Giant barocaloric effect in commercial polyurethane

Barocaloric Properties of Thermoplastic Elastomers

“…Comparable BC properties were also demonstrated in polyurethane rubber (Bocca et al, 2021)-achieving NRC ≈11 kJ kg −1 GPa −1 (Δp = 174 MPa)-and PDMS rubber (Carvalho et al, 2018)-achieving NRC ≈9 kJ kg −1 GPa −1 (Δp = 193 MPa)-for ΔT h−c = 25 °C. The BC properties of these materials were evaluated by pressuredependent differential scanning calorimetry, indirect methods based on Maxwell's relations, or quasi-adiabatic direct measurements (Li et al, 2019;Lloveras et al, 2019;Usuda et al, 2019;Bocca et al, 2021). Although impressive barocaloric entropy and temperature changes have been observed in different classes of materials, the performance is still not sufficient to compete with conventional refrigeration technologies due to challenges associated with the thermal transport, reliability and cost.…”

“…A higher ΔS T up to 250 J kg −1 K −1 and ΔT s up to 25 °C were measured for natural rubber, albeit at a higher applied pressure (Δp ≈ 500 MPa) (Miliante et al, 2020). Comparable BC properties were also demonstrated in polyurethane rubber (Bocca et al, 2021)-achieving NRC ≈11 kJ kg −1 GPa −1 (Δp = 174 MPa)-and PDMS rubber (Carvalho et al, 2018)-achieving NRC ≈9 kJ kg −1 GPa −1 (Δp = 193 MPa)-for ΔT h−c = 25 °C. The BC properties of these materials were evaluated by pressuredependent differential scanning calorimetry, indirect methods based on Maxwell's relations, or quasi-adiabatic direct measurements (Li et al, 2019;Lloveras et al, 2019;Usuda et al, 2019;Bocca et al, 2021).…”

On the colossal barocaloric effect in higher n-alkanes

“…We performed direct measurements of the adiabatic temperature change as a function of the applied pressure and initial temperature (Δ T s (Δ P , T 1 )) in eicosane (from Sigma-Aldrich, 99% purity) using a homemade system, as described by Bocca et al , 13 based on the equipment reported by Bom et al 23 The initial temperatures of the sample ranged from 273 to 353 K, with the applied pressures of 42, 86, 130, 174 and 218 MPa, relative to the atmospheric pressure. The pressure application rates were 140, 286, 433, 580 and 726 MPa s −1 , respectively.…”

“…Potential refrigerant materials for these kinds of cooling devices are called barocaloric materials. Different types of such materials have been studied recently and exhibit giant or colossal (or supergiant) BC effects, such as plastic crystals, [6][7][8] elastomeric polymers (elastomers), [9][10][11][12][13] organic-inorganic hybrid perovskites and metalorganic frameworks [14][15][16][17] and other coordination compounds. [18][19][20] Most of the BC materials studied so far present a more pronounced BC effect only around solid-solid phase transitions, while elastomers present a giant BC effect in wider temperature ranges, even in the absence of phase transitions.…”

“…[18][19][20] Most of the BC materials studied so far present a more pronounced BC effect only around solid-solid phase transitions, while elastomers present a giant BC effect in wider temperature ranges, even in the absence of phase transitions. [9][10][11][12][13] Nevertheless, solid-liquid phase transitions may signicantly increase the BC effects, and, consequently, the potential for application in BC-based refrigerators.…”