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In this study, basalt and/or beech wood fibers were treated with vinyltrimethoxysilane or compatibilized by maleic anhydride‐ grafted polypropylene (MAPP) to produce hybrid polylactic acid (PLA) biocomposites. Twin‐screw extruder was used to produce biocomposites, following by a hot press to form samples. Physical and mechanical properties of composites that were produced from both treated and untreated fibers were compared. Chemical, morphological, and thermal analysis of biocomposites were analyzed with TGA, FTIR and SEM, respectively. The results showed that silane treated basalt/wood fiber reinforced PLA (PBWS) and silane treated basalt reinforced PLA (PBS) have significantly better flexural strength than neat PLA. Besides, basalt reinforced bio‐composites except PBW3 and PBWM variations have significantly superior impact strength than neat PLA. Utilization of compatibilizers also reduced thickness swelling and water uptake features of biocomposites. All the above experimental data showed that the utilization of silane compatibilizer has better impact on properties than MAPP for such wood/basalt hybrid composite. Highlights: Hybrid biocomposites with wood and basalt fibers by using coupling agents were prepared for the first time.Hybridization of organic and inorganic fibers gave promising results.Silane and maleic anhydride compatibilization improves physical properties.Vinyltrimethoxy silane grafted basalt fiber improves flexural strength significantly.Silanization of wood or basalt fibers enhances significantly the impact strength. [ABSTRACT FROM AUTHOR]

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Copyright of SPORMETRE: The Journal of Physical Education & Sport Sciences / Beden Eğitimi ve Spor Bilimleri Dergisi is the property of SPORMETRE: The Journal of Physical Education & Sport Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Today, there is a great demand for the development of portable, lightweight, flexible, and stable devices that produce and store energy to provide the power that wearable electronics and smart textile materials need. For this purpose, in recent years, researchers have focused on the development of nanofiber-based nanogenerators that have high surface areas thanks to their nanofibrous structures. Therefore, this study presents the development of piezoelectric nanogenerators made of poly(vinylidene fluoride) (PVDF) nanofibers and graphene-based flexible electrodes via electrospray deposition (ESD) technique using electrospinning devices. First, graphene oxide (GO) was electrosprayed onto the PVDF-nanofiber surface, then, the coated GO layer was reduced by chemical treatment to obtain reduced-GO (rGO) and to increase the electrical conductivity. With the ESD technique, it has been observed that graphene oxide nanosheets successfully wrapped on the nanofibers without agglomerating, and this effect was further enhanced by the reduction process. The effect of different thicknesses of graphene electrodes on the efficiency of nanogenerators was investigated. As a result, a maximum peak-to-peak voltage of 1.00 V was produced by a rGO-sprayed nanofiber-based nanogenerator, while 0.688 V was obtained with pure PVDF nanofibers. Also, "voltage-per-gram" analysis showed that the output voltage was directly related to the electrode morphology and thickness. [ABSTRACT FROM AUTHOR]

Recently, piezoelectric nanogenerators have received great interest as they can convert waste mechanical and radiative energy to electricity and can be used in self‐energy generating systems and sensor technologies. In this study, electrospun poly(vinylidene fluoride) (PVDF) nanofiber‐based piezoelectric nanogenerators with reduced graphene oxide (rGO), polyaniline (PANI), and PANI‐functionalized rGO (rGOPANI) have been developed. Two different types of nanofiber mats were produced: First, rGO‐ and rGOPANI‐doped PVDF nanofiber mats and second, rGO, PANI and rGOPANI‐spray‐coated PVDF nanofiber mats that have worked as nanogenerators' electrodes. Then, characterizations of samples were performed in terms of piezoelectricity, Fourier transform infrared (FTIR) spectrophotometric, X‐ray diffractions (XRD), and scanning electron microscopy analyses. FTIR and XRD results confirmed that piezoelectric β‐crystalline phase of PVDF occurred after the electrospinning process. Besides, maximum output voltages were obtained as 7.84 and 10.60 V for rGO‐doped PVDF and rGOPANI‐coated PVDF nanofiber mats, respectively. As a result, the doped nanofibers were found to be more successful due to the higher device accuracy in sensor technologies compared with spray‐coated samples. However, spray‐coating method proved to be more suitable technique for the production of nanogenerators on an industrial scale in terms of fast and large‐scale applicability. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48517. [ABSTRACT FROM AUTHOR]