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The influence of colloidal parameters on the specific power absorption of PAA-coated magnetite nanoparticles.

Piñeiro-Redondo Y, Bañobre-López M, Pardiñas-Blanco I, Goya G, López-Quintela MA, Rivas J - Nanoscale Res Lett (2011)

Bottom Line: The understanding of the magnetic relaxation mechanism in biocompatible nanoparticle systems is crucial in order to optimize the magnetic properties and maximize the specific absorption rate (SAR).A remarkable decrease of the SAR values with increasing particle concentration and solvent viscosity was found.These behaviours have been discussed on the basis of the magnetic relaxation mechanisms involved.PACS: 80; 87; 87.85jf.

View Article: PubMed Central - HTML - PubMed

Affiliation: Applied Physics and Physical Chemistry Departments, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain. manuel.banobre@usc.es.

ABSTRACT
The suitability of magnetic nanoparticles (MNPs) to act as heat nano-sources by application of an alternating magnetic field has recently been studied due to their promising applications in biomedicine. The understanding of the magnetic relaxation mechanism in biocompatible nanoparticle systems is crucial in order to optimize the magnetic properties and maximize the specific absorption rate (SAR). With this aim, the SAR of magnetic dispersions containing superparamagnetic magnetite nanoparticles bio-coated with polyacrylic acid of an average particle size of ≈10 nm has been evaluated separately by changing colloidal parameters such as the MNP concentration and the viscosity of the solvent. A remarkable decrease of the SAR values with increasing particle concentration and solvent viscosity was found. These behaviours have been discussed on the basis of the magnetic relaxation mechanisms involved.PACS: 80; 87; 87.85jf.

No MeSH data available.


Related in: MedlinePlus

Evolution of the specific absorption rate (SAR) of aqueous Fe3O4@PAA NPs dispersions at several concentrations between 0.6 and 20 g L-1 under an applied AC magnetic field of B = 15 mT and ν = 308 kHz. Solid line is a guide for the eye.
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Figure 3: Evolution of the specific absorption rate (SAR) of aqueous Fe3O4@PAA NPs dispersions at several concentrations between 0.6 and 20 g L-1 under an applied AC magnetic field of B = 15 mT and ν = 308 kHz. Solid line is a guide for the eye.

Mentions: In order to study the effect of the magnetite concentration on the hyperthermia properties of aqueous ferrofluids and to achieve an efficient temperature increase in the samples, we prepared two series of aqueous Fe3O4 and Fe3O4@PAA NPs based dispersions at different magnetite concentrations, ranging from 0.6 to 20 g L-1. Figure 3 shows the evolution of the SAR with magnetite concentration. The evolution of the SAR coefficient reveals that the heat production efficiency decreases with magnetite concentration for Fe3O4@PAA NPs, while a different behaviour is observed for bare Fe3O4 NPs. We associate this behaviour to the inter-particle dipole-dipole interactions, which are proportional to the particle concentration in the carrier fluid.


The influence of colloidal parameters on the specific power absorption of PAA-coated magnetite nanoparticles.

Piñeiro-Redondo Y, Bañobre-López M, Pardiñas-Blanco I, Goya G, López-Quintela MA, Rivas J - Nanoscale Res Lett (2011)

Evolution of the specific absorption rate (SAR) of aqueous Fe3O4@PAA NPs dispersions at several concentrations between 0.6 and 20 g L-1 under an applied AC magnetic field of B = 15 mT and ν = 308 kHz. Solid line is a guide for the eye.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211476&req=5

Figure 3: Evolution of the specific absorption rate (SAR) of aqueous Fe3O4@PAA NPs dispersions at several concentrations between 0.6 and 20 g L-1 under an applied AC magnetic field of B = 15 mT and ν = 308 kHz. Solid line is a guide for the eye.
Mentions: In order to study the effect of the magnetite concentration on the hyperthermia properties of aqueous ferrofluids and to achieve an efficient temperature increase in the samples, we prepared two series of aqueous Fe3O4 and Fe3O4@PAA NPs based dispersions at different magnetite concentrations, ranging from 0.6 to 20 g L-1. Figure 3 shows the evolution of the SAR with magnetite concentration. The evolution of the SAR coefficient reveals that the heat production efficiency decreases with magnetite concentration for Fe3O4@PAA NPs, while a different behaviour is observed for bare Fe3O4 NPs. We associate this behaviour to the inter-particle dipole-dipole interactions, which are proportional to the particle concentration in the carrier fluid.

Bottom Line: The understanding of the magnetic relaxation mechanism in biocompatible nanoparticle systems is crucial in order to optimize the magnetic properties and maximize the specific absorption rate (SAR).A remarkable decrease of the SAR values with increasing particle concentration and solvent viscosity was found.These behaviours have been discussed on the basis of the magnetic relaxation mechanisms involved.PACS: 80; 87; 87.85jf.

View Article: PubMed Central - HTML - PubMed

Affiliation: Applied Physics and Physical Chemistry Departments, University of Santiago de Compostela, Santiago de Compostela, 15782, Spain. manuel.banobre@usc.es.

ABSTRACT
The suitability of magnetic nanoparticles (MNPs) to act as heat nano-sources by application of an alternating magnetic field has recently been studied due to their promising applications in biomedicine. The understanding of the magnetic relaxation mechanism in biocompatible nanoparticle systems is crucial in order to optimize the magnetic properties and maximize the specific absorption rate (SAR). With this aim, the SAR of magnetic dispersions containing superparamagnetic magnetite nanoparticles bio-coated with polyacrylic acid of an average particle size of ≈10 nm has been evaluated separately by changing colloidal parameters such as the MNP concentration and the viscosity of the solvent. A remarkable decrease of the SAR values with increasing particle concentration and solvent viscosity was found. These behaviours have been discussed on the basis of the magnetic relaxation mechanisms involved.PACS: 80; 87; 87.85jf.

No MeSH data available.


Related in: MedlinePlus