一种12-tungstophosphoric酸的液态衍生物,具有异常高的导电性
Athanasios B Bourlinos1, Kannan Raman, Rafael Herrera
1Department of Materials Science and Engineering, School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA.
Journal of the American Chemical Society
|November 26, 2004
概括
研究人员从固体异聚酸中制造出一种新型的液态盐,实现了高温质子导电性. 这种功能化的材料与其固体形式相比,具有显著增强的质子导电性.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 固态化学 固态化学
背景情况:
- 固体异聚酸如H3PW12O40是众所周知的质子导体.
- 实现高质子导电性,特别是在干燥条件下,仍然是固体电解质的挑战.
- 表面功能化提供了一条修改材料性能的途径.
研究的目的:
- 开发一种基于聚氧甲酸盐的新型液盐,具有增强的质子导电性.
- 在高温和干燥条件下研究功能化材料的质子导电性.
- 为了比较液态盐与其固体前体的导电性.
主要方法:
- 在H3PW12O40的表面功能化中,通过部分质子交换使用含有PEG的大型四级氨酸.
- 一种基于聚氧甲酸盐的液盐的合成.
- 在干燥条件下测量高温质子导电性 (在140°C时约为10^-3 S cm^-1).
- 分析使用沃尔登图来评估离子行为.
主要成果:
- 一种基于聚氧甲酸盐的新型液盐成功合成.
- 液态盐在干燥条件下在140°C时显示出高温质子导电率约为10^-3 S cm^-1.
- 质子导电性比固体模拟物高出四个数量级.
- 该材料表现出超离子行为,正如沃尔登图表所指出的那样.
结论:
- 异聚酸的表面功能化可以产生具有优越质子导电性的液态盐.
- 开发的液态盐是高温质子导电应用的有希望的候选者,特别是在干燥的环境中.
- 该研究强调了基于聚氧甲酸盐的液体盐作为先进电解质的潜力.
相关概念视频
03:38Polyprotic Acids
Acids are classified by the number of protons per molecule that they can give up in a reaction. Acids such as HCl, HNO3, and HCN that contain one ionizable hydrogen atom in each molecule are called monoprotic acids. Their reactions with water are:
02:08Titration of a Polyprotic Acid
A polyprotic acid contains more than one ionizable hydrogen and undergoes a stepwise ionization process. If the acid dissociation constants of the ionizable protons differ sufficiently from each other, then the titration curve for such polyprotic acid generates a distinct equivalence point for each of its ionizable hydrogens. Therefore, titration of a diprotic acid results in the formation of two equivalence points, whereas the titration of a triprotic acid results in the formation of three...
01:29Electrical Transport
The electrical transport property of a material is defined by its resistance and conductivity. Resistance is the measure of a material's ability to resist the flow of electric current, while conductivity gauges its ability to allow the current to pass through, depending on the geometry of the measurement cell, such as electrode spacing and area. Conductivity is measured in Siemens (S). There are different types of conductance, including specific conductance, equivalent conductance, and molar...
01:22Conductometric Titrations: Strong Acid-Weak Base and Weak Acid-Strong Base Titrations
When a weak acid such as acetic acid is titrated against a strong base like sodium hydroxide, the initial conductance is relatively low due to the weak dissociation of acetic acid. However, as sodium hydroxide is added to the solution, it reacts with the acetic acid to produce highly ionized sodium acetate, which causes an increase in conductance. Once all the acetic acid has been neutralized, any additional sodium hydroxide introduces fast-moving hydroxyl ions, leading to a sharper increase in...
01:28Debye–Huckel–Onsager Conductance Equation
The Debye-Hückel-Onsager equation is a cornerstone of physical chemistry, providing a method to determine the molar conductance (Λm) and molar conductance at infinite dilution (Λ°m) for uni-univalent electrolytes.Uni-univalent electrolytes are electrolytes that dissociate in solution to produce one cation with a +1 charge and one anion with a –1 charge per formula unit.This equation addresses two crucial phenomena: the asymmetry effect and the electrophoretic effect. According to this equation,...
01:23Titration of Polyprotic Acids with a Strong Base
Titration of a polyprotic acid, which contains multiple ionizable protons, involves distinct dissociation steps, each with its own dissociation constant (Ka). Each successive Ka is weaker than the previous one. In the titration of a polyprotic acid like sulfurous acid with a strong base such as sodium hydroxide, the base first neutralizes the initial ionizable proton, forming an intermediate species (e.g., hydrogen sulfite ions). This step's titration curve resembles that of a weak monoprotic...