Improved piezoelectricity of PVDF-HFP/carbon black composite films

Liangke Wu, Weifeng Yuan, Ning Hu, Zhongchang Wang, Chunlin Chen, Jianhui Qiu, Ji Ying, Yuan Li

    Research output: Contribution to journalArticlepeer-review

    44 Citations (Scopus)

    Abstract

    We report a substantial improvement of piezoelectricity for poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) copolymer films by introducing carbon black (CB) into the PVDF-HFP to form PVDF-HFP/CB composite films. The optimized output voltage of the composite film at an optimal CB content of 0.5 wt% is found to be 204% of the pristine PVDF-HFP film. Its harvested electrical power density is 464% and 561% of the pristine PVDF-HFP film by using ac and dc circuits, respectively. Through Fourier transform infrared spectroscopy analysis, differential scanning calorimetry analysis, and polarized optical microscopy observations, we clarify the enhancement mechanism of piezoelectricity for the PVDF-HFP/CB composite films. We find that the added CB acts as nucleating agent during the initial formation of crystals, but imposes an insignificant effect on the -β phase transformation during stretching. We also demonstrate that the addition of optimal CB reduces crystal size yet increases the number of crystals in the composite films. This is beneficial for the formation of elongated, oriented and fibrillar crystalline morphology during stretching and consequently results in a highly efficient poling process. The addition of overdosed CB leads to the formation of undersized crystals, lowered crystallinity, and hence reduced piezoelectric performance of the PVDF-HFP/CB composite films.

    Original languageEnglish
    Article number135302
    JournalJournal of Physics D: Applied Physics
    Volume47
    Issue number13
    DOIs
    Publication statusPublished - 2014 Apr 2

    Keywords

    • PVDF-HFP composite
    • carbon black
    • energy harvesting
    • phase transformation
    • piezoelectricity

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Condensed Matter Physics
    • Acoustics and Ultrasonics
    • Surfaces, Coatings and Films

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