• Journal of Ceramic Processing Research
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• v.21 no.4
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• pp.479-487
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• 2020

Ceramic ZnS nanocomposites were prepared by mechanical processing and one-step heat sintering with powder mixtures of fly ash, waste glass, and ZnS (template-free hydrothermal method manufacturing). Chemical durability and morphological characteristics of heat-treated samples at 800 ℃ with/without acid treatment were evaluated. The photocatalytic activities were estimated with methyl orange (MO), methylene blue (MB), acetaldehyde (ATA), and 2,4-dichlorophenoxyacetic acid (2,4-D) as photodegradation targets. Crystallization behaviors of the prepared ceramic ZnS nanocomposites were investigated using X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectrometry (EDS). In addition, compressive and bending strength as mechanical properties were evaluated. Ceramic ZnS nanocomposites were found to showed improvement in optimal photocatalytic reaction and physical properties regardless of acid treatment when the amount of ZnS nanoparticles was increased from 7.0 to 25.0 wt%. Degrees of photocatalytic decomposition of MO, ATA, 2,4-D, and MB by acid treated ceramic ZnS nanocomposites containing 25 wt% ZnS were about 0.185, 0.121, 0.216, 0.236, respectively, after UV irradiation for 180 min.

• Journal of Ceramic Processing Research
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• v.20 no.4
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• pp.411-417
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• 2019

Graphene doped zinc oxide nanoparticles (G-ZnO) were prepared using modified hummer's technique together with the ultrasonic method and characterized by field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), fourier-transform infrared spectroscopy (FTIR) and high-resolution transmission electron microscopy (HRTEM). Different samples of epoxy resin nanocomposites reinforced with G-ZnO nanoparticles were prepared and were marked as F1 (without adding nanoparticles), F2 (1% w/w G-ZnO), and F3 (2% w/w G-ZnO) in combination of ≈ 56:18:18:8w/w% with epoxy resin/hardener, ammonium polyphosphate, boric acid, and Chitosan. The peak heat release rate (PHRR) of the epoxy nanocomposites was observed to decrease dramatically with the increasing G-ZnO nanoparticles. However, the LOI values increased significantly with the increase in wt % of G-ZnO nanoparticles. From the UL-94V data, it was confirmed that the F2 and F3 samples passed the flame test and were rated as V-0. The results obtained in the present work clearly revealed that the synthesized samples can be used as efficient materials in fire-retardant coating technology.

• Journal of the Korean Society of Clothing and Textiles
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• v.47 no.3
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• pp.577-592
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• 2023

In this study, nanofiber-based textile sensors were developed for motion detection and monitoring. Poly(vinylidene fluoride) (PVDF) nanofibers containing zinc oxide (ZnO) nanoparticles and silver nanowires (AgNW) were fabricated using electrospinning. PVDF was chosen as a piezoelectric polymer, zinc oxide as a piezoelectric ceramic, and AgNW as a metal to improve electric conductivity. The PVDF/ZnO/AgNW nanocomposite fibers were used to develop a textile sensor, which was then incorporated into an elbow band to develop a wearable smart band. Changes in the output voltage and peak-to-peak voltage (V_p-p) generated by the joint's flexion and extension were investigated using a dummy elbow. The β-phase crystallinity of pure PVDF nanofibers was 58% when analyzed using Fourier transform infrared spectroscopy; however, the β-phase crystallinity increased to 70% in PVDF nanofibers containing ZnO and to 78% in PVDF nanocomposite fibers containing both ZnO and AgNW. The textile sensor's output voltage values varied with joint-bending angle; upon increasing the joint angle from 45° to 90° to 150°, the V_p-p value increased from 0.321 V_p-p to 0.542 V_p-p to 0.660 V_p-p respectively. This suggests that the textile sensor can be used to detect and monitor body movements.