Large electrocaloric effect from electrical field induced orientational order-disorder transition in nematic liquid crystals possessing large dielectric anisotropy

Xiao Shi Qian, S. G. Lu, Xinyu Li, Haiming Gu, L. C. Chien, Qiming Zhang

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    1 Scopus citations

    Abstract

    Large electrocaloric (EC) effects in ferroelectric polymers and in ferroelectric ceramics have attracted great attention for new refrigeration development which is more environmental friendly and more efficient and thus could be an alternative to the existing vapor-compression refrigerators which consume large energy and release large amount of green house gas. However in the past, all EC effects investigations have been focused on solid state dielectrics. It is interesting to ask whether a large EC effect can also be realized in dielectric fluids. A dielectric fluid with large EC effect could lead to new design of cooling devices with simpler structures than these based on solid state EC materials, for example, they can be utilized as both the refrigerant and heat exchange fluid. Here we present that a large EC effect can be realized in the liquid crystal (LC) 5CB near it's nematic-isotropic (N-I) phase transition. The LC 5CB possesses a large dielectric anisotropy which can induce large polarization change from the isotropic phase to the nematic phase near the N-I transition. An isothermal entropy change of more than 23 Jkg -1K-1 was observed near 39 °C that is just above the N-I transition.

    Original languageEnglish (US)
    Title of host publicationNanoscale Thermoelectric Materials
    Subtitle of host publicationThermal and Electrical Transport, and Applications to Solid-State Cooling and Power Generation
    Pages13-20
    Number of pages8
    DOIs
    Publication statusPublished - Dec 1 2013
    Event2013 MRS Spring Meeting - San Francisco, CA, United States
    Duration: Apr 1 2013Apr 5 2013

    Publication series

    NameMaterials Research Society Symposium Proceedings
    Volume1543
    ISSN (Print)0272-9172

    Other

    Other2013 MRS Spring Meeting
    CountryUnited States
    CitySan Francisco, CA
    Period4/1/134/5/13

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    All Science Journal Classification (ASJC) codes

    • Materials Science(all)
    • Condensed Matter Physics
    • Mechanics of Materials
    • Mechanical Engineering

    Cite this

    Qian, X. S., Lu, S. G., Li, X., Gu, H., Chien, L. C., & Zhang, Q. (2013). Large electrocaloric effect from electrical field induced orientational order-disorder transition in nematic liquid crystals possessing large dielectric anisotropy. In Nanoscale Thermoelectric Materials: Thermal and Electrical Transport, and Applications to Solid-State Cooling and Power Generation (pp. 13-20). (Materials Research Society Symposium Proceedings; Vol. 1543). https://doi.org/10.1557/opl.2013.605