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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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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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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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Akbari S, Mosavian MTH, Moosavi F, Ahmadpour A. Does the addition of a heteropoly acid change the water percolation threshold of PFSA membranes? Phys Chem Chem Phys 2019; 21:25080-25089. [PMID: 31690914 DOI: 10.1039/c9cp04432a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A large system containing heteropoly acids (HPAs) and Nafion® 117 was simulated and studied to verify whether the additive particles affect the formation of the water percolating network or not. Two structures of HPA particles were considered as dopants, i.e. H9AlW6O24 and H3PW12O40. The SAXS simulation revealed that HPA particle addition to the membrane matrix leads to an increased order in the abundance and size of the hydrophilic region beside an expansion of the distance between the ionic domains. The morphological assessment shows that the hydrophilic phase domains in the HPA-doped Nafion® were spaced further apart than in the undoped membrane. These results show that adding HPA particles to the PFSA membrane reduces the so-called dead-pockets and makes the water channels more interconnected. For undoped Nafion®, the so-called percolating hydration level (λp) was 5.63. In other words, according to these results, approximately 8 wt% of water molecules are required to establish a spanning water network. The H9AlW6O24 and H3PW12O40 particles directly influence the morphology of water clusters and reduce by 10.12% and 17.41% the required hydration level to reach the percolation threshold, respectively.
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Affiliation(s)
- Saeed Akbari
- Chemical Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.
| | | | - Fatemeh Moosavi
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Ali Ahmadpour
- Chemical Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.
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