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Zhang Z, Cui R, Jiang X, Yu C, Zhou Y. Effect of ionic groups on the morphology and transport properties in a novel perfluorinated ionomer containing sulfonic and phosphonic acid groups: a molecular dynamics study. Phys Chem Chem Phys 2024; 26:12806-12819. [PMID: 38619877 DOI: 10.1039/d4cp00962b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Combining the phosphonic acid group with the sulfonic acid group in PEMs has been shown to be an effective strategy for improving the fuel cell performance. However, the interplay of two different ionic groups and the resulting effect on the membrane properties have not been fully elucidated. Here, we used classical molecular dynamics simulation to investigate the morphologies, transport properties and effects of ionic groups in a novel perfluorinated PEM containing two ionic groups (PFSA-PFPA) in comparison to the corresponding homopolymers. Phase separations between hydrophilic and hydrophobic domains are confirmed in these PEMs and result from the evolution of water clusters formed around the ionic groups. The combination of both ionic groups brings a complicated morphological feature in PFSA-PFPA, with near-cylindrical aqueous domains of large length scales interconnected by tortuous domains of small sizes. And we found that the self-diffusion coefficients of water molecules are strongly related to morphologies, with the water transport in PFSA-PFPA lying between two analogous homopolymers. At the molecular level, we found that the sulfonic and phosphonic acid groups have distinct effects on the coordination behaviors and the dynamics of water molecules and hydronium ions. Strong electrostatic interactions lead to compact coordination structures and sluggish dynamics of hydronium ions around phosphonic acid groups, which determine the morphological evolution and transport properties in PFSA-PFPA. Our study affords insights into the relationship between molecular characteristics and transport properties bridged by phase-separated morphologies in a novel PEM containing both sulfonic acid and phosphonic acid groups, which deepens the understanding of the interplay between two ionic groups and may inspire the rational design of high-performance PEMs.
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Affiliation(s)
- Zongwei Zhang
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
| | - Rui Cui
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
| | - Xuesong Jiang
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
- Key Laboratory of Green and High-end Utilization of Salt Lake Resources, Chinese Academy of Sciences, China
| | - Chunyang Yu
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
- Key Laboratory of Green and High-end Utilization of Salt Lake Resources, Chinese Academy of Sciences, China
| | - Yongfeng Zhou
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
- Key Laboratory of Green and High-end Utilization of Salt Lake Resources, Chinese Academy of Sciences, China
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2
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Letsau T, Mabuchi T, Msomi PF. Molecular Dynamics Study on the Effect of Cyclic Conducting Moieties on Poly(2,6-dimethyl-1,4-phenylene oxide) Anion Exchange Membranes. ACS OMEGA 2023; 8:48711-48718. [PMID: 38162796 PMCID: PMC10753574 DOI: 10.1021/acsomega.3c05291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 11/02/2023] [Accepted: 11/24/2023] [Indexed: 01/03/2024]
Abstract
We investigate PPO quaternized with different azoles (five-membered heterocyclic compounds) with a different odd number of Nitrogen atoms (1N-pyrrole, 3N-1,2,3-triazole, and 5N-pentazole) to form pyrrolium-PPO(py-PPO), 1,2,3,-triazolium-PPO(tri-PPO) and pentazolium-PPO(pen-PPO) AEMs, using molecular dynamics (MD) simulations to compare and evaluate their OH- transport via the vehicular mechanism. OH- diffusivity at the hydration level λ = 12 is 3.10 × 10-10 m2/s, 1.92 × 10-10 m2/s m2/s, and 1.91 × 10-10 m2/s for py-PPO, tri-PPO, and pen-PPO, respectively. This trend is due to the shorter distance between adjacent groups of py-PPO (7.5 Å) leading to an efficient hydroxide transport than tri-PPO (7.8 Å) and pen-PPO (8.1 Å) at λ = 12. Also, this trend is justified by the smaller average number of clusters for py-PPO (1.2), smaller than tri-PPO(2.0), and pen-PPO (1.5) at λ = 12, which suggests better connectivity and hence better conductivity.
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Affiliation(s)
- Thabakgolo
T. Letsau
- Department
of Chemical Science, University of Johannesburg, PO Box 17011, Doornfontein, 2028Johannesburg ,South Africa
- Research
Centre for Synthesis and Catalysis, Department of Chemical Science, University of Johannesburg, PO Box 17011, Doornfontein, 2028Johannesburg ,South Africa
| | - Takuya Mabuchi
- Frontier
Research Institute of Interdisciplinary Sciences, Tohoku University, Sendai ,Miyagi9808577, Japan
- Institute
of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Phumlani F. Msomi
- Department
of Chemical Science, University of Johannesburg, PO Box 17011, Doornfontein, 2028Johannesburg ,South Africa
- Research
Centre for Synthesis and Catalysis, Department of Chemical Science, University of Johannesburg, PO Box 17011, Doornfontein, 2028Johannesburg ,South Africa
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3
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Hemmasi E, Tohidian M, Makki H. Morphology and Transport Study of Acid-Base Blend Proton Exchange Membranes by Molecular Simulations: Case of Chitosan/Nafion. J Phys Chem B 2023; 127:10624-10635. [PMID: 38037344 PMCID: PMC10726362 DOI: 10.1021/acs.jpcb.3c05332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/28/2023] [Accepted: 11/20/2023] [Indexed: 12/02/2023]
Abstract
Blending a basic polymer (e.g., chitosan) with Nafion can modify some membrane properties in direct methanol fuel cell applications, e.g., controlling methanol crossover, by regulating the morphology of hydrophilic channels. Unraveling the mechanisms by which the channel morphology is modified is essential to formulate design strategies for acid-base blend membrane development. Thus, we use molecular simulations to analyze the morphological features of a blend membrane (at 75/25 chitosan/Nafion wt %), i.e., (i) water/polymer phase organizations, (ii) number and size of water clusters, and (iii) quantitative morphological measures of hydrophilic channels, and compare them to the pure Nafion in a wide range of water contents. It is found that the affinity of water to different hydrophilic groups in the blend membrane can result in more distorted and dispersed hydrophilic phase and fewer bulk water-like features compared to pure Nafion. Also, the width of the hydrophilic network bottleneck, i.e., pore limiting diameter (PLD), is found to be almost five times smaller for the blend membrane compared to Nafion at their maximum water contents. Moreover, by changing the chitosan/Nafion weight ratio from 75/25 to 0/100, we show that as Nafion content increases, all channel morphological characteristics alter monotonically except PLD. This is mainly due to the strong acid-base interactions between Nafion and chitosan, which hinder the monotonic growth of PLD. Interestingly, water and methanol diffusion coefficients are strongly correlated with PLD, suggesting that PLD can be used as a single parameter for tailoring the blending ratio for achieving the desired diffusion properties of acid-base membranes.
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Affiliation(s)
- Ehsan Hemmasi
- Department
of Polymer and Color Engineering, Amirkabir
University of Technology, 424 Hafez Avenue, Tehran 59163-4311, Iran
| | - Mahdi Tohidian
- Department
of Polymer and Color Engineering, Amirkabir
University of Technology, 424 Hafez Avenue, Tehran 59163-4311, Iran
| | - Hesam Makki
- Department
of Chemistry and Materials Innovation Factory, University of Liverpool, Liverpool L69 7ZD, U.K.
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4
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Safronova EY, Lysova AA, Voropaeva DY, Yaroslavtsev AB. Approaches to the Modification of Perfluorosulfonic Acid Membranes. MEMBRANES 2023; 13:721. [PMID: 37623782 PMCID: PMC10456953 DOI: 10.3390/membranes13080721] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/01/2023] [Accepted: 08/05/2023] [Indexed: 08/26/2023]
Abstract
Polymer ion-exchange membranes are featured in a variety of modern technologies including separation, concentration and purification of gases and liquids, chemical and electrochemical synthesis, and hydrogen power generation. In addition to transport properties, the strength, elasticity, and chemical stability of such materials are important characteristics for practical applications. Perfluorosulfonic acid (PFSA) membranes are characterized by an optimal combination of these properties. Today, one of the most well-known practical applications of PFSA membranes is the development of fuel cells. Some disadvantages of PFSA membranes, such as low conductivity at low humidity and high temperature limit their application. The approaches to optimization of properties are modification of commercial PFSA membranes and polymers by incorporation of different additive or pretreatment. This review summarizes the approaches to their modification, which will allow the creation of materials with a different set of functional properties, differing in ion transport (first of all proton conductivity) and selectivity, based on commercially available samples. These approaches include the use of different treatment techniques as well as the creation of hybrid materials containing dopant nanoparticles. Modification of the intrapore space of the membrane was shown to be a way of targeting the key functional properties of the membranes.
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Affiliation(s)
- Ekaterina Yu. Safronova
- Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninsky Avenue, 31, 119991 Moscow, Russia; (A.A.L.); (D.Y.V.); (A.B.Y.)
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5
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Parshina A, Yelnikova A, Safronova E, Kolganova T, Bobreshova O, Yaroslavtsev A. Potentiometric Sensor Arrays Based on Hybrid PFSA/CNTs Membranes for the Analysis of UV-Degraded Drugs. Polymers (Basel) 2023; 15:2682. [PMID: 37376327 DOI: 10.3390/polym15122682] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 06/10/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
The degradation of drugs is a substantial problem since it affects the safety and effectiveness of pharmaceutical products, as well as their influence on the environment. A novel system of three potentiometric cross-sensitive sensors (using the Donnan potential (DP) as an analytical signal) and a reference electrode was developed for the analysis of UV-degraded sulfacetamide drugs. The membranes for DP-sensors were prepared by a casting procedure from a dispersion of perfluorosulfonic acid (PFSA) polymer, containing carbon nanotubes (CNTs), whose surface was preliminarily modified with carboxyl, sulfonic acid, or (3-aminopropyl)trimethoxysilanol groups. A correlation between the sorption and transport properties of the hybrid membranes and cross-sensitivity of the DP-sensor to sulfacetamide, its degradation product, and inorganic ions was revealed. The analysis of the UV-degraded sulfacetamide drugs using the multisensory system based on hybrid membranes with optimized properties did not require a pre-separation of the components. The limits of detection of sulfacetamide, sulfanilamide, and sodium were 1.8 × 10-7, 5.8 × 10-7, and 1.8 × 10-7 M. The relative errors of the determination of the components of the UV-degraded sulfacetamide drugs were 2-3% (at 6-8% relative standard deviation). PFSA/CNT hybrid materials provided the stable work of the sensors for at least one year.
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Affiliation(s)
- Anna Parshina
- Department of Analytical Chemistry, Voronezh State University, 394018 Voronezh, Russia
| | - Anastasia Yelnikova
- Department of Analytical Chemistry, Voronezh State University, 394018 Voronezh, Russia
| | - Ekaterina Safronova
- Kurnakov Institute of General and Inorganic Chemistry RAS, 119991 Moscow, Russia
| | - Tatyana Kolganova
- Department of Analytical Chemistry, Voronezh State University, 394018 Voronezh, Russia
| | - Olga Bobreshova
- Department of Analytical Chemistry, Voronezh State University, 394018 Voronezh, Russia
| | - Andrey Yaroslavtsev
- Kurnakov Institute of General and Inorganic Chemistry RAS, 119991 Moscow, Russia
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6
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Hee Lee J, Hyun Kwon S, Kang H, Hye Lee J, Geol Lee S. Investigation of structural and transport properties of highly oxygen-permeable ionomer in polymer electrolyte membrane fuel cells using molecular dynamics simulations. J IND ENG CHEM 2023. [DOI: 10.1016/j.jiec.2023.03.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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7
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Cui R, Li S, Yu C, Zhou Y. The Evolution of Hydrogen Bond Network in Nafion via Molecular Dynamics Simulation. Macromolecules 2023. [DOI: 10.1021/acs.macromol.2c02106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Affiliation(s)
- Rui Cui
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Shanlong Li
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Chunyang Yu
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Yongfeng Zhou
- School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
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8
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Hei B, Pemberton JE, Schwartz SD. Classical Molecular Dynamics Simulation of Glyonic Liquids: Structural Insights and Relation to Conductive Properties. J Phys Chem B 2023; 127:921-931. [PMID: 36652632 PMCID: PMC9898233 DOI: 10.1021/acs.jpcb.2c07264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Rhamnolipids are biosurfactants that have obtained wide industrial and environmental interests with their biodegradability and great surface activity. Besides their important roles as surfactants, they are found to function as a new type of glycolipid-based protic ionic liquids (ILs)─glyonic liquids (GLs). GLs are reported to have impressive physicochemical properties, especially superionic conductivity, and it was reported in experiments that specific ion selections and the fraction of water content have a strong effect on the conductivity. Also, the shape of the conductivity curve as a function of water fraction in GLs is interesting with a sharp increase first and a long plateau. We related the conductivities to the three-dimensional (3D) networks composed of -OH inside the GLs utilizing classical molecular dynamics (MD) simulations. The amount and size of these networks vary with both ion species and water fractions. Before reaching the first hydration layer, the -OH networks with higher projection/box length ratios indicate better conductivity; after reaching the first hydration layer and forming continuous structures, the conductivity retains with more water molecules participating in the continuous networks. Therefore, networks are found to be a qualitative predictor of actual conductivity. This is explained by the analysis of the atomic structures, including radial distribution function, fraction free volume, anion conformations, and hydrogen bond occupancies, of GLs and their water mixtures under different chemical conditions.
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Affiliation(s)
- Bai Hei
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Jeanne E Pemberton
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Steven D Schwartz
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
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9
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Li G, Zhu Y, Guo Y, Mabuchi T, Li D, Huang S, Wang S, Sun H, Tokumasu T. Deep Learning to Reveal the Distribution and Diffusion of Water Molecules in Fuel Cell Catalyst Layers. ACS APPLIED MATERIALS & INTERFACES 2023; 15:5099-5108. [PMID: 36652634 DOI: 10.1021/acsami.2c17198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Water management in the catalyst layers (CLs) of proton-exchange membrane fuel cells is crucial for its commercialization and popularization. However, the high experimental or computational cost in obtaining water distribution and diffusion remains a bottleneck in the existing experimental methods and simulation algorithms, and further mechanistic exploration at the nanoscale is necessary. Herein, we integrate, for the first time, molecular dynamics simulation with our customized analysis framework based on a multiattribute point cloud dataset and an advanced deep learning network. This was achieved through our workflow that generates simulated transport data of water molecules in the CLs as the training and test dataset. Deep learning framework models the multibody solid-liquid system of CLs on a molecular scale and completes the mapping from the Pt/C substrate structure and Nafion aggregates to the density distribution and diffusion coefficient of water molecules. The prediction results are comprehensively analyzed and error evaluated, which reveals the highly anisotropic interaction landscape between 50,000 pairs of interacting nanoparticles and explains the structure and water transport property relationship in the hydrated Nafion film on the molecular scale. Compared to the conventional methods, the proposed deep learning framework shows computational cost efficiency, accuracy, and good visual display. Further, it has a generality potential to model macro- and microscopic mass transport in different components of fuel cells. Our framework is expected to make real-time predictions of the distribution and diffusion of water molecules in CLs as well as establish statistical significance in the structural optimization and design of CLs and other components of fuel cells.
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Affiliation(s)
- Gaoyang Li
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai980-8577, Japan
| | - Yonghong Zhu
- School of Chemical Engineering, Northwest University, Xi'an710069Shaanxi, China
| | - Yuting Guo
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai980-8577, Japan
| | - Takuya Mabuchi
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai980-8577, Japan
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi980-8577, Japan
| | - Dong Li
- School of Chemical Engineering, Northwest University, Xi'an710069Shaanxi, China
| | - Shengfeng Huang
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai980-8577, Japan
| | - Sirui Wang
- Graduate School of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba263-8522, Japan
| | - Haiyi Sun
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai980-8577, Japan
| | - Takashi Tokumasu
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai980-8577, Japan
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10
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Safronova EY, Voropaeva DY, Safronov DV, Stretton N, Parshina AV, Yaroslavtsev AB. Correlation between Nafion Morphology in Various Dispersion Liquids and Properties of the Cast Membranes. MEMBRANES 2022; 13:13. [PMID: 36676820 PMCID: PMC9862164 DOI: 10.3390/membranes13010013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 12/11/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
Nafion is a perfluorosulfonic acid polymer that is most commonly used in proton-exchange membrane fuel cells. The processes of pretreatment and formation of such membranes strongly affect their properties. In this work, dispersions of Nafion in various ionic forms and dispersing liquids (ethylene glycol, N,N-dimethylformamide, N-methyl-2-pyrrolidone and isopropyl alcohol-water mixtures in different ratios) were obtained and studied. Membranes fabricated by casting of the various dispersions were also studied. The effect of the nature of the dispersing liquid and the counterion on the properties of Nafion dispersions, the morphology of the polymer in the dispersions and the characteristics of the membranes obtained from them has been shown. Based on the overall results, it can be concluded that the use of perfluorosulfonic acid dispersions in aprotic polar solvents is advisable for obtaining membranes by the casting procedure. This is because it provides optimal polymer morphology in the dispersion, which leads to the formation of films with good selectivity, mechanical and transport properties. The performed investigations show the relationship between the composition of dispersions, the morphology of the polymer and the properties of the membranes formed from them by the casting procedure.
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Affiliation(s)
- Ekaterina Yu. Safronova
- N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Daria Yu. Voropaeva
- N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Dmitry V. Safronov
- N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Nastasia Stretton
- N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Anna V. Parshina
- Department of Analytical Chemistry, Voronezh State University, 394018 Voronezh, Russia
| | - Andrey B. Yaroslavtsev
- N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia
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11
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You J, Cheng X, Li H, Yin J, Yan X, Wei G, Shen S, Zhang J. Innovative Insight into O 2/N 2 Permeation Behavior through an Ionomer Film in Cathode Catalyst Layers of Polymer Electrolyte Membrane Fuel Cells. J Phys Chem Lett 2022; 13:11444-11453. [PMID: 36468972 DOI: 10.1021/acs.jpclett.2c03210] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
It is crucial to clarify the permeation behavior of O2 through the ionomer film for enhancing local O2 transport in cathodes of fuel cells. However, all existing studies mainly deal with pure O2 rather than air. Herein, the permeation behavior of the O2/N2 mixture through the ionomer film has been well explored in view of molecular bond length variations by molecular dynamics simulations. The bond lengths for O2 and N2 are shortened under a low hydration level when permeating through a dense layer with small free voids while no obvious change occurs at higher hydration. In the bulk ionomer region, O2 molecules residing in water domains are energetically unstable because the bond lengths deviate far from the equilibrium length; thus, O2 diffuses through the interfacial or hydrophobic regions. N2 molecules show similar properties with O2. This study provides a novel perspective on the permeation behavior of O2 and N2 through the ionomer film, which definitely benefits enhancing local O2 transport.
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Affiliation(s)
- Jiabin You
- Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, 200240Shanghai, China
| | - Xiaojing Cheng
- Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, 200240Shanghai, China
| | - Huiyuan Li
- Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, 200240Shanghai, China
| | - Jiewei Yin
- Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, 200240Shanghai, China
| | - Xiaohui Yan
- Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, 200240Shanghai, China
| | - Guanghua Wei
- SJTU-Paris Tech Elite Institute of Technology, Shanghai Jiao Tong University, 200240Shanghai, China
| | - Shuiyun Shen
- Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, 200240Shanghai, China
| | - Junliang Zhang
- Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, 200240Shanghai, China
- MOE Key Laboratory of Power & Machinery Engineering, Shanghai Jiao Tong University, 200240Shanghai, China
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12
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On the Properties of Nafion Membranes Recast from Dispersion in N-Methyl-2-Pyrrolidone. Polymers (Basel) 2022; 14:polym14235275. [PMID: 36501669 PMCID: PMC9737685 DOI: 10.3390/polym14235275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/25/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Perfluorosulfonic acid Nafion membranes are widely used as an electrolyte in electrolysis processes and in fuel cells. Changing the preparation and pretreatment conditions of Nafion membranes allows for the optimization of their properties. In this work, a Nafion-NMP membrane with a higher conductivity than the commercial Nafion® 212 membrane (11.5 and 8.7 mS∙cm-1 in contact with water at t = 30 °C) and a comparable hydrogen permeability was obtained by casting from a Nafion dispersion in N-methyl-2-pyrrolidone. Since the ion-exchange capacity and the water uptake of these membranes are similar, it can be assumed that the increase in conductivity is the result of optimizing the Nafion-NMP microstructure by improving the connectivity of the pores and channels system. This leads to a 27% increase in the capacity of the membrane electrode assembly with the Nafion-NMP membrane compared to the Nafion® 212 membrane. Thus, the method of obtaining a Nafion membrane has a great influence on its properties and performance of fuel cells based on them.
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13
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Guo Y, Mabuchi T, Li G, Tokumasu T. Morphology Evolution and Adsorption Behavior of Ionomers from Solution to Pt/C Substrates. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yuting Guo
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Takuya Mabuchi
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Gaoyang Li
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Takashi Tokumasu
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
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14
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Mabuchi T. Revealing the Anticorrelation Behavior Mechanism between the Grotthuss and Vehicular Diffusions for Proton Transport in Concentrated Acid Solutions. J Phys Chem B 2022; 126:3319-3326. [PMID: 35468285 DOI: 10.1021/acs.jpcb.1c09742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this study, we performed reactive molecular dynamics simulations to characterize proton solvation and transport in concentrated hydrochloric acid solutions. The correlation contribution to the total proton mean square displacement is found to be negative for all acid concentrations, indicating the anticorrelation between the Grotthuss and vehicular diffusions. For the vehicular diffusion, the hydronium ions tend to move freely toward the lone pair side independent of acid concentrations, whereas for the Grotthuss diffusion, the proton hopping direction is limited to one of the hydrogen-bonded water molecules on the opposite side of the lone pair region, which are specifically oriented with respect to the neighboring hydronium ion at higher acid concentrations. This result is justified by our findings of the higher fraction of proton rattling with the single hopping event and longer hydrogen bond lifetimes at higher acid concentrations. However, the angular distribution for both the vehicular and Grotthuss diffusions is found to be rather broad and comparable for all acid concentrations, and thus, the anticorrelation shows a minimal dependence on the acid concentration. Our results reveal that the anticorrelation behavior between the vehicle and Grotthuss diffusions is attributed to the amphiphilic nature of hydronium ions and thus is independent of the acid concentrations in solutions.
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Affiliation(s)
- Takuya Mabuchi
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan.,Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
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Cui R, Li S, Yu C, Wang Y, Zhou Y. Understanding the mechanism of nitrogen transport in the perfluorinated sulfonic-acid hydrated membranes via molecular dynamics simulations. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2022.120328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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16
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Prediction of the adsorption properties of liquid at solid surfaces with molecular scale surface roughness via encoding-decoding convolutional neural networks. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118489] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Hu Y, Wang S, He Y, An L. Evaluation of proton transport and solvation effect in hydrated Nafion membrane with degradation. Phys Chem Chem Phys 2022; 24:29024-29033. [DOI: 10.1039/d2cp02817d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In proton exchange membrane fuel cells (PEMFCs), free radicals easily attack ionomers, resulting in membrane degradation.
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Affiliation(s)
- Yu Hu
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Shuai Wang
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Yurong He
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Liang An
- Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, China
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18
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Nanochannels and nanodroplets in polymer membranes controlling ionic transport. Curr Opin Colloid Interface Sci 2021. [DOI: 10.1016/j.cocis.2021.101501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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19
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Luque Di Salvo J, De Luca G, Cipollina A, Micale G. A full-atom multiscale modelling for sodium chloride diffusion in anion exchange membranes. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2021.119646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Mabuchi T, Nakajima K, Tokumasu T. Molecular Dynamics Study of Ion Transport in Polymer Electrolytes of All-Solid-State Li-Ion Batteries. MICROMACHINES 2021; 12:mi12091012. [PMID: 34577657 PMCID: PMC8467922 DOI: 10.3390/mi12091012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/30/2021] [Accepted: 08/05/2021] [Indexed: 01/15/2023]
Abstract
Atomistic analysis of the ion transport in polymer electrolytes for all-solid-state Li-ion batteries was performed using molecular dynamics simulations to investigate the relationship between Li-ion transport and polymer morphology. Polyethylene oxide (PEO) and poly(diethylene oxide-alt-oxymethylene), P(2EO-MO), were used as the electrolyte materials, and the effects of salt concentrations and polymer types on the ion transport properties were explored. The size and number of LiTFSI clusters were found to increase with increasing salt concentrations, leading to a decrease in ion diffusivity at high salt concentrations. The Li-ion transport mechanisms were further analyzed by calculating the inter/intra-hopping rate and distance at various ion concentrations in PEO and P(2EO-MO) polymers. While the balance between the rate and distance of inter-hopping was comparable for both PEO and P(2EO-MO), the intra-hopping rate and distance were found to be higher in PEO than in P(2EO-MO), leading to a higher diffusivity in PEO. The results of this study provide insights into the correlation between the nanoscopic structures of ion solvation and the dynamics of Li-ion transport in polymer electrolytes.
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Affiliation(s)
- Takuya Mabuchi
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai 980-8577, Miyagi, Japan
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai 980-8577, Miyagi, Japan; (K.N.); (T.T.)
- Correspondence: ; Tel.: +81-22-217-5292
| | - Koki Nakajima
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai 980-8577, Miyagi, Japan; (K.N.); (T.T.)
- Graduate School of Engineering, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai 980-8577, Miyagi, Japan
| | - Takashi Tokumasu
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai 980-8577, Miyagi, Japan; (K.N.); (T.T.)
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Wang W, Qu Z, Wang X, Zhang J. A Molecular Model of PEMFC Catalyst Layer: Simulation on Reactant Transport and Thermal Conduction. MEMBRANES 2021; 11:membranes11020148. [PMID: 33672648 PMCID: PMC7924188 DOI: 10.3390/membranes11020148] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/18/2021] [Accepted: 02/18/2021] [Indexed: 11/16/2022]
Abstract
Minimizing platinum (Pt) loading while reserving high reaction efficiency in the catalyst layer (CL) has been confirmed as one of the key issues in improving the performance and application of proton exchange membrane fuel cells (PEMFCs). To enhance the reaction efficiency of Pt catalyst in CL, the interfacial interactions in the three-phase interface, i.e., carbon, Pt, and ionomer should be first clarified. In this study, a molecular model containing carbon, Pt, and ionomer compositions is built and the radial distribution functions (RDFs), diffusion coefficient, water cluster morphology, and thermal conductivity are investigated after the equilibrium molecular dynamics (MD) and nonequilibrium MD simulations. The results indicate that increasing water content improves water aggregation and cluster interconnection, both of which benefit the transport of oxygen and proton in the CL. The growing amount of ionomer promotes proton transport but generates additional resistance to oxygen. Both the increase of water and ionomer improve the thermal conductivity of the C. The above-mentioned findings are expected to help design catalyst layers with optimized Pt content and enhanced reaction efficiency, and further improve the performance of PEMFCs.
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Mabuchi T, Huang SF, Tokumasu T. Influence of Ionomer Loading and Substrate Wettability on the Morphology of Ionomer Thin Films Using Coarse-Grained Solvent Evaporation Simulations. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01303] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Takuya Mabuchi
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Sheng-Feng Huang
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Takashi Tokumasu
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai, Miyagi 980-8577, Japan
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Giricheva NI, Ivanov SN, Ignatova AV, Fedorov MS, Girichev GV. The Effect of Intramolecular Hydrogen Bond Type on the Gas-Phase Deprotonation of ortho-Substituted Benzenesulfonic Acids. A Density Functional Theory Study. Molecules 2020; 25:E5806. [PMID: 33316963 PMCID: PMC7764180 DOI: 10.3390/molecules25245806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 11/30/2020] [Accepted: 12/07/2020] [Indexed: 12/01/2022] Open
Abstract
Structural factors have been identified that determine the gas-phase acidity of ortho-substituted benzenesulfonic acid, 2-XC6H4-SO3H, (X = -SO3H, -COOH, -NO2, -SO2F, -C≡N, -NH2, -CH3, -OCH3, -N(CH3)2, -OH). The DFT/B3LYP/cc-pVTZ method was used to perform conformational analysis and study the structural features of the molecular and deprotonated forms of these compounds. It has been shown that many of the conformers may contain anintramolecular hydrogen bond (IHB) between the sulfonic group and the substituent, and the sulfonic group can be an IHB donor or an acceptor. The Gibbs energies of gas-phase deprotonation ΔrG0298 (kJ mol-1) were calculated for all compounds. It has been set that in ortho-substituted benzenesulfonic acids, the formation of various types of IHB is possible, having a significant effect on the ΔrG0298 values of gas-phase deprotonation. If the -SO3H group is the IHB donor, then an ion without an IHB is formed upon deprotonation, and the deprotonation energy increases. If this group is an IHB acceptor, then a significant decrease in ΔrG0298 of gas-phase deprotonation is observed due to an increase in IHB strength and the A- anion additional stabilization. A proton donor ability comparative characteristic of the -SO3H group in the studied ortho-substituted benzenesulfonic acids is given, and the ΔrG0298 energies are compared with the corresponding values of ortho-substituted benzoic acids.
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Affiliation(s)
- Nina I. Giricheva
- Department of Fundamental and Applied Chemistry, Ivanovo State University, 153025 Ivanovo, Russia; (S.N.I.); (A.V.I.); (M.S.F.)
| | - Sergey N. Ivanov
- Department of Fundamental and Applied Chemistry, Ivanovo State University, 153025 Ivanovo, Russia; (S.N.I.); (A.V.I.); (M.S.F.)
| | - Anastasiya V. Ignatova
- Department of Fundamental and Applied Chemistry, Ivanovo State University, 153025 Ivanovo, Russia; (S.N.I.); (A.V.I.); (M.S.F.)
| | - Mikhail S. Fedorov
- Department of Fundamental and Applied Chemistry, Ivanovo State University, 153025 Ivanovo, Russia; (S.N.I.); (A.V.I.); (M.S.F.)
| | - Georgiy V. Girichev
- Department of Physics, Ivanovo State University of Chemistry and Technology, 153000 Ivanovo, Russia;
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Mabuchi T, Huang SF, Tokumasu T. Dispersion of Nafion Ionomer Aggregates in 1-Propanol/Water Solutions: Effects of Ionomer Concentration, Alcohol Content, and Salt Addition. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b02725] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Takuya Mabuchi
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai, Miyagi 980-8577, Japan
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Sheng-Feng Huang
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Takashi Tokumasu
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira Aoba-ku, Sendai, Miyagi 980-8577, Japan
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Mabuchi T, Huang S, Tokumasu T. Nafion Ionomer Dispersion in Mixtures of 1‐Propanol and Water Based on the Martini Coarse‐Grained Model. JOURNAL OF POLYMER SCIENCE 2020. [DOI: 10.1002/pol.20190101] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Takuya Mabuchi
- Frontier Research Institute for Interdisciplinary SciencesTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
- Institute of Fluid ScienceTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
| | - Sheng‐Feng Huang
- Institute of Fluid ScienceTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
| | - Takashi Tokumasu
- Institute of Fluid ScienceTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
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Kawai K, Mabuchi T, Tokumasu T. Molecular Dynamics Analysis of Proton Diffusivity in Hydrated Nafion Membranes Contaminated with Ferrous Ions. MACROMOL THEOR SIMUL 2019. [DOI: 10.1002/mats.201900047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Kiyoto Kawai
- Graduate School of EngineeringTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
| | - Takuya Mabuchi
- Frontier Research Institute for Interdisciplinary SciencesTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
- Institute of Fluid ScienceTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
| | - Takashi Tokumasu
- Institute of Fluid ScienceTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
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Fan L, Wu K, Tongsh C, Zhu M, Xie X, Jiao K. Mechanism of Water Content on the Electrochemical Surface Area of the Catalyst Layer in the Proton Exchange Membrane Fuel Cell. J Phys Chem Lett 2019; 10:6409-6413. [PMID: 31593468 DOI: 10.1021/acs.jpclett.9b02549] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Combined molecular dynamics (MD) simulation and experiment are adopted to gain the mechanism of water content on the electrochemical surface area (ECSA) of the catalyst layer in a proton exchange membrane fuel cell. The morphology of water domains in the catalyst layer has a strong impact on the ECSA via MD simulation. The morphology of the water domains is isolated water clusters at low water content, resulting in the poor ECSA due to the lack of proton transport paths. The transport paths of protons tend to be quickly established with increasing water content during the transition process of the morphology of water domains from isolated water clusters to the water channel network, thereby leading to the rapid increase of the ECSA. However, the slight increase of the ECSA at high water content mainly results from the improved contact area between water domains and Pt particle instead of the formation of new transport paths. In addition, the stronger binding of water molecules and the Pt particle at low temperature results in a higher ECSA.
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Affiliation(s)
- Linhao Fan
- State Key Laboratory of Engines , Tianjin University , 135 Yaguan Road , Tianjin , China , 300350
| | - Kangcheng Wu
- State Key Laboratory of Engines , Tianjin University , 135 Yaguan Road , Tianjin , China , 300350
| | - Chasen Tongsh
- State Key Laboratory of Engines , Tianjin University , 135 Yaguan Road , Tianjin , China , 300350
| | - Mengqian Zhu
- State Key Laboratory of Engines , Tianjin University , 135 Yaguan Road , Tianjin , China , 300350
| | - Xu Xie
- State Key Laboratory of Engines , Tianjin University , 135 Yaguan Road , Tianjin , China , 300350
| | - Kui Jiao
- State Key Laboratory of Engines , Tianjin University , 135 Yaguan Road , Tianjin , China , 300350
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Clark JA, Santiso EE, Frischknecht AL. Morphology and proton diffusion in a coarse-grained model of sulfonated poly(phenylenes). J Chem Phys 2019; 151:104901. [DOI: 10.1063/1.5116684] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
- Jennifer A. Clark
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Erik E. Santiso
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Amalie L. Frischknecht
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
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Wang R, Liu S, Wang L, Li M, Gao C. Understanding of Nanophase Separation and Hydrophilic Morphology in Nafion and SPEEK Membranes: A Combined Experimental and Theoretical Studies. NANOMATERIALS (BASEL, SWITZERLAND) 2019; 9:E869. [PMID: 31181646 PMCID: PMC6631217 DOI: 10.3390/nano9060869] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/02/2019] [Accepted: 06/03/2019] [Indexed: 01/12/2023]
Abstract
The understanding of the relationship between the chemical structure and the hydrophilic structure is crucial for the designing of high-performance PEMs. Comparative studies in typical Nafion and sulfonated poly (ether ether ketone) (SPEEK) were performed using a combined experimental and theoretical method. SPEEK showed suppressed fuel crossover and good mechanical property but low water uptake, weak phase separation, and inadequate proton conductivity. Molecular dynamics (MD) simulation approaches were employed to get a molecular-level understanding of the structure-property relationship of SPEEK and Nafion membranes. In SPEEK membranes, the local aggregation of hydrophilic clusters is worse, and much stronger electrostatic interaction between Os-Hh was verified, resulting in less delocalized free H3O+ and much lower DH3O+. In addition, the probability of H2O-H3O+ association varied with water content. Particularly, SPEEK exhibited much lower H9O4+ probability at various relative water contents, leading to lower structural diffusivity than Nafion. Eventually, SPEEK possessed low vehicular and structural diffusivities, which resulted in a low proton conductivity. The results indicated that the structure of hydrated hydronium complexes would deform to adapt the confining hydrophilic channels. The confinement effect on diffusion of H2O and H3O+ is influenced by the water content and the hydrophilic morphologies. This study provided a new insight into the exploration of high-performance membranes in fuel cell.
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Affiliation(s)
- Rujie Wang
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding 071003, China.
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
| | - Shanshan Liu
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding 071003, China.
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
| | - Lidong Wang
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding 071003, China.
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
| | - Ming Li
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding 071003, China.
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
| | - Chong Gao
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding 071003, China.
- MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
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Mabuchi T, Tokumasu T. Effects of water nanochannel diameter on proton transport in proton‐exchange membranes. ACTA ACUST UNITED AC 2019. [DOI: 10.1002/polb.24842] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Takuya Mabuchi
- Frontier Research Institute for Interdisciplinary SciencesTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
| | - Takashi Tokumasu
- Institute of Fluid ScienceTohoku University 2‐1‐1 Katahira Aoba‐ku, Sendai Miyagi 980‐8577 Japan
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Teixeira FC, de Sá AI, Teixeira APS, Rangel CM. Enhanced proton conductivity of Nafion-azolebisphosphonate membranes for PEM fuel cells. NEW J CHEM 2019. [DOI: 10.1039/c9nj03405f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Azolebisphosphonates were prepared and used as dopants to obtain new Nafion doped membranes, which exhibited higher proton conductivities than that of Nafion.
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Affiliation(s)
| | - Ana I. de Sá
- Laboratório Nacional de Energia e Geologia
- I.P
- 1649-038 Lisboa
- Portugal
| | - António P. S. Teixeira
- Departamento de Química
- ECT & Centro de Química de Évora
- IIFA
- Universidade de Évora
- 7000-671 Évora
| | - C. M. Rangel
- Laboratório Nacional de Energia e Geologia
- I.P
- 1649-038 Lisboa
- Portugal
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