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Tanis I, Brown D, Neyertz S, Vaidya M, Ballaguet JP, Duval S, Bahamdan A. A Molecular Dynamics Study of Single-Gas and Mixed-Gas N 2 and CH 4 Transport in Triptycene-Based Polyimide Membranes. Polymers (Basel) 2023; 15:3811. [PMID: 37765665 PMCID: PMC10535442 DOI: 10.3390/polym15183811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/04/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
Fluorinated polyimides incorporated with triptycene units have gained growing attention over the last decade since they present potentially interesting selectivities and a higher free volume with respect to their triptycene-free counterparts. This work examines the transport of single-gas and mixed-gas N2 and CH4 in the triptycene-based 6FDA-BAPT homopolyimide and in a block 15,000 g mol-1/15,000 g mol-1 6FDA-mPDA/BAPT copolyimide by using molecular dynamics (MD) simulations. The void-space analyses reveal that, while the free volume consists of small-to-medium holes in the 6FDA-BAPT homopolyimide, there are more medium-to-large holes in the 6FDA-mPDA/BAPT copolyimide. The single-gas sorption isotherms for N2 and CH4 over the 0-70 bar range at 338.5 K show that both gases are more soluble in the block copolyimide, with a higher affinity for methane. CH4 favours sites with the most favourable energetic interactions, while N2 probes more sites in the matrices. The volume swellings remain limited since neither N2 nor CH4 plasticise penetrants. The transport of a binary-gas 2:1 CH4/N2 mixture is also examined in both polyimides under operating conditions similar to those used in current natural gas processing, i.e., at 65.5 bar and 338.5 K. In the mixed-gas simulations, the solubility selectivities in favour of CH4 are enhanced similarly in both matrices. Although diffusion is higher in 6FDA-BAPT/6FDA-mPDA, the diffusion selectivities are also close. Both triptycene-based polyimides under study favour, to a similar extent, the transport of methane over that of nitrogen under the conditions studied.
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Affiliation(s)
- Ioannis Tanis
- Univ. Savoie Mont Blanc, Univ. Grenoble Alpes, CNRS, Grenoble INP, LEPMI, 38000 Grenoble, France; (D.B.); (S.N.)
| | - David Brown
- Univ. Savoie Mont Blanc, Univ. Grenoble Alpes, CNRS, Grenoble INP, LEPMI, 38000 Grenoble, France; (D.B.); (S.N.)
| | - Sylvie Neyertz
- Univ. Savoie Mont Blanc, Univ. Grenoble Alpes, CNRS, Grenoble INP, LEPMI, 38000 Grenoble, France; (D.B.); (S.N.)
| | - Milind Vaidya
- Saudi Aramco, Research & Development Center, P.O. Box 62, Dhahran 31311, Saudi Arabia; (M.V.); (J.-P.B.); (S.D.); (A.B.)
| | - Jean-Pierre Ballaguet
- Saudi Aramco, Research & Development Center, P.O. Box 62, Dhahran 31311, Saudi Arabia; (M.V.); (J.-P.B.); (S.D.); (A.B.)
| | - Sebastien Duval
- Saudi Aramco, Research & Development Center, P.O. Box 62, Dhahran 31311, Saudi Arabia; (M.V.); (J.-P.B.); (S.D.); (A.B.)
| | - Ahmad Bahamdan
- Saudi Aramco, Research & Development Center, P.O. Box 62, Dhahran 31311, Saudi Arabia; (M.V.); (J.-P.B.); (S.D.); (A.B.)
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Agles AA, Bourg IC. Structure-Thermodynamic Relationship of a Polysaccharide Gel (Alginate) as a Function of Water Content and Counterion Type (Na vs Ca). J Phys Chem B 2023; 127:1828-1841. [PMID: 36791328 PMCID: PMC10159261 DOI: 10.1021/acs.jpcb.2c07129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/31/2023] [Indexed: 02/17/2023]
Abstract
Biofilms are the predominant mode of microbial life on Earth, and so a deep understanding of microbial communities─and their impacts on environmental processes─requires a firm understanding of biofilm properties. Because of the importance of biofilms to their microbial inhabitants, microbes have evolved different ways of engineering and reconfiguring the matrix of extracellular polymeric substances (EPS) that constitute the main non-living component of biofilms. This ability makes it difficult to distinguish between the biotic and abiotic origins of biofilm properties. An important route toward establishing this distinction has been the study of simplified models of the EPS matrix. This study builds on such efforts by using atomistic simulations to predict the nanoscale (≤10 nm scale) structure of a model EPS matrix and the sensitivity of this structure to interpolymer interactions and water content. To accomplish this, we use replica exchange molecular dynamics (REMD) simulations to generate all-atom configurations of ten 3.4 kDa alginate polymers at a range of water contents and Ca-Na ratios. Simulated systems are solvated with explicitly modeled water molecules, which allows us to capture the discrete structure of the hydrating water and to examine the thermodynamic stability of water in the gels as they are progressively dehydrated. Our primary findings are that (i) the structure of the hydrogels is highly sensitive to the identity of the charge-compensating cations, (ii) the thermodynamics of water within the gels (specific enthalpy and free energy) are, surprisingly, only weakly sensitive to cation identity, and (iii) predictions of the differential enthalpy and free energy of hydration include a short-ranged enthalpic term that promotes hydration and a longer-ranged (presumably entropic) term that promotes dehydration, where short and long ranges refer to distances shorter or longer than ∼0.6 nm between alginate strands.
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Affiliation(s)
- Avery A. Agles
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Ian C. Bourg
- Department
of Civil and Environmental Engineering and High Meadows Environmental
Institute, Princeton University, Princeton, New Jersey 08544, United States
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Ricci E, Minelli M, De Angelis MG. Modelling Sorption and Transport of Gases in Polymeric Membranes across Different Scales: A Review. MEMBRANES 2022; 12:857. [PMID: 36135877 PMCID: PMC9502097 DOI: 10.3390/membranes12090857] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/24/2022] [Accepted: 08/27/2022] [Indexed: 06/02/2023]
Abstract
Professor Giulio C. Sarti has provided outstanding contributions to the modelling of fluid sorption and transport in polymeric materials, with a special eye on industrial applications such as membrane separation, due to his Chemical Engineering background. He was the co-creator of innovative theories such as the Non-Equilibrium Theory for Glassy Polymers (NET-GP), a flexible tool to estimate the solubility of pure and mixed fluids in a wide range of polymers, and of the Standard Transport Model (STM) for estimating membrane permeability and selectivity. In this review, inspired by his rigorous and original approach to representing membrane fundamentals, we provide an overview of the most significant and up-to-date modeling tools available to estimate the main properties governing polymeric membranes in fluid separation, namely solubility and diffusivity. The paper is not meant to be comprehensive, but it focuses on those contributions that are most relevant or that show the potential to be relevant in the future. We do not restrict our view to the field of macroscopic modelling, which was the main playground of professor Sarti, but also devote our attention to Molecular and Multiscale Hierarchical Modeling. This work proposes a critical evaluation of the different approaches considered, along with their limitations and potentiality.
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Affiliation(s)
- Eleonora Ricci
- Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), Alma Mater Studiorum—University of Bologna, 40126 Bologna, Italy
| | - Matteo Minelli
- Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), Alma Mater Studiorum—University of Bologna, 40126 Bologna, Italy
| | - Maria Grazia De Angelis
- Institute for Materials and Processes, School of Engineering, University of Edinburgh, Edinburgh EH9 3FB, UK
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Voyiatzis E, Stroeks A. Atomistic Modeling of Hydrogen and Oxygen Solubility in Semicrystalline PA-6 and HDPE Materials. J Phys Chem B 2022; 126:6102-6111. [PMID: 35921684 DOI: 10.1021/acs.jpcb.2c02854] [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
Hydrogen is a clean and sustainable energy carrier which plays a major role in the transition of the global energy market to a less fossil fuel dependent future. Polymer-based materials are crucial in the production, storage, transportation, and energy extraction of hydrogen. More insights in the hydrogen-polymers interactions are required to guide material design and product development, especially for hydrogen solubility in polymers, which is crucial in many applications. The current study aims at rationalizing the determining factors of hydrogen solubility in two relevant polymers: polyamide-6 (PA-6) and high density polyethylene (HDPE). Based on atomistic molecular dynamics simulations and experimental data, we have reached several conclusions related to hydrogen and oxygen solubility in these two polymers. The crystal phases of PA-6 and HDPE are impenetrable to hydrogen and oxygen at elevated pressures, despite the small molecular size of hydrogen and oxygen. The practical implication for gas barrier applications is that polymer crystals act as impermeable obstacles and gas migration takes place primarily in the amorphous phase. Experimental hydrogen and oxygen solubilities in PA-6 and HDPE at elevated pressures can be predicted in a semiquantitative manner by molecular simulations. The discrepancies between experimental and predicted values could be attributed to neglect of the effect of crystal regions on the amorphous polymer domains. Although hydrogen is smaller than oxygen, it has been experimentally observed that hydrogen has a lower solubility in PA-6 and HDPE than oxygen. This observation has been confirmed by molecular simulations and attributed to the more favorable energetic interactions of oxygen with PA-6 and PE than of hydrogen. These interactions dominate the solubility behavior over the distribution of the accessible volume in the polymers.
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Affiliation(s)
| | - Alexander Stroeks
- DSM Engineering Materials, Urmonderbaan 22, 6167 RD Geleen, The Netherlands
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Tanis I, Brown D, Neyertz S, Vaidya M, Ballaguet JP, Duval S, Bahamdan A. Single-gas and mixed-gas permeation of N 2/CH 4 in thermally-rearranged TR-PBO membranes and their 6FDA-bisAPAF polyimide precursor studied by molecular dynamics simulations. Phys Chem Chem Phys 2022; 24:18667-18683. [PMID: 35894847 DOI: 10.1039/d1cp05511a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
High-performance polymers with polybenzoxazole (PBO) structures, formed via thermal rearrangement (TR) of aromatic polyimide precursors, have been developed for gas separation applications. The present work compares the transport of N2 and CH4 in a 6FDA-bisAPAF polyimide precursor and in its TR-PBO derivative using molecular dynamics (MD) simulations. The modelling closely mimicked the experimental approach by transforming a 6FDA-bisAPAF atomistic model into its corresponding TR-PBO structure via a specific algorithm. The densities and void spaces of both precursor and TR polymers were found to compare well to experimental data. An iterative technique was used to obtain the single-gas sorption isotherms of N2 and CH4 at 338.5 K in both polymers over a range of feed pressures up to and exceeding 65 bar. CH4 was systematically found to be more soluble than N2. Solubilities in both matrices were quite similar with those in TR-PBO being slightly higher due to its larger fraction of significant volume. Volume dilation analyses confirmed a higher resistance to plasticization for TR-PBO. Extended single-gas N2 and CH4 simulations and 2 : 1 binary CH4/N2 mixed-gas simulations were then conducted in both matrices at 338.5 K and at a pressure of ∼65 bar corresponding to natural gas processing conditions. Mixed-gas sorption was modelled using a modification of the aforementioned iterative method, which fixed the pressure and iterated to convergence the number of molecules of each type of penetrant. The gas diffusion coefficients were estimated using the Trajectory-Extending Kinetic Monte Carlo (TEKMC) procedure. As found experimentally, significantly higher diffusivities and permeabilities were observed in the TR polymer, which led to a slightly lower ideal N2/CH4 permselectivity for TR-PBO (∼2.6) when compared to its 6FDA-bisAPAF precursor (∼3.8). However, both models showed a reduced N2/CH4 separation efficiency under 2 : 1 binary CH4/N2 mixed-gas conditions bordering on the loss of selectivity. For 6FDA-bisAPAF, both permeabilities decreased in the mixed-gas case, but more for N2 than for CH4. For TR-PBO, the permeability of the faster N2 decreased while the permeability of the slower CH4 increased under mixed-gas conditions. This confirms that single-gas simulations are not sufficient for the prediction of the actual mixed-gas permselectivity behaviour in such polymers.
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Affiliation(s)
- Ioannis Tanis
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, Grenoble INP (Institute of Engineering and Management Univ. Grenoble Alpes), LEPMI, 38000 Grenoble, France.
| | - David Brown
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, Grenoble INP (Institute of Engineering and Management Univ. Grenoble Alpes), LEPMI, 38000 Grenoble, France.
| | - Sylvie Neyertz
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, Grenoble INP (Institute of Engineering and Management Univ. Grenoble Alpes), LEPMI, 38000 Grenoble, France.
| | - Milind Vaidya
- Saudi Aramco, Research & Development Center, Po. Box 62, Dhahran 31311, Saudi Arabia
| | - Jean-Pierre Ballaguet
- Saudi Aramco, Research & Development Center, Po. Box 62, Dhahran 31311, Saudi Arabia
| | - Sebastien Duval
- Saudi Aramco, Research & Development Center, Po. Box 62, Dhahran 31311, Saudi Arabia
| | - Ahmad Bahamdan
- Saudi Aramco, Research & Development Center, Po. Box 62, Dhahran 31311, Saudi Arabia
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Molecular Characterization of Membrane Gas Separation under Very High Temperatures and Pressure: Single- and Mixed-Gas CO2/CH4 and CO2/N2 Permselectivities in Hybrid Networks. MEMBRANES 2022; 12:membranes12050526. [PMID: 35629852 PMCID: PMC9143592 DOI: 10.3390/membranes12050526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/04/2022] [Accepted: 05/05/2022] [Indexed: 02/06/2023]
Abstract
This work illustrates the potential of using atomistic molecular dynamics (MD) and grand-canonical Monte Carlo (GCMC) simulations prior to experiments in order to pre-screen candidate membrane structures for gas separation, under harsh conditions of temperature and pressure. It compares at 300 °C and 400 °C the CO2/CH4 and CO2/N2 sieving properties of a series of hybrid networks based on inorganic silsesquioxanes hyper-cross-linked with small organic PMDA or 6FDA imides. The inorganic precursors are the octa(aminopropyl)silsesquioxane (POSS), which degrades above 300 °C, and the octa(aminophenyl)silsesquioxane (OAPS), which has three possible meta, para or ortho isomers and is expected to resist well above 400 °C. As such, the polyPOSS-imide networks were tested at 300 °C only, while the polyOAPS-imide networks were tested at both 300 °C and 400 °C. The feed gas pressure was set to 60 bar in all the simulations. The morphologies and densities of the pure model networks at 300 °C and 400 °C are strongly dependent on their precursors, with the amount of significant free volume ranging from ~2% to ~20%. Since measurements at high temperatures and pressures are difficult to carry out in a laboratory, six isomer-specific polyOAPS-imides and two polyPOSS-imides were simulated in order to assess their N2, CH4 and CO2 permselectivities under such harsh conditions. The models were first analyzed under single-gas conditions, but to be closer to the real processes, the networks that maintained CO2/CH4 and CO2/N2 ideal permselectivities above 2 were also tested with binary-gas 90%/10% CH4/CO2 and N2/CO2 feeds. At very high temperatures, the single-gas solubility coefficients vary in the same order as their critical temperatures, but the differences between the penetrants are attenuated and the plasticizing effect of CO2 is strongly reduced. The single-gas diffusion coefficients correlate well with the amount of available free volume in the matrices. Some OAPS-based networks exhibit a nanoporous behavior, while the others are less permeable and show higher ideal permselectivities. Four of the networks were further tested under mixed-gas conditions. The solubility coefficient improved for CO2, while the diffusion selectivity remained similar for the CO2/CH4 pair and disappeared for the CO2/N2 pair. The real separation factor is, thus, mostly governed by the solubility. Two polyOAPS-imide networks, i.e., the polyorthoOAPS-PMDA and the polymetaOAPS-6FDA, seem to be able to maintain their CO2/CH4 and CO2/N2 sieving abilities above 2 at 400 °C. These are outstanding performances for polymer-based membranes, and consequently, it is important to be able to produce isomer-specific polyOAPS-imides for use as gas separation membranes under harsh conditions.
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Neyertz S, Brown D, Salimi S, Radmanesh F, Benes NE. Molecular characterization of polyOAPS-imide isomer hyper-cross-linked membranes: Free-volume morphologies and sorption isotherms for CH4 and CO2. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2021.119531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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8
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Mollahosseini A, Abdelrasoul A. Molecular dynamics simulation for membrane separation and porous materials: A current state of art review. J Mol Graph Model 2021; 107:107947. [PMID: 34126546 DOI: 10.1016/j.jmgm.2021.107947] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/13/2021] [Accepted: 05/17/2021] [Indexed: 01/29/2023]
Abstract
Computational frameworks have been under specific attention within the last two decades. Molecular Dynamics (MD) simulations, identical to the other computational approaches, try to address the unknown question, lighten the dark areas of unanswered questions, to achieve probable explanations and solutions. Owing to their complex microporous structure on one side and the intricate biochemical nature of various materials used in the structure, separative membrane materials possess peculiar degrees of complications. More notably, as nanocomposite materials are often integrated into separative membranes, thin-film nanocomposites and porous separative nanocomposite materials could possess an additional level of complexity with regard to the nanoscale interactions brought to the structure. This critical review intends to cover the recent methods used to assess membranes and membrane materials. Incorporation of MD in membrane technology-related fields such as desalination, fuel cell-based energy production, blood purification through hemodialysis, etc., were briefly covered. Accordingly, this review could be used to understand the current extent of MD applications for separative membranes. The review could also be used as a guideline to use the proper MD implementation within the related fields.
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Affiliation(s)
- Arash Mollahosseini
- Department of Chemical and Biological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan, S7N 5A9, Canada
| | - Amira Abdelrasoul
- Department of Chemical and Biological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan, S7N 5A9, Canada; Division of Biomedical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan, S7N 5A9, Canada.
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9
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Single- and mixed-gas sorption in large-scale molecular models of glassy bulk polymers. Competitive sorption of a binary CH4/N2 and a ternary CH4/N2/CO2 mixture in a polyimide membrane. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2020.118478] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Vergadou N, Theodorou DN. Molecular Modeling Investigations of Sorption and Diffusion of Small Molecules in Glassy Polymers. MEMBRANES 2019; 9:E98. [PMID: 31398889 PMCID: PMC6723301 DOI: 10.3390/membranes9080098] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/22/2019] [Accepted: 07/23/2019] [Indexed: 11/16/2022]
Abstract
With a wide range of applications, from energy and environmental engineering, such as in gas separations and water purification, to biomedical engineering and packaging, glassy polymeric materials remain in the core of novel membrane and state-of the art barrier technologies. This review focuses on molecular simulation methodologies implemented for the study of sorption and diffusion of small molecules in dense glassy polymeric systems. Basic concepts are introduced and systematic methods for the generation of realistic polymer configurations are briefly presented. Challenges related to the long length and time scale phenomena that govern the permeation process in the glassy polymer matrix are described and molecular simulation approaches developed to address the multiscale problem at hand are discussed.
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Affiliation(s)
- Niki Vergadou
- Molecular Thermodynamics and Modelling of Materials Laboratory, Institute of Nanoscience and Nanotechnology, National Center for Scientific Research Demokritos, Aghia Paraskevi Attikis, GR-15310 Athens, Greece.
| | - Doros N Theodorou
- School of Chemical Engineering, National Technical University of Athens, GR 15780 Athens, Greece
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Brown D, Neyertz S, Raaijmakers MJ, Benes NE. Sorption and permeation of gases in hyper-cross-linked hybrid poly(POSS-imide) networks: An in silico study. J Memb Sci 2019. [DOI: 10.1016/j.memsci.2019.01.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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12
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Hörstermann H, Hentschke R, Amkreutz M, Hoffmann M, Wirts-Rütters M. Predicting water sorption and volume swelling in dense polymer systems via computer simulation. J Phys Chem B 2010; 114:17013-24. [PMID: 21141921 DOI: 10.1021/jp105210y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Atomistic model structures of amorphous polyamide 6 (PA-6) and of an adhesive system consisting of the diglycidyl ether of bisphenol A (DGEBA) as epoxy resin and isophorone diamine (IPD) as a curing agent are generated. For the adhesive, we use a new approach for the generation of the cross-linked polymer networks. It takes into account the chemical reaction kinetics of the curing reaction and, therefore, results in more realistic network structures. On the basis of the corresponding model structures, the equilibrium water content and the swelling ratio of amorphous PA-6 and of the DGEBA+IPD networks are calculated via computer simulation for different thermodynamic conditions. A hybrid method is used combining the molecular dynamics technique with an accelerated test particle insertion method. The results are in reasonable agreement with experiments and, in the case of the PA-6 system, with results obtained via other computer simulation methods.
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Affiliation(s)
- Henning Hörstermann
- Fachbereich Mathematik und Naturwissenschaften, Bergische Universität, D-42097 Wuppertal, Germany
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Pandiyan S, Brown D, Neyertz S, van der Vegt NFA. Carbon Dioxide Solubility in Three Fluorinated Polyimides Studied by Molecular Dynamics Simulations. Macromolecules 2010. [DOI: 10.1021/ma902507d] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Sudharsan Pandiyan
- LMOPS-UMR CNRS 5041, University of Savoie, Bât IUT, 73376 Le Bourget-du-Lac Cedex, France
- Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - David Brown
- LMOPS-UMR CNRS 5041, University of Savoie, Bât IUT, 73376 Le Bourget-du-Lac Cedex, France
| | - Sylvie Neyertz
- LMOPS-UMR CNRS 5041, University of Savoie, Bât IUT, 73376 Le Bourget-du-Lac Cedex, France
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14
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Marque G, Neyertz S, Verdu J, Prunier V, Brown D. Molecular Dynamics Simulation Study of Water in Amorphous Kapton. Macromolecules 2008. [DOI: 10.1021/ma702173j] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Grégory Marque
- LMOPS, UMR CNRS 5041, Université de Savoie, Bâtiment IUT, 73376 Le Bourget-du-Lac, France, LIM, UMR CNRS 8006, ENSAM, 151 Boulevard de l’Hôpital, 75013 Paris, France, and EDF R&D, Site des Renardières, 77818 Moret-sur-Loing, France
| | - Sylvie Neyertz
- LMOPS, UMR CNRS 5041, Université de Savoie, Bâtiment IUT, 73376 Le Bourget-du-Lac, France, LIM, UMR CNRS 8006, ENSAM, 151 Boulevard de l’Hôpital, 75013 Paris, France, and EDF R&D, Site des Renardières, 77818 Moret-sur-Loing, France
| | - Jacques Verdu
- LMOPS, UMR CNRS 5041, Université de Savoie, Bâtiment IUT, 73376 Le Bourget-du-Lac, France, LIM, UMR CNRS 8006, ENSAM, 151 Boulevard de l’Hôpital, 75013 Paris, France, and EDF R&D, Site des Renardières, 77818 Moret-sur-Loing, France
| | - Valéry Prunier
- LMOPS, UMR CNRS 5041, Université de Savoie, Bâtiment IUT, 73376 Le Bourget-du-Lac, France, LIM, UMR CNRS 8006, ENSAM, 151 Boulevard de l’Hôpital, 75013 Paris, France, and EDF R&D, Site des Renardières, 77818 Moret-sur-Loing, France
| | - David Brown
- LMOPS, UMR CNRS 5041, Université de Savoie, Bâtiment IUT, 73376 Le Bourget-du-Lac, France, LIM, UMR CNRS 8006, ENSAM, 151 Boulevard de l’Hôpital, 75013 Paris, France, and EDF R&D, Site des Renardières, 77818 Moret-sur-Loing, France
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15
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Neimark AV, Vishnyakov A. A simulation method for the calculation of chemical potentials in small, inhomogeneous, and dense systems. J Chem Phys 2005; 122:234108. [PMID: 16008431 DOI: 10.1063/1.1931663] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a modification of the gauge cell Monte Carlo simulation method [A. V. Neimark and A. Vishnyakov, Phys. Rev. E 62, 4611 (2000)] designed for chemical potential calculations in small confined inhomogeneous systems. To measure the chemical potential, the system under study is set in chemical equilibrium with the gauge cell, which represents a finite volume reservoir of ideal particles. The system and the gauge cell are immersed into the thermal bath of a given temperature. The size of the gauge cell controls the level of density fluctuations in the system. The chemical potential is rigorously calculated from the equilibrium distribution of particles between the system cell and the gauge cell and does not depend on the gauge cell size. This scheme, which we call a mesoscopic canonical ensemble, bridges the gap between the canonical and the grand canonical ensembles, which are known to be inconsistent for small systems. The ideal gas gauge cell method is illustrated with Monte Carlo simulations of Lennard-Jones fluid confined to spherical pores of different sizes. Special attention is paid to the case of extreme confinement of several molecular diameters in cross section where the inconsistency between the canonical ensemble and the grand canonical ensemble is most pronounced. For sufficiently large systems, the chemical potential can be reliably determined from the mean density in the gauge cell as it was implied in the original gauge cell method. The method is applied to study the transition from supercritical adsorption to subcritical capillary condensation, which is observed in nanoporous materials as the pore size increases.
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Affiliation(s)
- Alexander V Neimark
- Center for Modeling and Characterization of Nanoporous Materials, Textile Research Institute (TRI)/Princeton, Princeton, New Jersey 08542, USA.
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