• Shivaji V Bhosale

The CoFe2O4 and NiFe2O4 nanoparticles were synthesized by gas phase condensation method using dc thermal plasma arc method at plasma parameters of 500Torr and 6kW of dc power. Due to wide applications of magnetic nanoparticles in the field of biotechnology the colloidal stability of these nanoparticles for different inorganic ions with different ionic strength was systematically studied. The X-ray diffraction pattern confirms the single phase formation with highly crystalline spinel ferrite magnetic nanoparticles. The high saturation magnetization of 49.53 emu/gm and 46.52 emu/gm was obtained for CoFe2O4 and NiFe2O4 nanoparticles respectively. The maximum positive zeta potential of 62 mv and 61 mv (pH: 3.64) and negative zeta potential of -59 mv and -55 mv (pH: 9.66) was obtained for Co Fe2O4 and NiFe2O4 nanoparticles respectively. The isolelctric point is obtained at pH 7.12 and pH 7.38 for CoFe2O4 and NiFe2O4 nanoparticles respectively. The effect of inorganic ions (NaNO3, CaCl2, Na2SO4) on the zeta potential of nanoparticles was also systematically studied. The divalent ions (CaCl2 and Na2SO4) were observed to screen the electrostatic repulsive forces between the charged particles and reduce the zeta potential of nanoparticles. Further, since the cations/anions were not specifically adsorbed on the surfaces of nanoparticles, no shift in the isoelectric point was observed. The analogous results were obtained by observing the optical absorption of these suspensions. The minimum optical absorption was observed near the isoelectric point of these nanoparticles. The increase in the ionic strength of inorganic ions and ions of CaCl2 and Na2SO4 further reduced the optical absorbance of these suspensions. All these effects were observed due to the agglomeration of nanoparticles caused by the reduction in the zeta potential.

Effect of Inorganic Ions on the Colloidal Stability of Magnetic Spinel Ferrite Nanoparticles Synthesized by dc Thermal plasma Arc Route

"Effect of Inorganic Ions on the Colloidal Stability of Magnetic Spinel Ferrite Nanoparticles Synthesized by dc Thermal plasma Arc Route", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 5, page no.1-11, May - 2019, Available :http://www.jetir.org/papers/JETIRCP06001.pdf

"Effect of Inorganic Ions on the Colloidal Stability of Magnetic Spinel Ferrite Nanoparticles Synthesized by dc Thermal plasma Arc Route", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 5, page no. pp1-11, May - 2019, Available at : http://www.jetir.org/papers/JETIRCP06001.pdf