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Gran efecto electrocalórico en polímeros ferroeléctricos cerca de la temperatura ambiente
Bret Neese1, Baojin Chu, Sheng-Guo Lu
1Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA.
Science (New York, N.Y.)
|August 9, 2008
Resumen
Los investigadores exploraron el efecto electrocalórico (ECE) en polímeros polares para la refrigeración. Encontraron ECE significativo en P ((VDF-TrFE) y polímeros relacionados, lo que demuestra el potencial para tecnologías avanzadas de refrigeración en estado sólido.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- La termodinámica es la termodinámica.
- La ciencia de los polímeros es la ciencia de los polímeros.
Sus antecedentes:
- La aplicación de campos eléctricos a los polímeros polares puede alterar el orden dipolar, lo que potencialmente permite aplicaciones de enfriamiento a través de cambios de entropía.
- El efecto electrocalórico (ECE) es un fenómeno prometedor para el enfriamiento en estado sólido, impulsado por cambios en la entropía de un material bajo un campo eléctrico.
Objetivo del estudio:
- Investigar el efecto electrocalórico en los polímeros ferroeléctricos, específicamente P ((VDF-TrFE) y los copolímeros relacionados.
- Para cuantificar el cambio de entropía isotérmica y el cambio de temperatura adiabática alcanzables con estos materiales para aplicaciones de refrigeración.
Principales métodos:
- Utilizó la relación de Maxwell que conecta el coeficiente piroeléctrico y el efecto electrocalórico.
- Se midió experimentalmente la ECE en el copolímero ferroeléctrico de poli (vénilideno fluoruro-trifluoroetileno) [P (VDF-TrFE) ].
- Investigó un polímero ferroeléctrico relajante, P ((VDF-TrFE-clorofluoroetileno), para ECE cerca de la temperatura ambiente.
Principales resultados:
- Se logró un gran efecto electrocalórico en P(VDF-TrFE) por encima de 70°C (por encima de la transición ferroeléctrica-paraeléctrica).
- Se observó un cambio de entropía isotérmica superior a 55 J/kg·K y un cambio de temperatura adiabática superior a 12°C.
- Se ha demostrado una ECE comparable cerca de la temperatura ambiente en P ((VDF-TrFE-clorofluoroetileno).
Conclusiones:
- Los polímeros ferroeléctricos como el P ((VDF-TrFE) exhiben efectos electrocalóricos significativos adecuados para el enfriamiento.
- Los polímeros ferroeléctricos Relaxor ofrecen potencial para aplicaciones de refrigeración en estado sólido a temperatura ambiente.
- El estudio destaca la viabilidad de los materiales electrocalóricos basados en polímeros para una gestión térmica eficiente.
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