Ultrasonic cavitation induced water in vegetable oil emulsion droplets – A simple and easy technique to synthesize manganese zinc ferrite nanocrystals with improved magnetization

Abstract

In the present investigation, synthesis of manganese zinc ferrite (Mn(0.5)Zn(0.5)Fe(2)O(4)) nanoparticles with narrow size distribution have been prepared using ultrasound assisted emulsion (consisting of rapeseed oil as an oil phase and aqueous solution of Mn(2+), Zn(2+) and Fe(2+) acetates) and evaporation processes. The as-prepared ferrite was nanocrystalline. In order to remove the small amount of oil present on the surface of the ferrite, it was subjected to heat treatment at 300 °C for 3h. Both the as-prepared and heat treated ferrites have been characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), TGA/DTA, transmission electron microscopy (TEM) and energy dispersion X-ray spectroscopy (EDS) techniques. As-prepared ferrite is of 20 nm, whereas the heat treated ferrite shows the size of 33 nm. In addition, magnetic properties of the as-prepared as well as the heat treated ferrites have also been carried out and the results of which show that the spontaneous magnetization (σ(s)) of the heat treated sample (24.1 emu/g) is significantly higher than that of the as-synthesized sample (1.81 emu/g). The key features of this method are avoiding (a) the cumbersome conditions that exist in the conventional methods; (b) usage of necessary additive components (stabilizers or surfactants, precipitants) and (c) calcination requirements. In addition, rapeseed oil as an oil phase has been used for the first time, replacing the toxic and troublesome organic nonpolar solvents. As a whole, this simple straightforward sonochemical approach results in more phase pure system with improved magnetization.

Sonochemical synthesis of Gd3+ doped CoFe2O4 spinel ferrite nanoparticles and its physical properties

“…al. [36] reported a facile route of an ultrasound-assisted synthesis of nanocrystalline manganese zinc ferrite with narrow size distribution. Their simple straightforward sonochemical approach resulted in a better pure phase system of nanoferrite with improved magnetic properties.…”

Charge of water droplets in non-polar oils

“…The electrical generator, which is connected to the mains, converts the input electricity into an alternating electrical signal (ranging from 20 kHz to tens of MHz), which drives the transducer [64][65][66]. A transducer contains piezoelectric crystals, which, upon receiving the electrical signal, start to oscillate, causing the horn or probe to longitudinally expand and contract.…”

Effect of type and loading of surfactant on ultrasound-assisted synthesis of CaZn2(PO4)2 nanoparticles by chemical precipitation

“…and due to strong alkalinity of calcium hydroxide, OH -ions gets released in its aqueous suspension [20][21][22][23][24]. These OH -ions can destroy the structure of ZnO in the presence of ultrasonic irradiation due to the amphoteric property of zinc oxide, leading to the formation of calcium zincate media [18].…”