On the synthesis and magnetic properties of multiwall carbon nanotube–superparamagnetic iron oxide nanoparticle nanocomposites

Abstract

Multiwall carbon nanotubes (MWCNTs) possessing an average inner diameter of 150 nm were synthesized by template assisted chemical vapor deposition over an alumina template. Aqueous ferrofluid based on superparamagnetic iron oxide nanoparticles (SPIONs) was prepared by a controlled co-precipitation technique, and this ferrofluid was used to fill the MWCNTs by nanocapillarity. The filling of nanotubes with iron oxide nanoparticles was confirmed by electron microscopy. Selected area electron diffraction indicated the presence of iron oxide and graphitic carbon from MWCNTs. The magnetic phase transition during cooling of the MWCNT-SPION composite was investigated by low temperature magnetization studies and zero field cooled (ZFC) and field cooled experiments. The ZFC curve exhibited a blocking at ∼110 K. A peculiar ferromagnetic ordering exhibited by the MWCNT-SPION composite above room temperature is because of the ferromagnetic interaction emanating from the clustering of superparamagnetic particles in the constrained volume of an MWCNT. This kind of MWCNT-SPION composite can be envisaged as a good agent for various biomedical applications.

Synthesis of Bio-Compatible SPION–based Aqueous Ferrofluids and Evaluation of RadioFrequency Power Loss for Magnetic Hyperthermia

“…This is further verified by fitting experimental curve with the modified Langevin function [21] for the particles with normal size distribution (Fig. 4).…”

Collagen based magnetic nanocomposites for oil removal applications

“…The obtained dry hide powder can be stored in a closed plastic bag for several months. Fe 3 O 4 based ferrofluids were prepared by chemical co-precipitation method as detailed elsewhere17. The SPIONs (Fe 3 O 4 nanoparticles having size ∼10 nm) coated with citric acid organic hull were dispersed in distilled water by extensive sonication to yield 0.1 g/ml SPION solution.…”

“…Interaction of nanoparticles with collagen fibers is an upcoming and stimulating research area1415. Aqueous suspensions of magnetic Fe 3 O 4 nanoparticles161718 of uniform particle size (∼10 nm), known as ferrofluid (FF), could be an interesting candidate for exploiting such interactions.…”

Highly crystalline superparamagnetic iron oxide nanoparticles (SPION) in a silica matrix

“…Consequently, preparation of the magnetic nanoparticles requires several tasks, such as control of the size and size distribution of the particles, control of the morphology and crystallinity, and prevention of the agglomeration. Different preparation methods have been developed in order to obtain desirable samples and physical properties: hydrothermal, sol-gel, solvothermal, mechanochemical, polyol process, co-precipitation, template, thermal decomposition, spray pyrolysis, chemical vapour deposition, carbothermal reduction, electro-precipitation, microwave plasma synthesis, ␥-irradiated water-in-oil microemulsion, melt quench technique, microemulsion and reverse microemulsion technique [1,48,59,62,68,70,[73][74][75][76][77][78][79][80]. Among them the sol-gel method has been shown to be very useful for preparation of iron oxide nanoparticles dispersed in an amorphous silica matrix.…”