moderate CO(2) pressures. The MD and tensiometric results are also compared and contrasted with the HFA134a|W and chlorofluorocarbon-water tension values estimated from a parametric relationship. This represents the first report of the interfacial and microscopic properties of the (propellant) hydrofluoroalkanes (HFA)|W interface. The results presented here are of relevance in the design of surfactants capable of forming and stabilizing water-in-HFA microemulsions. Reverse aqueous microemulsions in HFA-based pressurized metered-dose inhalers are candidate formulations for the systemic delivery of biomolecules to and through the lungs.
Collapse
Affiliation(s)
- Robson P S Peguin
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, USA
| | | | | |
Collapse
|
45
|
Meng L, Duan YY. Site–site potential function and second virial coefficients for linear molecules. Mol Phys 2006. [DOI: 10.1080/00268970600867338] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
46
|
Grimm C, Kandratsenka A, Wagener P, Zerbs J, Schroeder J. Photoinduced Isomerization Kinetics of Diiodomethane in Supercritical Fluid Solution: Local Density Effects. J Phys Chem A 2006; 110:3320-9. [PMID: 16509658 DOI: 10.1021/jp055608e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The density dependence of diiodomethane photoinduced isomerization in supercritical (sc) CO2, CHF3, and C2H6 was investigated by transient absorption spectroscopy, covering a fluid density range from 0.7 to 2.5 (in reduced units). The solvent-caged photoproduct iso-diiodomethane is formed even at the lowest density, and its yield increases about 4-fold over the whole range. At the same time, isomer formation rate constants increase by roughly an order of magnitude and show little variation between CO2, C2H6, and CHF3. Furthermore, the formation rate constant decreases significantly with increasing excitation energy. We propose an isomer formation mechanism involving a rapidly established preequilibrium between a solvent-caged iodine atom-methyliodide radical pair and a loosely bound iodine-methyliodide radical complex, from which the reaction subsequently proceeds to the isomer. The latter step seems to be controlled by collisional stabilization of the initially hot radical moiety, as the formation rate constant increases linearly with sc solvent viscosity. The model predicts a quadratic dependence of relative isomer yield on fluid density. A corresponding correlation is found with the local fluid density, calculated via solute-solvent radial distribution functions obtained from molecular dynamics (MD) simulations.
Collapse
Affiliation(s)
- Christian Grimm
- Institut für Physikalische Chemie, Universität Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany
| | | | | | | | | |
Collapse
|