适应无有机-无机哈洛比斯穆酸大压电效应
Esther Y H Hung1, Benjamin M Gallant2,3, Robert Harniman4
1Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom.
Journal of the American Chemical Society
|November 25, 2025
概括
研究人员开发了一种新的混合压电材料,[CH3) 3NCH2I] 3Bi2I9,它显示出显著增强的压电反应. 这一突破为低成本,低毒性自动供电电子设备和能源采集设备提供了新的途径.
科学领域:
- 材料科学
- 固态化学
- 纳米技术
背景情况:
- 分子压电为灵活,低毒性自动供电电子产品提供了一个有前途的途径.
- 由于结构设计和相位过渡控制方面的挑战,目前的分子压电器具有有限的压电响应.
研究的目的:
- 开发一种具有增强性能的新型混合压电材料.
- 研究分子结构,相位转换和压电性质之间的关系.
主要方法:
- 使用低对称的无机框架和准球形有机阴离子合成混合物材料[CH3) 3NCH2I]3Bi2I9.
- 可变温度单晶X射线衍射分析结构变化.
- 固态核磁共振光谱用于研究相位过渡.
主要成果:
- 材料[(CH3) 3NCH2I] 3Bi2I9表现出同时发生的顺序-失序和位移性对称性破坏的相位过渡.
- 这种转变是由有机和无机成分之间的素结合驱动的.
- 获得了高压电系数 (d33 = 161.5 pm/V),比以前的化物质提高了四倍.
结论:
- 设计的混合材料在压电性能方面取得了重大进步.
- 这项工作为设计高性能分子压电器提供了一种新策略.
- 这种材料在机械能量采集和执行中具有低成本,低毒性应用的潜力.
相关概念视频
Common Ion Effect
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Châtelier’s principle. Consider the dissolution of silver iodide:
Henderson-Hasselbalch Equation
The ionization-constant expression for a solution of a weak acid can be written as:
Calculating pH Changes in a Buffer Solution
A buffer can prevent a sudden drop or increase in the pH of a solution after the addition of a strong acid or base up to its buffering capacity; however, such addition of a strong acid or base does result in the slight pH change of the solution. The small pH change can be calculated by determining the resulting change in the concentration of buffer components, i.e., a weak acid and its conjugate base or vice versa. The concentrations obtained using these stoichiometric calculations can be used...
Buffer Effectiveness
Buffer solutions do not have an unlimited capacity to keep the pH relatively constant . Instead, the ability of a buffer solution to resist changes in pH relies on the presence of appreciable amounts of its conjugate weak acid-base pair. When enough strong acid or base is added to substantially lower the concentration of either member of the buffer pair, the buffering action within the solution is compromised.
The buffer capacity is the amount of acid or base that can be added to a given volume...
The buffer capacity is the amount of acid or base that can be added to a given volume...
Titration of a Weak Base with a Strong Acid
The titration curve of a weak base like ammonia with a strong acid like hydrochloric acid is the mirror image of the titration curve of a weak acid with a strong base.
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...
Debye–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,...


