Acid resistant functionalised magnetic nanoparticles for radionuclide and heavy metal adsorption.

Coating superparamagnetic iron oxide NPs with SiO has been established in order to confer stability in acidic media. Acid stability tests were carried out between pH 1 and pH 7 to determine the effectiveness of the SiO passivating layer to protect the magnetic FeO core. Transmission Electron Microscopy (TEM) and zeta potential measurements have shown that uncoated FeO NPs exhibit rapid agglomeration and dissolution when exposed to acidic media, moving from a zeta potential of - 26 mV to a zeta potential of + 3 mV.