In the last decade,numerous physical modification methods have been introduced to enhance triboelectric nanogenerator(TENG)performance although they generally require complex and multiple fabrication processes.This st...In the last decade,numerous physical modification methods have been introduced to enhance triboelectric nanogenerator(TENG)performance although they generally require complex and multiple fabrication processes.This study proposes a facile fabrication process for Poly(vinylidene fluoride)(PVDF)nanofiber(NF)mats incorporating additive and nonadditive physical modifications.Patterned PVDF NF mats are prepared by electrospinning using a metal mesh as the NF collector.As a negative triboelectric material,the TENG with the patterned PVDF NF mat exhibits superior performance owing to the engineered morphology of the contact layer.PVDF is crucial in TENGs owing to its superior ferroelectric properties and surface charge density when combined with specific electroceramics.Hence,the synergy of the physical modification methods is achieved by incorporating BaTiO3(BTO)nanoparticles(NPs)into the PVDF.By functionalizing BTO NPs with polydopamine,the TENG performance is further improved owing to the enhanced dispersion of NPs and improved crystallinity of the PVDF chains.Utilizing large NPs produces a nanopatterning effect on the NF surface,thereby resulting in the hierarchical structure of the NF mats.The source of the voltage signals from the TENG is analyzed using fast Fourier transform.展开更多
The size effect of the polydopamine(PDA)-coated BaTiO_(3)(BTO)(BTO@PDA)nanoparticles(NPs)on the interfacial compatibility between BTO NPs and the polymer matrix and the resultant piezoelectric performance of the compo...The size effect of the polydopamine(PDA)-coated BaTiO_(3)(BTO)(BTO@PDA)nanoparticles(NPs)on the interfacial compatibility between BTO NPs and the polymer matrix and the resultant piezoelectric performance of the composite films remain elusive.In this study,BTO and BTO@PDA NPs of various sizes were incorporated into a P(VDF-TrFE)matrix to prepare two series of P(VDF-TrFE)/BTO and P(VDF-TrFE)/BTO@PDA composites.Subsequently,the effects of the NP size on the dielectric,ferroelectric,and piezoelectric properties of the composite films were comprehensively studied.As the size of the BTO@PDA NPs increased,residual hole defects were clearly observed in the cross section of the composite film.The deteriorated interfacial compatibility due to the large size of the BTO@PDA NPs was also confirmed by the increased dielectric permittivity of the composite film,which was induced by the intensified interfacial polarisation.The P(VDF-TrFE)/BTO@PDA composite with NPs of the smallest size(100 nm)exhibited superior piezoelectric performance owing to the excellent interfacial compatibility between the fillers and the matrix.The piezoelectric performance was significantly enhanced by the reduced leakage current during electrical poling and reduced trap charges.Finally,the pulse waveform originating from the radial artery was precisely measured using the optimised P(VDF-TrFE)/BTO@PDA composite film.展开更多
基金supported by the Research Program funded by the SeoulTech(Seoul National University of Science and Technology).
文摘In the last decade,numerous physical modification methods have been introduced to enhance triboelectric nanogenerator(TENG)performance although they generally require complex and multiple fabrication processes.This study proposes a facile fabrication process for Poly(vinylidene fluoride)(PVDF)nanofiber(NF)mats incorporating additive and nonadditive physical modifications.Patterned PVDF NF mats are prepared by electrospinning using a metal mesh as the NF collector.As a negative triboelectric material,the TENG with the patterned PVDF NF mat exhibits superior performance owing to the engineered morphology of the contact layer.PVDF is crucial in TENGs owing to its superior ferroelectric properties and surface charge density when combined with specific electroceramics.Hence,the synergy of the physical modification methods is achieved by incorporating BaTiO3(BTO)nanoparticles(NPs)into the PVDF.By functionalizing BTO NPs with polydopamine,the TENG performance is further improved owing to the enhanced dispersion of NPs and improved crystallinity of the PVDF chains.Utilizing large NPs produces a nanopatterning effect on the NF surface,thereby resulting in the hierarchical structure of the NF mats.The source of the voltage signals from the TENG is analyzed using fast Fourier transform.
基金This work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2022R1F1A107172011).
文摘The size effect of the polydopamine(PDA)-coated BaTiO_(3)(BTO)(BTO@PDA)nanoparticles(NPs)on the interfacial compatibility between BTO NPs and the polymer matrix and the resultant piezoelectric performance of the composite films remain elusive.In this study,BTO and BTO@PDA NPs of various sizes were incorporated into a P(VDF-TrFE)matrix to prepare two series of P(VDF-TrFE)/BTO and P(VDF-TrFE)/BTO@PDA composites.Subsequently,the effects of the NP size on the dielectric,ferroelectric,and piezoelectric properties of the composite films were comprehensively studied.As the size of the BTO@PDA NPs increased,residual hole defects were clearly observed in the cross section of the composite film.The deteriorated interfacial compatibility due to the large size of the BTO@PDA NPs was also confirmed by the increased dielectric permittivity of the composite film,which was induced by the intensified interfacial polarisation.The P(VDF-TrFE)/BTO@PDA composite with NPs of the smallest size(100 nm)exhibited superior piezoelectric performance owing to the excellent interfacial compatibility between the fillers and the matrix.The piezoelectric performance was significantly enhanced by the reduced leakage current during electrical poling and reduced trap charges.Finally,the pulse waveform originating from the radial artery was precisely measured using the optimised P(VDF-TrFE)/BTO@PDA composite film.
