Browsing by Subject "reduced graphene oxide"

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Access status: Open Access ,
Hybrid piezo-, pyro-, and triboelectric nanogenerator based on PVDF and rGO composite fibers for a multifunctional approach to energy harvesting applications
(2025) Sukumaran, Sunija; Szewczyk, Piotr K.; Bajda, Tomasz; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki Przemysłowej
Recently, wearable nanogenerators have gained interest in energy harvesting and sensors, driven by smart electronics and Internet of Things (IoT) advancements. Here, we have developed a multifunctional nanogenerator that can convert mechanical and thermal energy into electrical energy via piezoelectric, triboelectric, and pyroelectric effects. The electrospun nanogenerator was fabricated to investigate the effect of reduced graphene oxide (rGO) on the energy generation of polyvinylidene fluoride (PVDF) fibers. The highest amount of electroactive β phase (81 %) and crystallinity (48.58 %) were obtained for 7 wt% rGO/PVDF fiber composite. Then, the 7 wt% rGO/PVDF composite was taken to prepare the piezo, tribo, and pyroelectric nanogenerator, and characterized using piezoresponse force microscopy (PFM), Kelvin probe microscopy (KPFM), and scanning thermal microscopy (SThM). Furthermore, the nanogenerator was made using the composite mat, illustrating its potential for powering small electronic devices using piezoelectric power and an enormous triboelectric power density of 3.37 ± 0.72 mWcm−2. We also demonstrate the device’s multifunctionality under thermal fluctuations. The results show the synergetic tribo and pyroelectric current of 33nA from 7 wt% rGO/PVDF. The present work indicates the significance of rGO inclusion into a PVDF matrix, resulting in enhanced multifunctional properties for energy harvesting, thereby enabling self-powering capabilities for microelectronic devices.
Access status: Open Access ,
Optimizing Piezoelectric Coefficient in PVDF Fibers: Key Strategies for Energy Harvesting and Smart Textiles
(2023) Sukumaran, Sunija; Szewczyk, Piotr K.; Knapczyk-Korczak, Joanna; Stachewicz, Urszula
Wydział Inżynierii Metali i Informatyki Przemysłowej
With the advancement in smart electronic devices and self-powered devices, the demand for piezoelectric polymers found potential research interest. Among these, electrospun polyvinylidene fluoride (PVDF) fibers have gained attention for energy harvesting due to their flexibility and higher piezoelectric coefficient. We compare various methods to enhance PVDF's piezoelectric properties, including different solvents (DMAc, DMF), conductive filler (rGO), and annealing as post-treatment. Our results indicate that PVDF/rGO fibers in DMAc solvent exhibit the highest β phase fraction and crystallinity. Moreover, for the first time, we present the piezoelectric properties of PVDF/rGO electrospun single fiber using high voltage switching spectroscopy piezoelectric force microscopy (HVSS-PFM). The highest piezoelectric coefficient (d33) was measured for PVDF/DMAc-rGO composite fibers. Notably, PVDF/rGO in DMAc solvent significantly improves the piezoelectric coefficient, leading to a remarkable fourfold increase in power density compared to pure PVDF, making it a promising material for energy harvesting applications.