Yazar "Okbaz, Abdulkerim" seçeneğine göre listele

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    Enhanced performance of triboelectric nanogenerator based on polyamide-silver antimony sulfide nanofibers for energy harvesting
    (Elsevier Ltd., 2021) Yar, Adem Yazdan; Kınas, Zeynep; Karabiber, Abdulkerim; Özen, Abdurrahman; Okbaz, Abdulkerim; Özel, Faruk
    Triboelectric nanogenerators (TENGs) are new renewable energy harvesting devices that convert small-scale mechanical movements into electrical energy. Nowadays, the dielectric materials with high tribopotential are being investigated significantly to improve the energy conversion efficiency of TENGs. Nanofibers are widely used as dielectric materials in TENGs due to their high surface area and flexibility. In this study, polyacrylonitrile nanofibers and AgSbS2 doped Nylon 6.6 nanofibers were tested as dielectric layers in spring assisted TENGs. Decorating Nylon 6.6 with AgSbS2 both enhanced the output voltage and markedly advanced the power density of the TENGs, and thus improved triboelectric performance of the TENGs. According to the results, tribopotential of Nylon 6.6 was enhanced as AgSbS2 additive amount increased. Compared to PAN/Nylon 6.6 nanofibers based TENG, PAN/10 wt% AgSbS2@Nylon 6.6 nanofibers based TENG exhibited 2.95 and 1.68 fold enhancement in power density and output voltage, respectively. The peak power density of PAN/10 wt% AgSbS2@Nylon 6.6 nanofibers based TENG reached 6.81 W/m2 under a load resistance of 10 MΩ. From the perspective of the choices of materials and design, the results demonstrate that grafting AgSbS2 nanocrystal materials into Nylon 6.6 nanofibers is an effective way to make better the triboelectric performance of nanofibers mat based TENG. Therefore, the study not only shows a high triboelectric performance of nanofibers based TENG, but also shed on light new glance into the material selection, fabrication, and design for contact-separation mode TENGs.
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    High-performance triboelectric nanogenerator based on carbon nanomaterials functionalized polyacrylonitrile nanofibers
    (Elsevier Ltd., 2022) Kınas, Zeynep; Karabiber, Abdulkerim; Yar, Adem Yazdan; Özen, Abdurrahman; Ersöz, Mustafa; Özel, Faruk; Okbaz, Abdulkerim
    Triboelectric nanogenerators (TENGs) are one of the most promising energy sources for self-powered electronic devices in the near future. Improving the dielectrics with high tribo-potential is a primary requirement to increase the output performance of TENGs. In this study, spring supported TENGs consisting of polyvinylpyrrolidone/ethyl-cellulose (PVP/EC) nanofibers and various carbon-doped polyacrylonitrile (PAN) nanofibers as positive and negative dielectric layers, respectively, were fabricated. According to the experimental results, reduced graphene oxide (rGO) and carbon nanotube (CNT) which were grafted to PAN matrix, both increased surface charge density and enhanced the output voltage of the TENGs. On the other hand, carbon black (CB) reduced the tribo-potential of PAN as a negative dielectric layer. As the best result, a 40 × 40 mm2 TENG constructed of PVP/EC and 3 wt% CNT doped PAN nanofibers demonstrates high triboelectric characteristics with a charge capacity of 260 nC (under 0.022 μF capacitive load), a maximum peak output voltage of 960 V (under a 70 MΩ load resistance), and a maximum peak power density of 14.6 W/m2 (under a 14.6 MΩ load resistance). In other words, the addition of 3 wt% CNT to PAN increased the charge amount by 136%, and the maximum peak power density by 125%. This work presents an effective way to take advantage of the coupling effect of carbon additive and nanofiber structure to significantly enhance the output performance of TENGs.
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    High-performance triboelectric nanogenerator with optimized Al or Ti-embedded silicone tribomaterial
    (Elsevier Ltd., 2021) Okbaz, Abdulkerim; Karabiber, Abdulkerim; Yar, Adem Yazdan; Kınas, Zeynep; Sarılmaz, Adem; Özel, Faruk
    In this study, we have enhanced the electricity generation capacity of a silicone and glass fiber-based vertical contact separation mode triboelectric nanogenerator (TENG) by optimizing the thickness of the silicone material and by tuning the triboelectrification characteristics embedding Al or Ti conductive materials. Considering electrical outputs, the optimum thickness of the silicone triboelectric material layer decorated with 2.5 wt% Al or 2.5 wt% Ti is found to be 0.85 mm. The silicone and glass fiber-based TENG delivers the highest performance with 2.5 wt% Al or 5 wt% Ti embedding. The peak power density of 2.5 wt% Al or 5 wt% Ti-embedded silicone glass fiber TENGs are 22.6 W/m2 and 21.3 W/m2, respectively. Embedding 2.5 wt% Al or 5 wt% Ti enhances output power density by 2.19 folds and 2.06 folds, respectively compared to the pure silicone tribonegative layer. We have demonstrated that using conductive fillers significantly increases the TENGs' powers and charging capacities
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    Transition Metal Dichalcogenides as Effective Dopants in Nanofiber-Based Triboelectric Nanogenerators
    (Wiley, 2024) Karabiber, Abdulkerim; Dirik, Ömer; Okbaz, Abdulkerim; Yar, Adem; Özen, Abdurrahman; Özel, Faruk
    Triboelectric nanogenerators (TENGs) are advanced energy harvesters that convert mechanical energy in diverse environments into electrical energy via static electrification and electrostatic induction. However, their performance needs to be improved to expand their area of use and become more practical. In this study, we introduced molybdenum disulfide (MoS2) and tungsten disulfide (WS2) as separate additives into polyacrylonitrile (PAN) to produce composite nanofibers via electrospinning, aiming to increase the electrical output of the TENGs. This method increased contact area by narrowing the nanofiber diameters, which is a key factor in enhancing the triboelectric effect. The incorporation of MoS2 or WS2, characterized by high specific surface area, interface polarization, quantum confinement effects, and strong electron acceptance and trapping capabilities, led to a significant increase in the dielectric constant and overall electrical performance of the TENGs. Experimental evaluations, connecting the TENGs to circuits with various resistive loads, determined optimal performance at a load resistance of 4.7 M Omega. In particular, the 5 wt% WS2@PAN & polyvinylbutral (PVB) and 5 wt% MoS2@PAN & PVB TENGs exhibited a remarkable peak power output of 40.5 mW, corresponding to a power density of 25.3 W/m2 and provided open circuit voltage of 1,026 V. The integration of 5 wt% MoS2 or 5 wt% WS2 led to more than a twofold increase in electrical power density compared to pristine PAN. These outcomes demonstrate the significant impact of transition metal dichalcogenides in enhancing the energy conversion efficiency of contact-separation mode TENGs, thereby contributing to the advancement of energy harvesting technology.