Heat transfer and flow characteristics of Fe3O4-water nanofluids under magnetic excitation

Application of iron oxide nanoparticles in oil recovery – A critical review of the properties, formulation, recent advances and prospects

A facile low-cost scheme for highly photoactive Fe3O4-MWCNTs nanocomposite material for degradation of methylene blue

The thermal conductivity enhancement of oil blend-based ferro-nanofluids for heat transfer application is rarely reported. Herein, highly stable ferro-nanofluids were prepared by dispersing oleic acid coated Fe3O4 NPs into the blend of sunflower oil and mineral oil at varying volume ratios. The maximum thermal conductivity enhancement of ~ 91% was obtained for M10 (base fluid) oil blend-based ferro-nanofluid at 0.6 vol% of Fe3O4 NPs as compared to the pure mineral oil. The dispersed NPs into the oil blend-based ferro-nanofluid executed Brownian motion which led to the collisions between the NPs as well as with the molecules of the oil blend. The formation of a chain like network by small-sized NPs effectively led to a larger volume fraction of NPs, which caused the enhancement of the thermal conductivity of oil blend-based ferro-nanofluids. Moreover, a nano-adsorption layer of oil blend was formed on the surfaces of NPs, which served as a bridge for the heat exchange between NPs and oil blend. The experimental results were validated against a similar pre-existing thermal conductivity enhancement model. Hence, this study provides a more efficient method to prepare oil-based ferro-nanofluids with a tunable thermal conductivity for heat transfer applications.

Colloidal Fe3O4 nanoparticles-based oil blend ferro-nanofluid for heat transfer application

Fe3O4 nanoparticles decorated multi-walled carbon nanotubes based magnetic nanofluid for heat transfer application

In this work, the radio frequency magnetron sputtering technique (RF sputtering) was utilized for the deposition of Y2O3-doped zinc oxide (ZnO) thin films on a SiO2 substrate. The microstructures and optical properties of the thin films deposited utilizing various gas (Ar:O2) ratios at 400 °C were characterized. XRD investigation of thin films demonstrates that all deposited films are polycrystalline and there is a single phase hexagonal wurtzite type structure with a strong (002) orientation. An increment of O2 in the gas mixture reduces the intensity of peak (002). Y2O3-doped ZnO thin films exhibited denser morphology with refined microstructure as compared to pure ZnO films. The absorbance and transmittance of doped ZnO thin films were measured by UV-VIS-IR spectrophotometer in the wavelength range 300 nm to 800 nm. High transmittance in the visible region and high band gap of films were revealed. Photoluminescence (PL) of films was estimated at the excitation wavelength of 325 nm and it uncovered two PL peaks present in UV and visible regions (400 nm to 445 nm). The effect of Ar:O2 gas proportion on stoichiometry, structural and optical properties of the Y2O3-doped ZnO thin films was also revealed. FullText for HTML: https://doi.org/10.1209/0295-5075/129/34003

Mohammad Haider

Papers

Fe3O4 nanoparticles decorated multi-walled carbon nanotubes based magnetic nanofluid for heat transfer application

Effect of Ar:O2 gas atmosphere on optical properties of Y2O3-doped ZnO thin films by RF sputtering