Synthesis and characterization of zinc doped beryllium oxide: Ethylene glycol nanofluids

The current study used ultrasound-assisted chemical precipitation to create zinc doped beryllium oxide (BeO) nanoparticles. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the synthesized samples. The effect of sonication on the size of zinc-doped BeO nanoparticles is discussed. The presence of zinc-doped BeO nanoparticles with an average crystallite size of 17.89 nm was established by X-ray diffraction. The FTIR peaks at 434.97 cm-1 and 1,110.08 cm-1 confirm Zn and Be in them. Sonication was used to disperse the nanoparticles in ethylene glycol, resulting in a nanofluid. The nanofluids were prepared in six concentrations from 0.0005 to 0.0030 wt% and characterized by ultrasound velocity and Fourier transform infrared (FTIR) spectroscopy as well as photoluminescence. Ultrasonic studies and FTIR analysis confirmed the absence of particle-fluid interactions. The maximum intensity was at 510 nm wavelength in the photoluminescence spectra, giving the electron transition energy. Thermal conductivity and viscosity revealed an optimum concentration at 0.0025 wt% zinc-doped BeO in ethylene glycol nanofluid, for maximal heat transfer with the highest thermal conductivity of 0.265 W/mK

Rheological characteristics and thermal studies of EG based Cu:ZnO hybrid nanofluids for enhanced heat transfer efficiency

The present work describes an experimental investigation of Cu-doped ZnO–EG hybrid nanofluids for better viscous nature and thermal efficiency in cooling systems. The initial phase involves synthesizing copper (Cu) doped zinc oxide (ZnO) nanoparticles using chemical precipitation method. The structural and morphological properties of these nanoparticles are determined using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Thermo-physical measurements are conducted to analyze the viscosity and thermal conductivity of Cu-doped ZnO nanofluids based on ethylene glycol (EG) at varying particle concentrations (ranging from 0.01 wt% to 0.08 wt%) with various temperature ranges of 298 K to 328 K. The observed rheological properties showed that the viscosity of tested Cu-doped ZnO-EG nanofluids exhibited non-Newtonian shear-thinning behavior due to the alignment of nanoparticle agglomerates with increasing shear rate. Similarly, the thermal properties of the prepared Cu:ZnO-EG nanofluids are examined, demonstrating a smooth increase in thermal conductivity with changes in particle concentration and temperature. The thermal conductivity ratio of the nanofluids suggests that the newly developed hybrid nanofluids exhibit superior heat transfer characteristics

Dielectric studies of H-bonded complexes of benzamide and nicotinamide with alcohols

339-334The hydrogen-bonded complexes formed by benzamide and nicotinamide with alcohols in 1, 4-dioxan were studied at 303 K. The following alcohols were used: 2-butoxy ethanol, 2-ethyl hexanol, hexan-1-ol and isopropanol. The dipole moments of the complexes were determined using Huyskens method. The excess dipole moments of the complexes were obtained from bond angle data. The results show the domination of polarization effects and the non-feasibility of higher order complexations