Contact potential induced enhancement of magnetization in polyaniline coated nanomagnetic iron oxides by plasma polymerization

Abstract

The present work derives motivation from the so called surface/interfacial magnetism in core shell structures and commercial samples of Fe3O4 and γ Fe2O3 with sizes ranging from 20 to 30 nm were coated with polyaniline using plasma polymerization and studied. The High Resolution Transmission Electron Microscopy images indicate a core shell structure after polyaniline coating and exhibited an increase in saturation magnetization by 2 emu/g. For confirmation, plasma polymerization was performed on maghemite nanoparticles which also exhibited an increase in saturation magnetization. This enhanced magnetization is rather surprising and the reason is found to be an interfacial phenomenon resulting from a contact potential.

Radio frequency plasma assisted surface modification of Fe3O4 nanoparticles using polyaniline/polypyrrole for bioimaging and magnetic hyperthermia applications

“…Agglomeration of Fe 3 O 4 nanoparticles can be prevented to a certain extent by coating a thin layer of nonmagnetic materials like graphite, polyethylene, polyvinyl alcohol, polyaniline and silica [ 2 , 12 ]. Previous studies reported the use of cross-linked polymers as a surface coating for Fe 3 O 4 nanoparticles, which resulted in the modification of its magnetic, optical and physical properties [ 13 , 14 ].…”

Amphiphilic Core–Shell Nanocomposite Particles for Enhanced Magnetic Resonance Imaging

“…These results suggest that aggregated iron oxide nanoparticles have higher saturation magnetization than those individually dispersed iron oxide nanoparticles. Therefore, encapsulation of γ‐Fe 2 O 3 nanoparticles within the polymer matrix can improve the magnetic property of the nanocomposite particles for enhanced MR imaging . To further evaluate the magnetic responsiveness of the nanocomposite particles in aqueous solution, variation in particle concentration in water before and after exposure to a magnetic field was monitored by the nanoparticle tracking analysis.…”

Influence of Particle Mass and Flow Rate on Plasma Polymerized Allylamine Coated Quartz Particles for Humic Acid Removal

“…Plasma surface modification of particles has also been undertaken using other techniques such as a fluidized bed reactor, particle injection and suspension plasma spraying . Modification of nanoparticles has also been carried out more recently using a rotating reactor, magnetic stirrer and deposition onto a planar substrate …”