Giant Barocaloric Effects in Natural Rubber: A Relevant Step toward Solid-State Cooling

Area of Science:

• Materials Science
• Thermodynamics
• Solid-State Physics

Background:

• Solid-state cooling using caloric effects is an emerging alternative to conventional refrigeration.
• Barocaloric materials, particularly shape-memory alloys, have recently shown significant effects, but research on polymers is limited.
• Polymers possess high caloric potential, yet their barocaloric properties remain largely unexplored.

Purpose of the Study:

• To investigate giant barocaloric effects in natural rubber, an environmentally friendly and low-cost elastomer.
• To evaluate the potential of natural rubber for practical solid-state cooling applications.
• To understand the relationship between the barocaloric effect and the glass transition in natural rubber.

Main Methods:

• Experimental investigation of barocaloric properties in natural rubber.
• Measurement of entropy and temperature changes under pressure cycling.
• Analysis of the dependence of the barocaloric effect on the material's thermal transitions.

Main Results:

• Demonstration of giant barocaloric effects in natural rubber, exceeding previously reported values for barocaloric materials.
• Observation of substantial entropy and temperature changes, indicating high cooling potential.
• Significant normalized temperature change and refrigerant capacity confirmed for natural rubber.

Conclusions:

• Natural rubber exhibits giant barocaloric effects, making it a highly promising material for solid-state cooling.
• The findings suggest the feasibility of developing commercial refrigeration devices utilizing elastomer polymers.
• The barocaloric effect's dependence on the glass transition in natural rubber provides insights for material design.