陽子伝導用アプリケーションのための高度な酸性孔を持つ水に安定した金属有機構造体です
Jared M Taylor1, Karl W Dawson, George K H Shimizu
1Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
Journal of the American Chemical Society
|January 12, 2013
まとめ
新しい金属有機フレームワークであるPCMOF-5は,湿気条件下でも高い陽子伝導性を示しています. この材料は,安定性とイオン輸送機構の洞察力を提供し,従来のイオン導体の限界を克服します.
科学分野:
- 材料科学 材料科学とは
- 電気化学 電気化学について
- クリスタログラフィーです.
背景:
- メタル・オーガニック・フレームワーク (MOF) は,イオン導体開発の新たな経路を提供します.
- MOFの結晶性は,分子レベルのイオン輸送を理解するのに役立ちます.
- 一部のMOFは,湿気のある環境では不安定であり,その応用が制限されます.
研究 の 目的:
- 強化された陽子伝導性を持つ新しい3D金属有機フレームワーク,PCMOF-5を報告する.
- 高湿度下でのPCMOF-5の構造と伝導性の性質を調査する.
- 新しいMOF素材の安定性と水分抵抗性を評価するために.
主な方法:
- 新しい3D金属有機フレームワーク (PCMOF-5) の合成.
- 60°Cと98%の相対湿度でプロトンの伝導性を測定した.
- チャンネルと機能群の結晶学的調査を含む構造分析.
- 材料の安定性と湿度の高い環境での膨張の評価.
主要な成果:
- PCMOF-5は60°Cと98%の相対湿度で10~3S/cmを超える陽子伝導性を示しています.
- この材料は,湿度の高い環境で高い安定性を示し,膨胀に抵抗します.
- 結晶学分析により,水分子とフリーフォスフォニック酸群を含むチャネルが明らかになる.
結論:
- PCMOF-5は,特に湿度の高い環境では,陽子伝導アプリケーションにとって有望な材料です.
- フリーなリン酸基と構造水の存在は,高伝導性と安定性に寄与する.
- このMOFは,分子レベルでイオン輸送機構を研究するためのプラットフォームを提供します.
関連する概念動画
02:54Ions as Acids and Bases
Salts with Acidic Ions
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
02:51Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
01:17Ion Exchange
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or basic...
02:33Lewis Acids and Bases
In 1923, G. N. Lewis proposed a generalized definition of acid-base behavior in which acids and bases are identified by their ability to accept or to donate a pair of electrons and form a coordinate covalent bond.
A coordinate covalent bond (or dative bond) occurs when one of the atoms in the bond provides both bonding electrons. For example, a coordinate covalent bond occurs when a water molecule combines with a hydrogen ion to form a hydronium ion. A coordinate covalent bond also results when...
A coordinate covalent bond (or dative bond) occurs when one of the atoms in the bond provides both bonding electrons. For example, a coordinate covalent bond occurs when a water molecule combines with a hydrogen ion to form a hydronium ion. A coordinate covalent bond also results when...
02:30Water: A Bronsted-Lowry Acid and Base
The reaction between a Brønsted-Lowry acid and water is called acid ionization. For example, when hydrogen fluoride dissolves in water and ionizes, protons are transferred from hydrogen fluoride molecules to water molecules, yielding hydronium ions and fluoride ions: