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In this study, an epoxy-based nanocomposite reinforced with copper oxide-graphene oxide hybrid was investigated. Initially, the hybrid powder of CuO-GO with a weight ratio of 9:1 was prepared. The hybrid filler with different weight percentages ranging from 0.1-0.5 was used to reinforce the epoxy resin. The prepared samples were analyzed using XRD, FTIR, FESEM, TEM, and tensile testing. According to the XRD results and SEM images, the hybrid powder was successfully prepared, and the mechanical testing results showed an improvement in tensile strength in the composite samples. The best composite sample in terms of tensile strength was the one containing 0.3 wt% of hybrid reinforcement, which exhibited a 71% and 161% increase in the tensile strength and elastic modulus, respectively, as compared to the neat resin sample. [ABSTRACT FROM AUTHOR]

Considering the widespread use of aluminum composites in various industries, aluminum-based nanocomposite samples reinforced with various percentages of graphene-BN hybrid powder were fabricated in this study. Initially, the graphene-BN hybrid was prepared and later subjected to wet milling together with aluminum powder. The final composite mixtures were consolidated using spark plasma sintering (SPS) method. Using this method, aluminum-based composite specimens containing 1 wt.% graphene-0 wt.% BN (AGB1), 0.95 wt.% graphene-0.05 wt.% BN (AGB2), 0.90 wt.% graphene-0.1 wt.% BN (AGB3), and 0.85 wt.% graphene-0.15 wt.% BN (AGB4) were prepared and compared with regard to their difference in mechanical properties. Hardness values of 48.1, 51.1, 56.2, 54.1, and 43.6 Hv were obtained for AGB0, AGB1, AGB2, AGB3, and AGB4, respectively. Additionally, tensile strengths of these specimens were 67.2, 102.1, 129.5, 123.7, and 114.7 MPa, respectively. Based upon the hardness and tensile test data, it was concluded that the AGB2 specimen had the highest tensile strength (93% higher than AGB0 and 27% higher than AGB1) and also higher hardness values (17% higher than AGB0 and 10% higher than AGB1). [ABSTRACT FROM AUTHOR]

Nanocrystalline Li(Ni1/3Co1/3Mn1/3)O2 (NCM) was successfully synthesized through a solution combustion route to use as the cathode material in a Li-ion battery. The powder prepared by combustion was calcined at different temperatures of 750, 850 and 950 °C for 5–15 h. To evaluate the impact of the calcination time and temperature, the crystal growth kinetics of the obtained NCM material was investigated and the governing mechanism for the crystal growth was determined. The optimum material was discussed from both crystallographic and electrochemical standpoints. [ABSTRACT FROM AUTHOR]

Abstract: A mechanically induced self‐sustaining reaction (MSR) was used to synthesize hafnium diboride nanoparticles. Along this route, magnesium was selected as a robust reducing agent for co‐reduction in boron and hafnium oxides in a combustive manner. Combustion occurred after a short milling period of 12 minutes. The hafnium diboride nanoparticles had a polygonal faceted morphology and were 50‐250 nm in diameter. The assessment of the processing mechanism revealed that the initial combustive reduction in B2O3 to elemental B by Mg was the major step for progressing the overall reaction. After that, HfO2 can be reduced to elemental Hf, followed by the synthesis of HfB2 phase. [ABSTRACT FROM AUTHOR]

• GO–Fe 3 O 4 hybrid was prepared by an electrostatic self-assembly method. • The optical fiber was tapered by stretching during heating. • The tapered part of the optical fiber was covered by the hybrid coating and a magnetic field sensor was fabricated. • The length and diameter of the taper on the sensitivity of the sensor were studied. In this research, a magnetic field sensor based on the tapered optical fiber was fabricated. The tapered area of the optical fiber was coated by the GO–Fe 3 O 4 hybrid prepared through the electrostatic self-assembly. High sensitivity of 99–324 pW/mT was obtained for the taper lengths of 6.8–11 mm and taper diameters of 3.3–12.8 μm using a laser with a wavelength of 1550 nm (2 mW) and the magnetic flux density of 0–60 mT. It was found that the output power increased linearly as the magnetic field increased. Moreover, the sensor sensitivity increased linearly by increasing the taper length and decreasing the taper diameter due to an increase in the evanescent field penetration. [ABSTRACT FROM AUTHOR]

A ZrSiO4/B2O3/Mg/C system was used to synthesize a ZrB2-based composite through a high-energy ball milling process. As a result of the milling process, a mechanically induced self-sustaining reaction ( MSR) was achieved in this system. A composite powder of ZrB2-SiC-ZrC was prepared in situ by a magnesiothermic reduction with an ignition time of approximately 6 min. The mechanism for the formation of the product was investigated by studying the relevant subreactions, the stoichiometric amount of B2O3, and thermal analysis. [ABSTRACT FROM AUTHOR]

This study presents the synthesis of TiO 2 -graphene nanocomposites with varying mass ratios of graphene (2.5, 5, 10, 20 wt. %) using a facile and cost-effective hydrothermal approach. By integrating TiO 2 nanoparticles with graphene, a nanomaterial characterized by a two-dimensional structure, unique electrical conductivity and high specific surface area, the resulting hybrid material shows promise for application in supercapacitors. The nanocomposite specimens were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman microscopy, field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). Additionally, supercapacitive properties were investigated using a three-electrode setup by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) tests. Notably, the TiO 2 -20 wt. % rGO nanocomposite exhibited the highest specific capacitance of 624 F/g at 2 A/g, showcasing superior electrochemical performance. This specimen indicated a high rate capability and cyclic stability (93 % retention after 2000 cycles). Its remarkable energy density and power density of this sample designate it as a strong contender for practical supercapacitor applications., (© 2024 The Authors. ChemistryOpen published by Wiley-VCH GmbH.)

In this study, fabrication of a composite containing the ordinary Portland cement (OPC) and magnetite (Fe 3 O 4 ) micro/nanoparticles is reported. In the first stage, the cement paste samples with a fixed 0.2 wt.% Fe 3 O 4 additive in four different particle sizes (20-40 nm, 80-100 nm, 250-300 nm, and 1-2 µm) were prepared to check the effect of magnetite size. Magnetite was found to play an effective role in reinforcing cement matrix. The results showed that the cement paste reinforced by magnetite nanoparticles of 20-40 nm size range had the highest compressive, flexural, and tensile strengths compared to those of the other samples reinforced by larger particles. In the second stage, various amounts of the Fe 3 O 4 nanoparticles of 20-40 nm size range were added to the cement to evaluate the influence of magnetite amount and find the optimized reinforcement amount. It was revealed that adding 0.25 wt.% Fe 3 O 4 nanoparticles of 20-40 nm size range, as the optimal specimen, increased the compressive strength, flexural strength and tensile splitting strength by 23-32, 17-25, and 15-19%, respectively, and decreased the electrical resistance by 19-31%.