Characterization and Chemical Stability of Hydrophilic and Hydrophobic Magnetic Nanoparticles

Abstract

Magnetic nanoparticles can improve the efficiency of phase separation time in multi-stage operations when a magnetic field is present. As such operations involve contact with aqueous and/or organic solutions, hydrophilic magnetic nanoparticles synthesized through the co-precipitation method were functionalized with oleic acid to attain hydrophobic magnetic nanoparticles. Both nanoparticles were characterized morphologically, chemically and magnetically. The results revealed that the particles (size ≈ 10 nm) consisted of an iron oxide mixture of magnetite and maghemite. The functionalization with oleic acid was effective in converting them into hydrophobic nanoparticles. Both particles were ferro/ferrimagnetic and the presence of oleic acid did not interfere significantly in the saturation magnetization value. The chemical stability of both nanoparticles were also evaluated, as an attempt of simulating broad industrial conditions to which the nanoparticles may be subjected; the hydrophilic nanoparticles were resistant at pH ≥ 4, while the hydrophobic nanoparticles were stable at pH ≥ 3.

A nano-magnetic electrochemical sensor for the determination of mood disorder related substances

“…The ngerprint peaks of Fe 3 O 4 were observed in the following 2q sequence: (220) at 30.1 ; (311) at 35.5 ; (400) at 43.2 ; (422) at 53.5 ; (511) at 57.2 ; and (440) at 62.8 . These results are consistent with those reported in the literature 26,27 for Fe 3 O 4 . Fig.…”

Fe3O4@C core-shell nanoparticles as adsorbent of ionic zinc: evaluating of the adsorptive capacity

“…The combination of both properties in a nanoscale structure allows predicting applications of magnetite core-shell nanoparticles in effluent treatment systems. This method provides a quick and efficient separation of the nanoparticles dispersed in an effluent [18][19][20][21] , since after adsorption the core-shell can be removed in a continuous process by the use of magnetic fields outside of pipelines, which are projected to attend this function.…”

Evaluation of Fe-Mg Binary Oxide for As (III) Adsorption—Synthesis, Characterization and Kinetic Modelling

“…A vibration band observed at 1428 cm −1 can be due to the CO 3 2− stretching frequency due to the adsorption of gaseous -phase CO 2 [ 39 , 40 ]. It is important to note that the peak observed at 598, which can be assigned to Fe–O–Fe stretching modes, has shifted to a higher frequency from 570 when mixed oxides of Fe-Mg are formed [ 39 , 41 , 42 , 43 , 44 ]. The bands that appeared at low frequencies of 860 and 441 cm −1 correspond to stretching vibrations of Mg–O–Mg bonding also shows a shift towards a higher frequency range, which corresponds with previously reported work [ 38 , 45 , 46 , 47 ].…”