1
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Dorenbos G. How fork-length asymmetry affects solvent connectivity and diffusion in grafted polymeric model membranes. J Chem Phys 2024; 160:064901. [PMID: 38341779 DOI: 10.1063/5.0193120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 01/15/2024] [Indexed: 02/13/2024] Open
Abstract
The hydrophilic pore morphology and solvent diffusion within model (amphiphilic) polymer membranes are simulated by dissipative particle dynamics (DPD). The polymers are composed of a backbone of 18 covalently bonded A beads to which at regular intervals side chains are attached. The side chains are composed of linear Ap chains (i.e., -A1-A2…Ap) from which two branches, [AsC] and [ArC], split off (s ≤ r). C beads serve as functionalized hydrophilic pendent sites. The branch lengths (s + 1 and r + 1) are varied. Five repeat unit designs (with general formula A3[Ap[AsC][ArC]]) are considered: A2[A3C][A3C] (symmetric branching), A2[A2C][A4C], A2[AC][A5C], A2[C][A6C] (highly asymmetric branching), and A4[AC][A3C]. The distribution of water (W) and W diffusion through nanophase segregated hydrophilic pores is studied. For similar primary length p, an increase in side chain symmetry favors hydrophilic pore connectivity and long-range water transport. C beads located on the longer [ArC] branches reveal the highest C bead mobility and are more strongly associated with water than the C beads on the shorter [AsC] branches. The connectivity of hydrophilic (W and W + C) phases through mapped replica of selected snapshots obtained from Monte Carlo tracer diffusion simulations is in line with trends found from the W bead diffusivities during DPD simulations. The diffusive pathways for protons (H+) in proton exchange membranes and for hydronium (OH-) in anion exchange membranes are the same as for solvents. Therefore, control of the side chain architecture is an interesting design parameter for optimizing membrane conductivities.
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Affiliation(s)
- G Dorenbos
- Private research, Sano 1107-2, Belle Crea 502, 410-1118 Susono, Japan
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2
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Dorenbos G. Simulated and Experimental Trends Regarding Water Uptake in Polymeric Electrolyte Membranes. J Phys Chem B 2023; 127:9630-9641. [PMID: 37882051 DOI: 10.1021/acs.jpcb.3c05309] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
Polymeric membranes in an anion or a proton exchange membrane fuel cell need sufficient hydration in order to provide a high hydroxide ion or proton conductivity. The water uptake for six model ionomer membranes, all of the same ion exchange capacity, is modeled by dissipative particle dynamics. The architectures cover three types of families that are of potential interest in fuel cell membrane research. All architectures consist of connected hydrophobic backbone A beads, to which side chains are grafted. For the type I family, the hydrophilic (functional) C beads are pendent on (amphiphilic) [AxC] side chains. The type II architecture contains both hydrophobic [A4] and short hydrophilic [C] side chains. For type III, the C beads are embedded along various locations within the [AxCAy] side chains (x + y = constant). For similar equilibrium time, the membrane water volume fraction increases with side chain length x for type I, and for type III, it increases with the distance x that C beads are separated from the backbone. Among the architectures (types I and III) for which the number of covalent C-A bonds are the same, the water uptake increases with the average number of A-A and A-C bonds (dpd springs) between A beads and the nearest C bead. A picture emerges in which for similar ion exchange capacity model membranes water uptake increases as a function of ⟨Nbondphob-phyl⟩.
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Affiliation(s)
- G Dorenbos
- Private Researcher, Belle Crea 502, 1107-2 Susono 410-1118, Japan
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3
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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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4
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Eskandari H, Paul DK, Young AP, Karan K. Humidity-Dependent Hydration and Proton Conductivity of PFSA Ionomer Thin Films at Fuel-Cell-Relevant Temperatures: Effect of Ionomer Equivalent Weight and Side-Chain Characteristics. ACS APPLIED MATERIALS & INTERFACES 2022; 14:50762-50772. [PMID: 36342365 DOI: 10.1021/acsami.2c12667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Studies on the hydration properties, proton conductivity, and water content of perfluorinated ionomer thin films at temperatures relevant to fuel cell operation temperatures (around 80 °C) and the effect of ionomer chemistry are scarce. In this work, we report the water content and proton conductivity properties of thin-film ionomers (30 nm) at 80 °C over a wide range of relative humidity (0-90%) for seven different ionomers differing in the side-chain structure, including the number of protogenic groups, with the equivalent weight ranging from 620 to 1100 g/mol of sulfonic acid. The results show that the acid content or equivalent weight of the ionomer is the strongest determinant of both the swelling and the proton conductivity of ionomer films at a given relative humidity. The molar water content (λ) of ionomer films normalized to the molar protogenic group is observed to be equivalent-weight-dependent, implying that the affinity for water is acid-content-dependent. At high relative humidity conditions (>70%) pertinent to fuel cell operations, the proton conductivity of low-equivalent-weight ionomers was higher than that of higher-equivalent-weight ionomers. However, upon correlating the proton conductivity with molar water content (λ), the differences reduce dramatically, highlighting that water content is the controlling factor for proton conduction. Significantly higher values of both water content and proton conductivity are observed at 80 °C compared to those at 30 °C, implying that room temperature data are not reliable for estimating ionomer properties in the fuel cell catalyst layer.
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Affiliation(s)
- Hamideh Eskandari
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, Calgary, AlbertaT2N 1N4, Canada
| | - Devproshad K Paul
- Ballard Power Systems Inc., 9000 Glenlyon Parkway, Burnaby, British ColumbiaV5J 5J8, Canada
| | - Alan P Young
- Ballard Power Systems Inc., 9000 Glenlyon Parkway, Burnaby, British ColumbiaV5J 5J8, Canada
| | - Kunal Karan
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, Calgary, AlbertaT2N 1N4, Canada
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5
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Abstract
Ion-containing polymers have continued to be an important research focus for several decades due to their use as an electrolyte in energy storage and conversion devices. Elucidation of connections between the mesoscopic structure and multiscale dynamics of the ions and solvent remains incompletely understood. Coarse-grained modeling provides an efficient approach for exploring the structural and dynamical properties of these soft materials. The unique physicochemical properties of such polymers are of broad interest. In this review, we summarize the current development and understanding of the structure-property relationship of ion-containing polymers and provide insights into the design of such materials determined from coarse-grained modeling and simulations accompanying significant advances in experimental strategies. We specifically concentrate on three types of ion-containing polymers: proton exchange membranes (PEMs), anion exchange membranes (AEMs), and polymerized ionic liquids (polyILs). We posit that insight into the similarities and differences in these materials will lead to guidance in the rational design of high-performance novel materials with improved properties for various power source technologies.
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Affiliation(s)
- Zhenghao Zhu
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Xubo Luo
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Stephen J Paddison
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
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6
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Wang J, Chen J, Xu Z, Yang X, Ramakrishna S, Liu Y. Mesoscale hydrated morphology of perfluorosulfonic acid membranes. J Appl Polym Sci 2022. [DOI: 10.1002/app.52275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jihao Wang
- Beijing Key Laboratory of Advanced Functional Polymer Composites, College of Materials Science and Engineering Beijing University of Chemical Technology Beijing China
| | - Jia Chen
- Beijing Key Laboratory of Advanced Functional Polymer Composites, College of Materials Science and Engineering Beijing University of Chemical Technology Beijing China
| | - Zhiyang Xu
- Beijing Key Laboratory of Advanced Functional Polymer Composites, College of Materials Science and Engineering Beijing University of Chemical Technology Beijing China
| | - Xiaozhen Yang
- State Key Laboratory of Polymer Physics and Chemistry Institute of Chemistry, Chinese Academy of Science Beijing China
| | - Seeram Ramakrishna
- Nanoscience and Nanotechnology Initiative National University of Singapore Singapore Singapore
| | - Yong Liu
- Beijing Key Laboratory of Advanced Functional Polymer Composites, College of Materials Science and Engineering Beijing University of Chemical Technology Beijing China
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7
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Guo W, Liu Q, Zhang L, Du J, Zhu X, Fung KY, Yu Y, Ng KM. Computer-Aided Design of a Perfluorinated Sulfonic Acid Proton Exchange Membrane Using Stochastic Optimization and Molecular Dynamic Method. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c03661] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Wenjing Guo
- Institute of Process Systems Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Qilei Liu
- Institute of Process Systems Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Lei Zhang
- Institute of Process Systems Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Jian Du
- Institute of Process Systems Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Xiuling Zhu
- State Key Lab of Fine Chemicals, Department of Polymer Science & Materials, Dalian University of Technology, Dalian 116024, China
| | - Ka Yip Fung
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, 999077 Hong Kong
| | - Yong Yu
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, 999077 Hong Kong
| | - Ka Ming Ng
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, 999077 Hong Kong
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8
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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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9
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Zhong W, Liu F, Wang C. Probing morphology and chemistry in complex soft materials with in situresonant soft x-ray scattering. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:313001. [PMID: 34140434 DOI: 10.1088/1361-648x/ac0194] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/14/2021] [Indexed: 06/12/2023]
Abstract
Small angle scattering methodologies have been evolving at fast pace over the past few decades due to the ever-increasing demands for more details on the complex nanostructures of multiphase and multicomponent soft materials like polymer assemblies and biomaterials. Currently, element-specific and contrast variation techniques such as resonant (elastic) soft/tender x-ray scattering, anomalous small angle x-ray scattering, and contrast-matching small angle neutron scattering, or combinations of above are routinely used to extract the chemical composition and spatial arrangement of constituent elements at multiple length scales and examine electronic ordering phenomena. Here we present some recent advances in selectively characterizing structural architectures of complex soft materials, which often contain multi-components with a wide range of length scales and multiple functionalities, where novel resonant scattering approaches have been demonstrated to decipher a higher level of structural complexity that correlates to functionality. With the advancement of machine learning and artificial intelligence assisted correlative analysis, high-throughput and autonomous experiments would open a new paradigm of material research. Further development of resonant x-ray scattering instrumentation with crossplatform sample environments will enable multimodalin situ/operando characterization of the system dynamics with much improved spatial and temporal resolution.
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Affiliation(s)
- Wenkai Zhong
- Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America
| | - Feng Liu
- Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Cheng Wang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America
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10
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Wang J, Xu Z, Chen J, Yang X, Ramakrishna S, Liu Y. Mesoscale Simulation on the Hydrated Morphologies of SPEEK Membrane. MACROMOL THEOR SIMUL 2021. [DOI: 10.1002/mats.202100006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jihao Wang
- Beijing Key Laboratory of Advanced Functional Polymer Composites College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 China
| | - Zhiyang Xu
- Beijing Key Laboratory of Advanced Functional Polymer Composites College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 China
| | - Jia Chen
- Beijing Key Laboratory of Advanced Functional Polymer Composites College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 China
| | - Xiaozhen Yang
- State Key Laboratory of Polymer Physics and Chemistry Institute of Chemistry Chinese Academy of Science Beijing 100190 China
| | - Seeram Ramakrishna
- Nanoscience and Nanotechnology Initiative National University of Singapore Singapore 11576 Singapore
| | - Yong Liu
- Beijing Key Laboratory of Advanced Functional Polymer Composites College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 China
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11
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Primachenko ON, Marinenko EA, Odinokov AS, Kononova SV, Kulvelis YV, Lebedev VT. State of the art and prospects in the development of proton‐conducting perfluorinated membranes with short side chains: A review. POLYM ADVAN TECHNOL 2020. [DOI: 10.1002/pat.5191] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Oleg N. Primachenko
- Laboratory of synthesis of high temperature resistant polymers Institute of Macromolecular Compounds of Russian Academy of Sciences Saint Petersburg Russia
| | - Elena A. Marinenko
- Laboratory of synthesis of high temperature resistant polymers Institute of Macromolecular Compounds of Russian Academy of Sciences Saint Petersburg Russia
| | - Alexey S. Odinokov
- Laboratory of synthesis of high temperature resistant polymers Institute of Macromolecular Compounds of Russian Academy of Sciences Saint Petersburg Russia
- Russian Research Center of Applied Chemistry Saint Petersburg Russia
| | - Svetlana V. Kononova
- Laboratory of synthesis of high temperature resistant polymers Institute of Macromolecular Compounds of Russian Academy of Sciences Saint Petersburg Russia
| | - Yuri V. Kulvelis
- Neutron research department Petersburg Nuclear Physics Institute, NRC “Kurchatov Institute” Gatchina Russia
| | - Vasily T. Lebedev
- Neutron research department Petersburg Nuclear Physics Institute, NRC “Kurchatov Institute” Gatchina Russia
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12
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Li T, Shen J, Chen G, Guo S, Xie G. Performance Comparison of Proton Exchange Membrane Fuel Cells with Nafion and Aquivion Perfluorosulfonic Acids with Different Equivalent Weights as the Electrode Binders. ACS OMEGA 2020; 5:17628-17636. [PMID: 32715248 PMCID: PMC7377320 DOI: 10.1021/acsomega.0c02110] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 06/23/2020] [Indexed: 06/07/2023]
Abstract
A perfluorosulfonic acid (PFSA) ionomer, used as the proton conductor in the catalyst layer, influences significantly the performance of proton exchange membrane fuel cell catalyst-coated membrane (CCM). In this paper, SSC-CCM is prepared by the SSC-PFSA (Aquivion, EW 720) ionomer, and the comparative sample (LSC-CCM) is based on the LSC-PFSA ionomer (Nafion, EW 1100). Compared with LSC-CCM, SSC-CCM shows higher porosity, larger electrochemical surface area (ECSA), and smaller high-frequency resistance. Polarization curves of SSC-CCM tested by the short stack show better performance than those of LSC-CCM, especially under the lower relative humidity operations. Moreover, the SSC-CCM outputs higher voltage and is more stable in the dynamic process with temperature continuously increasing under lower relative humidity operation. Such excellent performance of SSC-CCM is confirmed from the higher proton conductivity of SSC-PFSA under low relative humidity. These results indicate that the SSC-PFSA ionomer could be employed for the CCM catalyst layer under the operation conditions of low relative humidity and dynamic running for automotive applications.
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Affiliation(s)
- Ting Li
- The
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China
- Energy
Conversion R&D Center, Central Academy
of Dongfang Electric Corporation, Chengdu 611731, China
| | - Jiabin Shen
- The
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China
| | - Guangying Chen
- Energy
Conversion R&D Center, Central Academy
of Dongfang Electric Corporation, Chengdu 611731, China
| | - Shaoyun Guo
- The
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China
| | - Guangyou Xie
- Energy
Conversion R&D Center, Central Academy
of Dongfang Electric Corporation, Chengdu 611731, China
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13
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Kuo AT, Miyazaki Y, Jang C, Miyajima T, Urata S, Nielsen SO, Okazaki S, Shinoda W. Large-scale molecular dynamics simulation of perfluorosulfonic acid membranes: Remapping coarse-grained to all-atomistic simulations. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.121766] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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14
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Su GM, Cordova IA, Yandrasits MA, Lindell M, Feng J, Wang C, Kusoglu A. Chemical and Morphological Origins of Improved Ion Conductivity in Perfluoro Ionene Chain Extended Ionomers. J Am Chem Soc 2019; 141:13547-13561. [DOI: 10.1021/jacs.9b05322] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Gregory M. Su
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Isvar A. Cordova
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | | | | | - Jun Feng
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Cheng Wang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Ahmet Kusoglu
- Energy Conversion Group, Energy Technologies Area, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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15
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Coarse-grained study of the effect of hydrophobic side chain length on cluster size distributions and water diffusion in (amphiphilic-hydrophobic) multi-block co-polymer membranes. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.04.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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16
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Mesoscale modeling of sulfonated polyimides copolymer membranes: Effect of sequence distributions. J Memb Sci 2018. [DOI: 10.1016/j.memsci.2018.07.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Kim DJ, Park CH, Tocci E, Nam SY. Experimental and modeling study of blended membranes for direct methanol fuel cells. J Memb Sci 2018. [DOI: 10.1016/j.memsci.2018.07.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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18
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Vishnyakov A, Mao R, Lee MT, Neimark AV. Coarse-grained model of nanoscale segregation, water diffusion, and proton transport in Nafion membranes. J Chem Phys 2018; 148:024108. [PMID: 29331134 DOI: 10.1063/1.4997401] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a coarse-grained model of the acid form of Nafion membrane that explicitly includes proton transport. This model is based on a soft-core bead representation of the polymer implemented into the dissipative particle dynamics (DPD) simulation framework. The proton is introduced as a separate charged bead that forms dissociable Morse bonds with water beads. Morse bond formation and breakup artificially mimics the Grotthuss hopping mechanism of proton transport. The proposed DPD model is parameterized to account for the specifics of the conformations and flexibility of the Nafion backbone and sidechains; it treats electrostatic interactions in the smeared charge approximation. The simulation results qualitatively, and in many respects quantitatively, predict the specifics of nanoscale segregation in the hydrated Nafion membrane into hydrophobic and hydrophilic subphases, water diffusion, and proton mobility. As the hydration level increases, the hydrophilic subphase exhibits a percolation transition from a collection of isolated water clusters to a 3D network of pores filled with water embedded in the hydrophobic matrix. The segregated morphology is characterized in terms of the pore size distribution with the average size growing with hydration from ∼1 to ∼4 nm. Comparison of the predicted water diffusivity with the experimental data taken from different sources shows good agreement at high and moderate hydration and substantial deviation at low hydration, around and below the percolation threshold. This discrepancy is attributed to the dynamic percolation effects of formation and rupture of merging bridges between the water clusters, which become progressively important at low hydration, when the coarse-grained model is unable to mimic the fine structure of water network that includes singe molecule bridges. Selected simulations of water diffusion are performed for the alkali metal substituted membrane which demonstrate the effects of the counter-ions on membrane self-assembly and transport. The hydration dependence of the proton diffusivity reproduces semi-qualitatively the trend of the diverse experimental data, showing a sharp decrease around the percolation threshold. Overall, the proposed model opens up an opportunity to study self-assembly and water and proton transport in polyelectrolytes using computationally efficient DPD simulations, and, with further refinement, it may become a practical tool for theory informed design and optimization of perm-selective and ion-conducting membranes with improved properties.
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Affiliation(s)
- Aleksey Vishnyakov
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, New Jersey 08854-8058, USA
| | - Runfang Mao
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, New Jersey 08854-8058, USA
| | - Ming-Tsung Lee
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, New Jersey 08854-8058, USA
| | - Alexander V Neimark
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, New Jersey 08854-8058, USA
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19
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Vanya P, Sharman J, Elliott JA. Mesoscale simulations of confined Nafion thin films. J Chem Phys 2017; 147:214904. [PMID: 29221394 DOI: 10.1063/1.4996695] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- P. Vanya
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - J. Sharman
- Johnson Matthey Technology Centre, Blounts Court Road, Sonning Common, Reading RG4 9NH, United Kingdom
| | - J. A. Elliott
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
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20
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Doping proton transport channels in poly-electrolyte membranes with high acidic site density polymers. Eur Polym J 2017. [DOI: 10.1016/j.eurpolymj.2017.09.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Kuo AT, Okazaki S, Shinoda W. Transferable coarse-grained model for perfluorosulfonic acid polymer membranes. J Chem Phys 2017; 147:094904. [DOI: 10.1063/1.4986287] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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22
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Berrod Q, Hanot S, Guillermo A, Mossa S, Lyonnard S. Water sub-diffusion in membranes for fuel cells. Sci Rep 2017; 7:8326. [PMID: 28827621 PMCID: PMC5567110 DOI: 10.1038/s41598-017-08746-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 07/12/2017] [Indexed: 11/09/2022] Open
Abstract
We investigate the dynamics of water confined in soft ionic nano-assemblies, an issue critical for a general understanding of the multi-scale structure-function interplay in advanced materials. We focus in particular on hydrated perfluoro-sulfonic acid compounds employed as electrolytes in fuel cells. These materials form phase-separated morphologies that show outstanding proton-conducting properties, directly related to the state and dynamics of the absorbed water. We have quantified water motion and ion transport by combining Quasi Elastic Neutron Scattering, Pulsed Field Gradient Nuclear Magnetic Resonance, and Molecular Dynamics computer simulation. Effective water and ion diffusion coefficients have been determined together with their variation upon hydration at the relevant atomic, nanoscopic and macroscopic scales, providing a complete picture of transport. We demonstrate that confinement at the nanoscale and direct interaction with the charged interfaces produce anomalous sub-diffusion, due to a heterogeneous space-dependent dynamics within the ionic nanochannels. This is irrespective of the details of the chemistry of the hydrophobic confining matrix, confirming the statistical significance of our conclusions. Our findings turn out to indicate interesting connections and possibilities of cross-fertilization with other domains, including biophysics. They also establish fruitful correspondences with advanced topics in statistical mechanics, resulting in new possibilities for the analysis of Neutron scattering data.
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Affiliation(s)
- Quentin Berrod
- LLB, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191, Gif-sur-Yvette, France
- Lawrence Berkeley National Laboratory, Energy Storage Group, 94720, Berkeley, USA
| | - Samuel Hanot
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS, 20156 - 38042, Grenoble, France
- Unité de Bioinformatique Structurale, Institut Pasteur, Paris, France
- UMR 3528, CNRS, Paris, France
| | - Armel Guillermo
- Univ. Grenoble Alpes, CEA, CNRS, INAC, SYMMES, F-38000, Grenoble, France
| | - Stefano Mossa
- Univ. Grenoble Alpes, CEA, CNRS, INAC, SYMMES, F-38000, Grenoble, France.
| | - Sandrine Lyonnard
- Univ. Grenoble Alpes, CEA, CNRS, INAC, SYMMES, F-38000, Grenoble, France.
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Dorenbos G. Improving proton conduction pathways in di- and triblock copolymer membranes: Branched versus linear side chains. J Chem Phys 2017; 146:244909. [PMID: 28668060 DOI: 10.1063/1.4989487] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Phase separation within a series of polymer membranes in the presence of water is studied by dissipative particle dynamics. Each polymer contains hydrophobic A beads and hydrophilic C beads. Three parent architectures are constructed from a backbone composed of connected hydrophobic A beads to which short ([C]), long ([A3C]), or symmetrically branched A5[AC][AC] side chains spring off. Three di-block copolymer derivatives are constructed by covalently bonding an A30 block to each parent architecture. Also three tri-blocks with A15 blocks attached to both ends of each parent architecture are modeled. Monte Carlo tracer diffusion calculations through the water containing pores for 1226 morphologies reveal that water diffusion for parent architectures is slowest and diffusion through the di-blocks is fastest. Furthermore, diffusion increases with side chain length and is highest for branched side chains. This is explained by the increase of water pore size with 〈Nbond〉, which is the average number of bonds that A beads are separated from a nearest C bead. Optimization of 〈Nbond〉 within the amphiphilic parent architecture is expected to be essential in improving proton conduction in polymer electrolyte membranes.
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Affiliation(s)
- G Dorenbos
- 410-1118, sano 1107-2, Belle Crea 502, Susono, Japan
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24
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Sepehr F, Liu H, Luo X, Bae C, Tuckerman ME, Hickner MA, Paddison SJ. Mesoscale Simulations of Anion Exchange Membranes Based on Quaternary Ammonium Tethered Triblock Copolymers. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b00082] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Fatemeh Sepehr
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Hongjun Liu
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Xubo Luo
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Chulsung Bae
- Department
of Chemistry and Chemical Biology, New York State Center for Polymer
Synthesis, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Mark E. Tuckerman
- Department
of Chemistry, New York University, New York, New York 10003, United States
- Courant
Institute of Mathematical Sciences, New York University, New York, New York 10012, United States
- NYU-ECNU
Center for Computational Chemistry, NYU Shanghai, 3663 Zhongshan
Road North, Shanghai 200062, China
| | - Michael A. Hickner
- Department
of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Stephen J. Paddison
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
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25
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Abstract
In this comprehensive review, recent progress and developments on perfluorinated sulfonic-acid (PFSA) membranes have been summarized on many key topics. Although quite well investigated for decades, PFSA ionomers' complex behavior, along with their key role in many emerging technologies, have presented significant scientific challenges but also helped create a unique cross-disciplinary research field to overcome such challenges. Research and progress on PFSAs, especially when considered with their applications, are at the forefront of bridging electrochemistry and polymer (physics), which have also opened up development of state-of-the-art in situ characterization techniques as well as multiphysics computation models. Topics reviewed stem from correlating the various physical (e.g., mechanical) and transport properties with morphology and structure across time and length scales. In addition, topics of recent interest such as structure/transport correlations and modeling, composite PFSA membranes, degradation phenomena, and PFSA thin films are presented. Throughout, the impact of PFSA chemistry and side-chain is also discussed to present a broader perspective.
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Affiliation(s)
- Ahmet Kusoglu
- Energy Conversion Group, Energy Technologies Area, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, MS70-108B, Berkeley, California 94720, United States
| | - Adam Z Weber
- Energy Conversion Group, Energy Technologies Area, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, MS70-108B, Berkeley, California 94720, United States
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26
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Dorenbos G. Dependence of Solvent Diffusion on Hydrophobic Block Length within Amphiphilic-Hydrophobic Block Copolymer Membranes. J Phys Chem B 2016; 120:13102-13111. [PMID: 27976579 DOI: 10.1021/acs.jpcb.6b10913] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pore networks and water diffusion within model (amphiphilic-hydrophobic) diblock copolymer membranes in the presence of 16 vol % water is studied by dissipative particle dynamics in combination with Monte Carlo tracer diffusion calculations. The amphiphilic block (parent architecture (A[A3C])10) is composed of a backbone that contains 10 consecutively connected hydrophobic A beads; to each A bead, a side chain is grafted composed of three connected A beads and a pendant hydrophilic C bead. Hydrophobic blocks are constructed from x covalently bonded A beads, with x = 20, 30, or 50. Water diffusion through the pores is modeled by Monte Carlo tracer diffusion within more than 500 mapped morphologies. Long range water diffusion within the amphiphilic-hydrophobic ((A[A3C])10-Ax) diblock architectures increases with hydrophobic block length. Diffusion increases with Q = ⟨Nbond⟩|C||1 - C|-1, where C is the hydrophilic C bead fraction and ⟨Nbond⟩ the average number of bonds that A beads are separated from the nearest C bead. These trends are also anticipated for amphiphilic parent architectures (ACA3)10, (A2[C]A2)10, and (A2[AC]A)10. This is explained by the squeezing of water from the hydrophobic phase into the amphiphilic phase. Two characteristic distances are observed: The shorter distance corresponds to the interpore (or intercluster) separation within the "parent architecture-water" phase and obeys the earlier obtained linear relation between intercluster distance and ⟨Nbond⟩amphi of the amphiphilic parent architecture. The longer distance is governed by the phase separation between the amphiphilic-water phase and hydrophobic blocks.
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Affiliation(s)
- G Dorenbos
- T410-1118, 1107-2, sanno, Belle Crea 502, Susono, Japan
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27
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Lu J, Jacobson LC, Perez Sirkin YA, Molinero V. High-Resolution Coarse-Grained Model of Hydrated Anion-Exchange Membranes that Accounts for Hydrophobic and Ionic Interactions through Short-Ranged Potentials. J Chem Theory Comput 2016; 13:245-264. [PMID: 28068769 DOI: 10.1021/acs.jctc.6b00874] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Jibao Lu
- Department
of Chemistry, The University of Utah, Salt Lake City, Utah 84112-0850, United States
| | - Liam C. Jacobson
- Department
of Chemistry, The University of Utah, Salt Lake City, Utah 84112-0850, United States
| | - Yamila A. Perez Sirkin
- Departamento
de Química Inorgánica, Analítica y Química
Física, and INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires C1428EHA, Argentina
| | - Valeria Molinero
- Department
of Chemistry, The University of Utah, Salt Lake City, Utah 84112-0850, United States
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Dorenbos G. Water Diffusion Dependence on Amphiphilic Block Design in (Amphiphilic-Hydrophobic) Diblock Copolymer Membranes. J Phys Chem B 2016; 120:5634-45. [PMID: 27266679 DOI: 10.1021/acs.jpcb.6b03171] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polyelectrolyte membranes (PEMs) are applied in polyelectrolyte fuel cells (PEFC). The proton conductive pathways within PEMs are provided by nanometer-sized water containing pores. Large-scale application of PEFC requires the production of low-cost membranes with high proton conductivity and therefore good connected pore networks. Pore network formation within four alternative model diblock (hydrophobic_amphiphilic) copolymers in the presence of water is studied by dissipative particle dynamics. Each hydrophobic block contains 50 consecutively connected hydrophobic (A) fragments, and amphiphilic blocks contain 40 hydrophobic A beads and 10 hydrophilic C beads. For one amphiphilic block the C beads are distributed uniformly along the backbone. For the other architectures C beads are located at the end of the side chains attached at regular intervals along the backbone. Water diffusion through the pores is modeled by Monte Carlo tracer diffusion through mapped morphologies. Diffusion is highest for the grafted architectures and increases with increase of length of the side chains. A consistent picture emerges in which diffusion strongly increases with the value of ⟨Nbond⟩ within the amphiphilic block, where ⟨Nbond⟩ is the average number of bonds between hydrophobic A beads and the nearest C bead.
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Affiliation(s)
- Gert Dorenbos
- T410-1118, sano 1107-2, Belle Crea 502, Susono, Japan
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30
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Lee MT, Vishnyakov A, Neimark AV. Coarse-grained model of water diffusion and proton conductivity in hydrated polyelectrolyte membrane. J Chem Phys 2016; 144:014902. [DOI: 10.1063/1.4938271] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Ming-Tsung Lee
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, New Jersey 08854-8058, USA
| | - Aleksey Vishnyakov
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, New Jersey 08854-8058, USA
| | - Alexander V. Neimark
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, New Jersey 08854-8058, USA
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31
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Kulvelis Y, Ivanchev SS, Primachenko ON, Lebedev VT, Marinenko EA, Ivanova IN, Kuklin AI, Ivankov OI, Soloviov DV. Structure and property optimization of perfluorinated short side chain membranes for hydrogen fuel cells using orientational stretching. RSC Adv 2016. [DOI: 10.1039/c6ra23445c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Stretching of membranes with low molecular weight makes structure rearrangement according to neutron scattering data on D2O-filled membranes.
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Affiliation(s)
- Yu. V. Kulvelis
- Neutron Researches Department
- B.P. Konstantinov Petersburg Nuclear Physics Institute
- National Research Centre “Kurchatov Institute”
- Gatchina
- Russia
| | - S. S. Ivanchev
- St. Petersburg Department of Boreskov Institute of Catalysis
- Siberian Branch of Russian Academy of Sciences
- St. Petersburg
- Russia
| | - O. N. Primachenko
- St. Petersburg Department of Boreskov Institute of Catalysis
- Siberian Branch of Russian Academy of Sciences
- St. Petersburg
- Russia
| | - V. T. Lebedev
- Neutron Researches Department
- B.P. Konstantinov Petersburg Nuclear Physics Institute
- National Research Centre “Kurchatov Institute”
- Gatchina
- Russia
| | - E. A. Marinenko
- St. Petersburg Department of Boreskov Institute of Catalysis
- Siberian Branch of Russian Academy of Sciences
- St. Petersburg
- Russia
| | - I. N. Ivanova
- Neutron Researches Department
- B.P. Konstantinov Petersburg Nuclear Physics Institute
- National Research Centre “Kurchatov Institute”
- Gatchina
- Russia
| | - A. I. Kuklin
- Joint Institute for Nuclear Research
- Dubna
- Russia
- Moscow Institute of Physics and Technology
- Dolgoprudny
| | - O. I. Ivankov
- Joint Institute for Nuclear Research
- Dubna
- Russia
- Moscow Institute of Physics and Technology
- Dolgoprudny
| | - D. V. Soloviov
- Joint Institute for Nuclear Research
- Dubna
- Russia
- Moscow Institute of Physics and Technology
- Dolgoprudny
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32
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Dorenbos G. Modelling linear and branched amphiphilic star polymer electrolyte membranes and verification of the bond counting method. RSC Adv 2016. [DOI: 10.1039/c5ra24172c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Water diffusion through hydrated amphiphilic star polymer membranes depends strongly on hydrophilic position within the linear and Y-shaped arms.
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33
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Anisotropic radio-chemically pore-filled anion exchange membranes for solid alkaline fuel cell (SAFC). J Memb Sci 2015. [DOI: 10.1016/j.memsci.2015.07.067] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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34
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Dorenbos G. Morphology and diffusion within model membranes: Application of bond counting method to architectures with bimodal side chain length distributions. Eur Polym J 2015. [DOI: 10.1016/j.eurpolymj.2015.05.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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35
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Dorenbos G. Searching for low percolation thresholds within amphiphilic polymer membranes: The effect of side chain branching. J Chem Phys 2015; 142:224902. [DOI: 10.1063/1.4922156] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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36
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Clark JK, Habenicht BF, Paddison SJ. Ab initio molecular dynamics simulations of aqueous triflic acid confined in carbon nanotubes. Phys Chem Chem Phys 2015; 16:16465-79. [PMID: 24983213 DOI: 10.1039/c4cp01066c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Ab initio molecular dynamics simulations were performed to investigate the effects of nanoscale confinement on the structural and dynamical properties of aqueous triflic acid (CF3SO3H). Single-walled carbon nanotubes (CNTs) with diameters ranging from ∼11 to 14 Å were used as confinement vessels, and the inner surface of the CNT were either left bare or fluorinated to probe the influence of the confined environment on structural and dynamical properties of the water and triflic acidic. The systems were simulated at hydration levels of n = 1-3 H2O/CF3SO3H. Proton dissociation expectedly increased with increasing hydration. Along with the level of hydration, hydrogen bond connectivity between the triflic acid molecules, both directly and via a single water molecule, played a role on proton dissociation. Direct hydrogen bonding between the CF3SO3H molecules, most commonly found in the larger bare CNT, also promoted interactions between water molecules allowing for greater separation of the dissociated protons from the CF3SO3(-) as the hydration level was increased. However, this also resulted in a decrease in the overall proportion of dissociated protons. The confinement dimensions altered both the hydrogen bond network and the distribution of water molecules where the H2O in the fluorinated CNTs tended to form small clusters with less proton dissociation at n = 1 and 2 but the highest at n = 3. In the absence of nearby hydrogen bond accepting sites from H2O or triflic acid SO3H groups, the water molecules formed weak hydrogen bonds with the fluorine atoms. In the bare CNT systems, these involved the CF3 groups of triflic acid and were more frequently observed when direct hydrogen bonding between CF3SO3H hindered potential hydrogen bonding sites. In the fluorinated tubes, interactions with the covalently bound fluorine atoms of the CNT wall dominated which appear to stabilize the hydrogen bond network. Increasing the hydration level increased the frequency of the OH···F (CNT) hydrogen bonding which was highly pronounced in the smaller fluorinated CNT indicating an influence on the confinement dimensions on these interactions.
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Affiliation(s)
- Jeffrey K Clark
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA.
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37
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Dorenbos G. Water diffusion within hydrated model grafted polymeric membranes with bimodal side chain length distributions. SOFT MATTER 2015; 11:2794-2805. [PMID: 25703230 DOI: 10.1039/c5sm00016e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The effect of bimodal side chain length distributions on pore morphology and solvent diffusion within hydrated amphiphilic polymeric membranes is predicted. Seven polymeric architectures are constructed from hydrophobic backbones from which at regular intervals side chains branch off that are alternatingly short (composed of p hydrophobic A fragments or beads) and long (q A fragments, q > p). The side chains are end-linked with a hydrophilic C fragment. Pore morphologies at a water volume fraction of 0.16 are calculated by dissipative particle dynamics (DPD). Water diffusion through the water containing pores is calculated by tracer diffusion calculations through 140 selected snapshots and from the water bead motions. Diffusion constants decrease with difference in side chain lengths, q - p. Overall, the distance between pores also decreases with q - p. The results are explained by counting for every architecture the average number of bonds 〈N(bond)〉 between an A and the nearest C fragment. These results are in line with a database that contains more than 60 architectures. Diffusion constants tend to increase linearly with 〈N(bond)〉|C|(-1)|A|, where |C| and |A| are the C and A bead fractions within the architecture. 〈N(bond)〉 is therefore expected to be an interesting design parameter for obtaining low percolation thresholds for solvent and/or proton diffusion.
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Affiliation(s)
- G Dorenbos
- 410-1118, 1107-2 sano, Belle Crea 502, Susono-shi, Shizuoka-ken, Japan.
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38
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Berrod Q, Lyonnard S, Guillermo A, Ollivier J, Frick B, Gébel G. QENS investigation of proton confined motions in hydrated perfluorinated sulfonic membranes and self-assembled surfactants. EPJ WEB OF CONFERENCES 2015. [DOI: 10.1051/epjconf/20158302002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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39
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Kulvelis YV, Ivanchev SS, Lebedev VT, Primachenko ON, Likhomanov VS, Török G. Structure characterization of perfluorosulfonic short side chain polymer membranes. RSC Adv 2015. [DOI: 10.1039/c5ra11838g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Perfluorinated short side chain membranes synthesized by novel aqueous emulsion method demonstrate specific structure dependent on the chemical composition.
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Affiliation(s)
- Yu. V. Kulvelis
- Neutron Researches Department
- B.P. Konstantinov Petersburg Nuclear Physics Institute
- National Research Centre “Kurchatov Institute”
- Gatchina
- Russia
| | - S. S. Ivanchev
- St. Petersburg Department of Boreskov Institute of Catalysis
- Siberian Branch of Russian Academy of Sciences
- St. Petersburg
- Russia
| | - V. T. Lebedev
- Neutron Researches Department
- B.P. Konstantinov Petersburg Nuclear Physics Institute
- National Research Centre “Kurchatov Institute”
- Gatchina
- Russia
| | - O. N. Primachenko
- St. Petersburg Department of Boreskov Institute of Catalysis
- Siberian Branch of Russian Academy of Sciences
- St. Petersburg
- Russia
| | - V. S. Likhomanov
- St. Petersburg Department of Boreskov Institute of Catalysis
- Siberian Branch of Russian Academy of Sciences
- St. Petersburg
- Russia
| | - Gy. Török
- Research Institute for Solid State Physics and Optics
- Wigner Research Centre for Physics
- Hungarian Academy of Sciences
- Budapest
- Hungary
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40
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41
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Dorenbos G. Pore design within amphiphilic polymer membranes: linear versus Y-shaped side chain architectures. RSC Adv 2014. [DOI: 10.1039/c4ra00919c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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42
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Vishnyakov A, Neimark AV. Self-assembly in Nafion membranes upon hydration: water mobility and adsorption isotherms. J Phys Chem B 2014; 118:11353-64. [PMID: 25157931 DOI: 10.1021/jp504975u] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
By means of dissipative particle dynamics (DPD) and Monte Carlo (MC) simulations, we explored geometrical, transport, and sorption properties of hydrated Nafion-type polyelectrolyte membranes. Composed of a perfluorinated backbone with sulfonate side chains, Nafion self-assembles upon hydration and segregates into interpenetrating hydrophilic and hydrophobic subphases. This segregated morphology determines the transport properties of Nafion membranes that are widely used as compartment separators in fuel cells and other electrochemical devices, as well as permselective diffusion barriers in protective fabrics. We introduced a coarse-grained model of Nafion, which accounts explicitly for polymer rigidity and electrostatic interactions between anionic side chains and hydrated metal cations. In a series of DPD simulations with increasing content of water, a classical percolation transition from a system of isolated water clusters to a 3D network of hydrophilic channels was observed. The hydrophilic subphase connectivity and water diffusion were studied by constructing digitized replicas of self-assembled morphologies and performing random walk simulations. A non-monotonic dependence of the tracer diffusivity on the water content was found. This unexpected behavior was explained by the formation of large and mostly isolated water domains detected at high water content and high equivalent polymer weight. Using MC simulations, we calculated the chemical potential of water in the hydrated polymer and constructed the water sorption isotherms, which extended to the oversaturated conditions. We determined that the maximum diffusivity and the onset of formation of large water domains corresponded to the saturation conditions at 100% humidity. The oversaturated membrane morphologies generated in the canonical ensemble DPD simulations correspond to the metastable and unstable states of Nafion membrane that are not realized in the experiments.
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Affiliation(s)
- Aleksey Vishnyakov
- Department of Chemical Engineering, Rutgers, the State University of New Jersey , 98 Brett Road, Piscataway, New Jersey 08854, United States
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43
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Wang C, Paddison SJ. Mesoscale modeling of hydrated morphologies of sulfonated polysulfone ionomers. SOFT MATTER 2014; 10:819-830. [PMID: 24651930 DOI: 10.1039/c3sm52330f] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The hydrated morphologies of sulfonated poly(phenylene) sulfone (sPSO2) ionomers as a function of equivalent weight (EW), molecular weight (MW), and water content were investigated by using mesoscale dissipative particle dynamics (DPD) simulations. The morphological changes were characterized by analyzing the water distribution and plotting the radial distribution functions for the water particles. The results were compared to typical PFSA ionomers (i.e., Nafion and Aquivion) to evaluate the effects of backbone and side chain chemistry. Our results show that water is more likely to be equally distributed within the hydrophilic domains of the sPSO2 ionomers particularly at low water content, which is in contrast to strong phase separation observed in PFSA ionomers at the same level of hydration. As the degree of sulfonation is increased (i.e., decreasing the EW), well-connected water clusters develop in the sPSO2 ionomers even at low water content which are less affected by changes in the MW than observed for PFSA ionomers. The size of the water clusters is estimated to be from 1.2 to 1.5 nm (compared to ∼ 3.5 nm in Nafion) at a water content of 7H2O/SO3H, which is consistent with results determined from previous experiments. This suggests that the high proton conductivity observed in the sPSO2 ionomers is due to the well-connected hydrophilic pathways.
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Affiliation(s)
- Chen Wang
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA.
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44
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Li J, Pan M, Tang H. Understanding short-side-chain perfluorinated sulfonic acid and its application for high temperature polymer electrolyte membrane fuel cells. RSC Adv 2014. [DOI: 10.1039/c3ra43735c] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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45
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Akkermans RL, Spenley NA, Robertson SH. Monte Carlo methods in Materials Studio. MOLECULAR SIMULATION 2013. [DOI: 10.1080/08927022.2013.843775] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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46
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Kumar M, Venkatnathan A. Mechanism of proton transport in ionic-liquid-doped perfluorosulfonic acid membranes. J Phys Chem B 2013; 117:14449-56. [PMID: 24171462 DOI: 10.1021/jp408352w] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Ionic-liquid-doped perfluorosulfonic acid membranes (PFSA) are promising electrolytes for intermediate/high-temperature fuel cell applications. In the present study, we examine proton-transport pathways in a triethylammonium-triflate (TEATF) ionic liquid (IL)-doped Nafion membrane using quantum chemistry calculations. The IL-doped membrane matrix contains triflic acid (TFA), triflate anions (TFA(-)), triethylamine (TEA), and triethylammonium cations (TEAH(+)). Results show that proton abstraction from the sulfonic acid end groups in the membrane by TFA(-) facilitates TEAH(+) interaction with the side-chains. In the IL-doped PFSA membrane matrix, proton transfer from TFA to TEA and TFA to TFA(-) occurs. However, proton transfer from a tertiary amine cation (TEAH(+)) to a tertiary amine (TEA) does not occur without an interaction with an anion (TFA(-)). An anion interaction with the amine increases its basicity, and as a consequence, it takes a proton from a cation either instantly (if the cation is freely moving) or with a small activation energy barrier of 2.62 kcal/mol (if the cation is interacting with another anion). The quantum chemistry calculations predict that anions are responsible for proton-exchange between cations and neutral molecules of a tertiary amine. Results from this study can assist the experimental choice of IL to provide enhanced proton conduction in PFSA membrane environments.
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Affiliation(s)
- Milan Kumar
- Department of Chemistry, Indian Institute of Science Education and Research , Pune 411008, India
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Yildirim E, Erciyes G, Yurtsever M. Theoretical approach to the structural, electronic, and morphological properties of poly(ɛ-caprolactone) grafted polypyrroles. Macromol Res 2013. [DOI: 10.1007/s13233-013-1111-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Xiao P, Li J, Tang H, Wang Z, Pan M. Physically stable and high performance Aquivion/ePTFE composite membrane for high temperature fuel cell application. J Memb Sci 2013. [DOI: 10.1016/j.memsci.2013.04.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Reiter GF, Deb A, Sakurai Y, Itou M, Krishnan VG, Paddison SJ. Anomalous ground state of the electrons in nanoconfined water. PHYSICAL REVIEW LETTERS 2013; 111:036803. [PMID: 23909351 DOI: 10.1103/physrevlett.111.036803] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Indexed: 06/02/2023]
Abstract
Water confined on the scale of 20 Å, is known to have different transport and thermodynamic properties from that of bulk water, and the proton momentum distribution has recently been shown to have qualitatively different properties from that exhibited in bulk water. The electronic ground state of nanoconfined water must be responsible for these anomalies but has so far not been investigated. We show here for the first time, using x-ray Compton scattering and a computational model, that the ground state configuration of the valence electrons in a particular nanoconfined water system, Nafion, is so different from that of bulk water that the weakly electrostatically interacting molecule model of water is clearly inapplicable. We argue that this is a generic property of nanoconfinement. The present results demonstrate that the electrons, and hence the protons as well, of nanoconfined water are in a distinctly different quantum state from that of bulk water. Biological cell function must make use of the properties of this state and cannot be expected to be described correctly by empirical models based on the weakly interacting molecules model.
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Affiliation(s)
- G F Reiter
- Physics Department, University of Houston, Houston, Texas 77204, USA.
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Dorenbos G, Morohoshi K. Pore morphologies and diffusion within hydrated polyelectrolyte membranes: Homogeneous vs heterogeneous and random side chain attachment. J Chem Phys 2013; 138:064902. [DOI: 10.1063/1.4789805] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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