Exploring new materials for caloric cooling
type: CreativeWork
description: Caloric materials produce nominally reversible thermal changes when subjected to an applied driving field. These materials are widely considered a potential replacement to the environmentally harmful refrigerant fluids that are currently used in vapour compression systems. Barocaloric materials that are driven by changes in hydrostatic pressure are comparatively the most promising type of caloric material, as they display the largest thermal changes, are practically more cost-effective, and can withstand large cyclic changes in hydrostatic pressure without breaking down or decreasing performance. This work reports on a selection of superionic conductors and metal-organic frameworks that were chosen based on their promising thermodynamic properties for barocaloric studies. Furthermore, novel ways of driving caloric effects are explored by exploiting latent heat from first-order phase transitions in a smart polymer driven by stimuli unexplored in the field of calorics thus far. Despite displaying large thermally driven entropy changes (|∆S₀|) near superionic transitions, the superionic conductors studied here showed a tendency to exist in many stoichiometric compositions and metastable states, which hindered their barocaloric performance. Complex calorimetric data from synthesised Ag-Cu-S ternary materials were understood to be an effect of variation in the pressure-dependence of the transition in different stoichiometries of the individual Ag-Cu-S ternary phases present. Furthermore, both conventional and inverse barocaloric effects were produced within each individual sample, which resulted from two different phases of the ternary system. Similar phase-related complexity was demonstrated for Ag₂Se and Cu₂Se. The metal-organic frameworks studied display improved barocaloric performance. Large reversible isothermal entropy changes |∆S(it)| ∼ 14 J K¯¹ kg¯¹ and adiabatic temperature changes |∆T(ad)| ∼ 5 K due to changes in applied pressure |∆p| ∼ 1 kbar were evaluated i…
abstract: Caloric materials produce nominally reversible thermal changes when subjected to an applied driving field. These materials are widely considered a potential replacement to the environmentally harmful refrigerant fluids that are currently used in vapour compression systems. Barocaloric materials that are driven by changes in hydrostatic pressure are comparatively the most promising type of caloric material, as they display the largest thermal changes, are practically more cost-effective, and can withstand large cyclic changes in hydrostatic pressure without breaking down or decreasing performance. This work reports on a selection of superionic conductors and metal-organic frameworks that were chosen based on their promising thermodynamic properties for barocaloric studies. Furthermore, novel ways of driving caloric effects are explored by exploiting latent heat from first-order phase transitions in a smart polymer driven by stimuli unexplored in the field of calorics thus far. Despite displaying large thermally driven entropy changes (|∆S₀|) near superionic transitions, the superionic conductors studied here showed a tendency to exist in many stoichiometric compositions and metastable states, which hindered their barocaloric performance. Complex calorimetric data from synthesised Ag-Cu-S ternary materials were understood to be an effect of variation in the pressure-dependence of the transition in different stoichiometries of the individual Ag-Cu-S ternary phases present. Furthermore, both conventional and inverse barocaloric effects were produced within each individual sample, which resulted from two different phases of the ternary system. Similar phase-related complexity was demonstrated for Ag₂Se and Cu₂Se. The metal-organic frameworks studied display improved barocaloric performance. Large reversible isothermal entropy changes |∆S(it)| ∼ 14 J K¯¹ kg¯¹ and adiabatic temperature changes |∆T(ad)| ∼ 5 K due to changes in applied pressure |∆p| ∼ 1 kbar were evaluated i…
author: Dilshad, Melony
language: eng
keywords: barocaloric, barosorptiocaloric, first-order transitions, metal-organic frameworks, pH-caloric, smart polymer, solvocaloric, superionic conductors
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2022-07-14
date modified: 2026-07-22T22:24:28Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.95442