Atomic structure and dynamics of barocaloric frameworks for solid-state cooling

用于固态冷却的压热框架的原子结构和动力学

• 批准号: EP/S03577X/1
• 负责人: Anthony Phillips
• 金额: $ 48.23万
• 依托单位: Queen Mary University of London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FS03577X%2F1
• 关键词: Atomic; structure; dynamics; barocaloric; frameworks

Refrigeration technologies across a wide range of temperatures are at the core of modern society, from making skyscrapers inhabitable to cooling the high-power magnets used in MRI scans. Yet the refrigeration cycle most commonly used, based on vapour compression, is environmentally unsustainable, relying on gases that contribute both to ozone depletion and global warming. As a result, there is an immediate and widely-recognised global need for new cooling technologies.One of the most promising such technologies is based on materials known as barocalorics. As pressure is applied to these materials, the degree of order with which the component atoms are arranged changes, which raises or lowers the temperature of the material. By cycling back and forth between high- and low-pressure states, a cooling cycle can be created that pumps heat out of a refrigerated area. However, only a few such materials are known. A major bottleneck delaying this technology from widespread use is simply identifying and optimising suitable barocaloric materials.In this project, we will investigate a series of newly-discovered barocalorics that belong to the broad family of metal-organic frameworks. These materials are promising barocalorics for several reasons: they are highly susceptible to small changes in pressure; they often undergo order-disorder phase transitions of the sort described above; and in theory it is possible to adjust the components of these materials in order to tune their properties, for instance to increase the barocaloric effect. However, there are far too many possible components to test them all by trial and error. Instead, what is needed is a systematic understanding of exactly what atomic-level features produce our target materials' remarkable barocaloric properties.Our research programme aims to achieve exactly this understanding. We will perform neutron (alongside X-ray and Raman) scattering experiments on our target materials: these are ideally suited to map not just the positions but also the motion of the atoms. To complement our experimental data, we will also perform computer simulations of these materials. Our experimental data will confirm that our models match reality well, while our simulated data will provide information that could not be extracted from experiment alone.Combining our experimental with our simulated data, we will elucidate the way in which the barocaloric effect emerges from these materials' structure and dynamics. Based on these results, we will predict ways to achieve an even greater barocaloric effect in metal-organic frameworks. Our results will help to direct future exploration, providing a road map to help develop technologically exploitable materials as quickly as possible.

从使摩天大楼适合居住到冷却核磁共振扫描中使用的高功率磁铁，各种温度范围内的制冷技术都是现代社会的核心。然而，最常用的基于蒸汽压缩的制冷循环在环境上是不可持续的，依赖于导致臭氧消耗和全球变暖的气体。因此，全球对新的冷却技术的需求迫在眉睫，并得到了广泛的认可。其中最有前途的一项技术是基于被称为大气压的材料。当压力施加到这些材料上时，组成原子排列的有序度会发生变化，从而提高或降低材料的温度。通过在高压和低压状态之间来回循环，可以创建一个冷却循环，将热量从冷藏区泵出。然而，只有少数这样的材料是已知的。阻碍这项技术广泛应用的一个主要瓶颈是简单地识别和优化合适的压热材料。在这个项目中，我们将研究一系列新发现的压热材料，它们属于金属-有机骨架的广泛家族。这些材料很有希望成为正压材料，原因有几个：它们对压力的微小变化非常敏感；它们经常经历上述类型的有序-无序相变；从理论上讲，可以调整这些材料的成分以调整它们的性能，例如增加压力效应。然而，可能的组件太多了，无法通过反复试验来测试它们。相反，我们需要的是系统地了解到底是什么原子水平的特征产生了我们目标材料的非凡的高压热性质。我们的研究计划旨在实现这一理解。我们将在我们的目标材料上进行中子(以及X射线和拉曼)散射实验：这些实验不仅非常适合绘制原子的位置，而且还适合绘制原子的运动。为了补充我们的实验数据，我们还将对这些材料进行计算机模拟。我们的实验数据将证实我们的模型很好地符合实际，而我们的模拟数据将提供仅从实验中无法提取的信息。结合我们的实验和我们的模拟数据，我们将阐明从这些材料的结构和动力学中产生压热效应的方式。基于这些结果，我们将预测在金属-有机骨架中实现更大的高压热效应的方法。我们的成果将有助于指导未来的探索，为尽快开发技术上可开发的材料提供路线图。

项目成果

The magnetocaloric effect of the lanthanide fluorides: Using polarized neutron scattering to probe a magnetocaloric suitable for hydrogen liquefaction

• DOI: 10.1063/5.0139726
• 发表时间: 2023-04
• 期刊: APL Materials
• 影响因子: 6.1
• 作者: R. Dixey;A. Wildes;Patrick W. Doheny;G. Stenning;P. Saines

Pressure dependence of rotational dynamics in barocaloric ammonium sulfate

• DOI: 10.1103/physrevb.106.064302
• 发表时间: 2022-01
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Bernet E. Meijer;Guanqun Cai;F. Demmel;H. Walker;A. E. Phillips

Origin of the Large Entropy Change in the Molecular Caloric and Ferroelectric Ammonium Sulfate

分子热量和铁电硫酸铵大熵变的起源

• DOI: 10.1002/adfm.202207717
• 发表时间: 2022
• 期刊: Advanced Functional Materials
• 影响因子: 19
• 作者: Yuan S

Dynamics in the ordered and disordered phases of barocaloric adamantane

高压金刚烷有序相和无序相的动力学

• DOI: 10.1039/d2cp05412d
• 发表时间: 2023
• 期刊: Physical Chemistry Chemical Physics
• 影响因子: 3.3
• 作者: Meijer B

Pressure dependence of atomic dynamics in barocaloric ammonium sulfate: II. Vibrations

高压硫酸铵中原子动力学的压力依赖性：II。

• DOI: 10.48550/arxiv.2202.08606
• 发表时间: 2022
• 作者: Yuan S