Characterization and study on triboelectric behavior of ZrB2 Nanoparticles synthesized via electrospinning method

نوع: Type: Thesis

مقطع: Segment: masters

عنوان: Title: Characterization and study on triboelectric behavior of ZrB2 Nanoparticles synthesized via electrospinning method

ارائه دهنده: Provider: Khadijeh Hemati Azandaryani

اساتید راهنما: Supervisors: Dr. Hamid Esfahani

اساتید مشاور: Advisory Professors:

اساتید ممتحن یا داور: Examining professors or referees: Dr. Mohsen Sheykhi_ Dr. Mino Karbasi

زمان و تاریخ ارائه: Time and date of presentation: 2026

مکان ارائه: Place of presentation: سالن کنفرانس

چکیده: Abstract: Abstract: One of the most attractive and widely applied areas in the field of electrical materials is nanotechnology and its use in the fabrication of triboelectric materials, capableing of converting mechanical energy into electrical energy. The incorporation of zirconium diboride (ZrB2) nanoparticles carrying a negative surface charge into polyvinylidene fluoride (PVDF) polymer matrix fibers can enhance triboelectric performance. In this study, carbon fibers containing Zr and B precursors were produced by electrospinning followed by post-calcination at 1000 °C, yielding relatively spherical particles with average diameters of 89 ± 21 nm and 103 ± 49 nm for the ZB1 fibers (1:1 ratio of B2O3 to ZrO2) and the fibers with fourfold B content (ZB4), respectively. Phase analysis of the particles revealed that, in addition to ZrB2, other boride phases such as ZrB and ZrB12 formed alongside the oxide phases B2O3 and the principal phase ZrO2, with their contents varying according to the boron content of the system. The zeta potential of the ZB1 and ZB4 nanoparticles was −51.2 mV and −46.9 mV, respectively. To investigate the effect of these particles on the microstructure, and the electrical and triboelectric behavior of PVDF fibers, composite fibers containing 1 wt% of the particles were produced by electrospinning. The average diameters of the PVDF-ZB1 and PVDF-ZB4 fibers were 253 ± 93 nm and 479 ± 79 nm, respectively. The presence of ZB1 and ZB4 nanoparticles increased the electroactive β-phase fraction of the PVDF fibers to 0.773 and 0.793, respectively. The dielectric constant and surface resistance of the fibers increased upon incorporation of the ZB1 and ZB4 nanoparticles. The results showed that the PVDF-ZB1 fibers exhibited the highest piezoelectric coefficient (d33) among all the fibers (1.28 pC/N). The triboelectric behavior of the PVDF fibers modified with ZB1 and ZB4 nanoparticles was markedly improved in both contact-separation and lateral modes. The results indicated that the PVDF-ZB4 fibers performed best in the contact-separation mode with a power density of 35.78 W/m², while the PVDF-ZB1 fibers performed best in the lateral mode with a power density of 67.89 W/m². Finally, the performance of the PVDF fibers modified with ZB1 and ZB4 nanoparticles was evaluated for acoustic energy harvesting (AEH) over an input sound frequency range of 250 to 2000 Hz. The results showed that the highest harvesting power density was obtained for the PVDF-ZB4 fibers, reaching 1.35 mW/g at 2000 Hz. The findings of this study demonstrate that ZrO₂-ZrB₂ nanoparticles can be employed to enhance the performance of polymer systems for energy generation and harvesting applications.