Simulation and Synthesis of Cobalt (Co) Nanoparticles by Gamma Radiation Technique.

Cobalt nanoparticles were synthesized using the gamma radiolytic technique, and the particle size was found to be reduced from 12±1 to 7±1 nm by increasing the dose from 10 to 60 kGy. The UV-visible absorption spectra were measured and exhibited a steady absorption maxima at 517 nm in the UV region, which blue-shifted toward a lower wavelength with a decrease in particle size. By taking the conduction electrons of an isolated particle that are not entirely free but are instead bound to their respective quantum levels, the optical absorption of the cobalt nanoparticles can be calculated and simulated via intra-band quantum excitation for particle sizes comparable to the measured ones.

Effect of Al thickness on the structural and ethanol vapor sensing performance of ZnO porous nanostructures prepared by microwave-assisted hydrothermal method.

Highly porous ZnO nanoflakes were successfully prepared using a microwave-assisted hydrothermal method. The presence of aluminum changes the environment of the preparation reaction, which controlled the crystallographic orientation. The unique morphology and properties of ZnO nanoflakes may be due to the effect of microwave irradiation and the ambient condition.

Physical and optical studies of Gd O S:Eu nanophosphors by microwave irradiation and γ-irradiation methods.

Gd O S:Eu nanophosphors have been successfully synthesized using microwave irradiation and γ-irradiation methods with polyvinyl pyrrolidone as a stabilizer. The physical and luminescence spectra were compared. The morphologies of both Gd O S:Eu nanophosphors were in the hexagonal phase and mainly consisted of spherical nanostructures with diameters of ~90 nm and ~50 nm for both microwave irradiation and γ-irradiation methods.

Photothermal Effect of Modulating Laser Irradiation on the Thermal Diffusivity of AlO Nanofluids.

Modulated continuous wave (CW) lasers cause photothermal effect that leads to rapid optical absorption and generation of thermal waves around the irradiated nanostructures. In this work, we examined the effect of modulated CW laser irradiation on the particle fragmentation process to enhance the thermal diffusivity of nanofluids. A facile and cost-effective diode laser was applied to reduce the agglomerated size of AlO nanoparticles in deionized water.

Thermal Wavelength Measurement of Nanofluid in an Optical-Fiber Thermal Wave Cavity Technique to Determine the Thermal Diffusivity.

The application of optical-fiber thermal wave cavity (OF-TWC) technique was investigated to measure the thermal diffusivity of Ag nanofluids. The thermal diffusivity was obtained by measuring the thermal wavelength of sample in a cavity scan mode. The spherical Ag nanoparticles samples were prepared at various sizes using the microwave method.

One-step formation of TiO hollow spheres via a facile microwave-assisted process for photocatalytic activity.

Mesoporous TiO hollow spherical nanostructures with high surface areas were successfully prepared using a microwave method. The prepared hollow spheres had a size range between 200 and 500 nm. The spheres consisted of numerous smaller TiO nanoparticles with an average diameter of 8 nm.

Sonochemical synthesis and characterization of CoO nanocrystals in the presence of the ionic liquid [EMIM][BF].

For the first time, a sonochemical process has been used to synthesis cobalt oxide CoO nanoflowers and nanorods morphology in the presence of the ionic liquid 1-Ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF] as reaction media and morphology template. Different sonication time periods and different molar ratios of the ionic liquid (IL) were used to investigate their effects on the structural, optical, chemical and magnetic properties of the produced CoO nanoparticles. During synthesis process brown powder contains cobalt hydroxide Co(OH) and cobalt oxyhydroxide (Cobalt hydroxide oxide) CoO(OH) was formed, after calcination in air for 4h at 400°C a black powder of CoO nanoparticles was produced.

Environmental Synthesis of Few Layers Graphene Sheets Using Ultrasonic Exfoliation with Enhanced Electrical and Thermal Properties.

In this paper, we report how few layers graphene that can be produced in large quantity with low defect ratio from exfoliation of graphite by using a high intensity probe sonication in water containing liquid hand soap and PVP. It was founded that the graphene powder obtained by this simple exfoliation method after the heat treatment had an excellent exfoliation into a single or layered graphene sheets. The UV-visible spectroscopy, FESEM, TEM, X-ray powder diffraction and Raman spectroscopy was used to analyse the graphene product.

Fabrication, characterization, and thermal property evaluation of silver nanofluids.

Silver nanoparticles were successfully prepared in two different solvents using a microwave heating technique, with various irradiation times. The silver nanoparticles were dispersed in polar liquids (distilled water and ethylene glycol) without any other reducing agent, in the presence of the stabilizer polyvinylpyrrolidone (PVP). The optical properties, thermal properties, and morphology of the synthesized silver particles were characterized using ultraviolet-visible spectroscopy, photopyroelectric technique, and transmission electron microscopy.

Modified microwave method for the synthesis of visible light-responsive TiO2/MWCNTs nanocatalysts.

Recently, TiO2/multi-walled carbon nanotube (MWCNT) hybrid nanocatalysts have been a subject of high interest due to their excellent structures, large surface areas and peculiar optical properties, which enhance their photocatalytic performance. In this work, a modified microwave technique was used to rapidly synthesise a TiO2/MWCNT nanocatalyst with a large surface area. X-ray powder diffraction, field-emission scanning electron microscopy, transmission electron microscopy and Brunauer-Emmett-Teller measurements were used to characterise the structure, morphology and the surface area of the sample.

Self-assembled potential bio nanocarriers for drug delivery.

Self-assembled nanocarriers attract increasing attention due to their wide application in various practical fields; among them, one of the most focused fields is drug delivery. Appropriate selection of surfactant is the basis for preparing a successful nanocarrier. Until now, from phospholipid to synthetic surfactants, many surfactants have been used to explore a suitable drug delivery vehicle for the complex in-vivo environment.

Ternary phase behaviour and vesicle formation of a sodium N-lauroylsarcosinate hydrate/1-decanol/water system.

The phase behaviour of a system composed of amino acid-based surfactant (sodium N-lauroylsarcosinate hydrate), 1-decanol and deionised water was investigated for vesicle formation. Changing the molar ratio of the amphiphiles, two important aggregate structures were observed in the aqueous corner of the phase diagram. Two different sizes of microemulsions were found at two amphiphile-water boundaries.

The effect of the head group on branched-alkyl chain surfactants in glycolipid/n-octane/water ternary system.

Two novel glycolipids have been synthesized and their phase behaviour studied. They have been characterized using FT-IR, FAB and 13C NMR and 1H NMR to ensure the purity of novel glycolipids. The two glycolipids are distinguished based on the head group of glycolipids (monosaccharide/glucose and disaccharide/maltose).

Assessment of radiofrequency/microwave radiation emitted by the antennas of rooftop-mounted mobile phone base stations.

Radiofrequency (RF) and microwave (MW) radiation exposures from the antennas of rooftop-mounted mobile telephone base stations have become a serious issue in recent years due to the rapidly evolving technologies in wireless telecommunication systems. In Malaysia, thousands of mobile telephone base stations have been erected all over the country, most of which are mounted on the rooftops. In view of public concerns, measurements of the RF/MW levels emitted by the base stations were carried out in this study.