Synthesis, surface modification and characterisation of biocompatible magnetic iron oxide nanoparticles for biomedical applications.

Superparamagnetic iron oxide nanoparticles (MNPs) with appropriate surface chemistry exhibit many interesting properties that can be exploited in a variety of biomedical applications such as magnetic resonance imaging contrast enhancement, tissue repair, hyperthermia, drug delivery and in cell separation. These applications required that the MNPs such as iron oxide Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) having high magnetization values and particle size smaller than 100 nm. This paper reports the experimental detail for preparation of monodisperse oleic acid (OA)-coated Fe3O4 MNPs by chemical co-precipitation method to determine the optimum pH, initial temperature and stirring speed in order to obtain the MNPs with small particle size and size distribution that is needed for biomedical applications. The obtained nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence spectrometry (EDXRF), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and vibrating sample magnetometer (VSM). The results show that the particle size as well as the magnetization of the MNPs was very much dependent on pH, initial temperature of Fe²âº and Fe³âº solutions and steering speed. The monodisperse Fe3O4 MNPs coated with oleic acid with size of 7.8 ± 1.9 nm were successfully prepared at optimum pH 11, initial temperature of 45°C and at stirring rate of 800 rpm. FTIR and XRD data reveal that the oleic acid molecules were adsorbed on the magnetic nanoparticles by chemisorption. Analyses of TEM show the oleic acid provided the Fe3O4 particles with better dispersibility. The synthesized Fe3O4 nanoparticles exhibited superparamagnetic behavior and the saturation magnetization of the Fe3O4 nanoparticles increased with the particle size.

Copper extraction by fatty hydroxamic acids derivatives synthesized based on palm kernel oil.

Fatty hydroxamic acids derivatives based on palm kernel oil which are phenyl fatty hydroxamic acids (PFHAs), methyl fatty hydroxamic acids (MFHAs), isopropyl fatty hydroxamic acids (IPFHAs) and benzyl fatty hydroxamic acids (BFHAs) were applied as chelating agent for copper liquid-liquid extraction. The extraction of copper from aqueous solution by MFHAs, PFHAs, BFHAs or IPFHAs were carried out in hexane as an organic phase through the formation of copper methyl fatty hydroxamate (Cu-MFHs), copper phenyl fatty hydroxamate (Cu-PFHs), copper benzyl fatty hydroxamate (Cu-BFHs) and copper isopropyl fatty hydroxamate (Cu-IPFHs). The results showed that the fatty hydroxamic acid derivatives could extract copper at pH 6.2 effectively with high percentage of extraction (the percentages of copper extraction by MFHAs, PFHAs, IPFHs and BFHAs were found to be 99.3, 87.5, 82.3 and 90.2%, respectively). The extracted copper could be quantitatively stripped back into sulphuric acid (3M) aqueous solution. The obtained results showed that the copper recovery percentages from Cu-MFHs, Cu-PFHs, Cu-BFHs and Cu-IPFHs are 99.1, 99.4, 99.6 and 99.9 respectively. The copper extraction was not affected by the presence of a large amount of Mg (II), Ni (II), Al (III), Mn (II) and Co (II) ions in the aqueous solution.

Benzyl and methyl fatty hydroxamic acids based on palm kernel oil as chelating agent for liquid-liquid iron(III) extraction.

Liquid-liquid iron(III) extraction was investigated using benzyl fatty hydroxamic acids (BFHAs) and methyl fatty hydroxamic acids (MFHAs) as chelating agents through the formation of iron(III) methyl fatty hydroxamate (Fe-MFHs) or iron(III) benzyl fatty hydroxamate (Fe-BFHs) in the organic phase. The results obtained under optimized conditions, showed that the chelating agents in hexane extract iron(III) at pH 1.9 were realized effectively with a high percentage of extraction (97.2% and 98.1% for MFHAs and BFHAs, respectively). The presence of a large amount of Mg(II), Ni(II), Al(III), Mn(II) and Co(II) ions did affect the iron(III) extraction. Finally stripping studies for recovering iron(III) from organic phase (Fe-MFHs or Fe-BFHs dissolved in hexane) were carried out at various concentrations of HCl, HNO(3) and H(2)SO(4). The results showed that the desired acid for recovery of iron(III) was 5 M HCl and quantitative recovery of iron(III) was achieved from Fe(III)-MFHs and Fe(III)-BFHs solutions in hexane containing 5 mg/L of Fe(III).