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Kajita T, Tanaka H, Ohtsuka Y, Orido T, Takano A, Iwamoto H, Mufundirwa A, Imai H, Noro A. Effects of a Nanophase-Separated Structure on Mechanical Properties and Proton Conductivity of Acid-Infiltrated Block Polymer Electrolyte Membranes under Non-Humidification. ACS OMEGA 2023; 8:1121-1130. [PMID: 36643438 PMCID: PMC9835166 DOI: 10.1021/acsomega.2c06514] [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: 10/10/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Acid-infiltrated block polymer electrolyte membranes adopting a spherical or lamellar nanophase-separated structure were prepared by infiltrating sulfuric acid (H2SO4) into polystyrene-b-poly(4-vinylpyridine)-b-polystyrene (S-P-S) triblock copolymers to investigate the effects of its nanophase-separated structure on mechanical properties and proton conductivities under non-humidification. Lamellae-forming S-P-S/H2SO4 membranes with a continuous hard phase generally exhibited higher tensile strength than sphere-forming S-P-S/H2SO4 membranes with a discontinuous hard phase even if the same amount of Sa was infiltrated into each neat S-P-S film. Meanwhile, the conductivities of lamellae-forming S-P-S/H2SO4 membranes under non-humidification were comparable or superior to those of sphere-forming S-P-S/H2SO4 membranes, even though they were infiltrated by the same weight fraction of H2SO4. This result is attributed to the conductivities of S-P-S/H2SO4 membranes being greatly influenced by the acid/base stoichiometry associated with acid-base complex formation rather than the nanophase-separated structure adopted in the membranes. Namely, there are more free H2SO4 moieties that can release free protons contributing to the conductivity in lamellae-forming S-P-S/H2SO4 membranes than sphere-forming S-P-S/H2SO4, even when the same amount of H2SO4 was infiltrated into the S-P-S.
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Affiliation(s)
- Takato Kajita
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya464-8603, Japan
| | - Haruka Tanaka
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya464-8603, Japan
| | - Yumiko Ohtsuka
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya464-8603, Japan
| | - Tsuyoshi Orido
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya464-8603, Japan
| | - Atsushi Takano
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya464-8603, Japan
| | - Hiroyuki Iwamoto
- Japan
Synchrotron Radiation Research Institute (JASRI), Spring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo679-5198, Japan
| | - Albert Mufundirwa
- Japan
Synchrotron Radiation Research Institute (JASRI), Spring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo679-5198, Japan
| | - Hideto Imai
- NISSAN
ARC LTD., 1 Natsushima, Yokosuka, Kanagawa237-0061, Japan
| | - Atsushi Noro
- Department
of Molecular & Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya464-8603, Japan
- Research
Center for Net-Zero Carbon Society, Institutes of Innovation for Future
Society, Nagoya University, Furo-cho, Chikusa-ku, Nagoya464-8601, Japan
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Piñón-Balderrama CI, Leyva-Porras C, Conejo-Dávila AS, Zaragoza-Contreras EA. Sulfonated Block Copolymers: Synthesis, Chemical Modification, Self-Assembly Morphologies, and Recent Applications. Polymers (Basel) 2022; 14:polym14235081. [PMID: 36501479 PMCID: PMC9740409 DOI: 10.3390/polym14235081] [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: 09/24/2022] [Revised: 11/10/2022] [Accepted: 11/14/2022] [Indexed: 11/25/2022] Open
Abstract
Scientific research based on the self-assembly behavior of block copolymers (BCs) comprising charged-neutral segments has emerged as a novel strategy mainly looking for the optimization of efficiency in the generation and storage of electrical energy. The sulfonation reaction re- presents one of the most commonly employed methodologies by scientific investigations to reach the desired amphiphilic character, leading to enough ion concentration to modify and control the entire self-assembly behavior of the BCs. Recently, several works have studied and exploited these changes, inducing improvement on the mechanical properties, ionic conduction capabilities, colloidal solubility, interface activity, and stabilization of dispersed particles, among others. This review aims to present a description of recent works focused on obtaining amphiphilic block copolymers, specifically those that were synthesized by a living/controlled polymerization method and that have introduced the amphiphilic character by the sulfonation of one of the segments. Additionally, relevant works that have evidenced morphological and/or structural changes regarding the pristine BC as a result of the chemical modification are discussed. Finally, several emerging practical applications are analyzed to highlight the main drawbacks and challenges that should be addressed to overcome the development and understanding of these complex systems.
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