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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

(Left) TEM image of Fe3O4@PAA NPs. Inset shows a brilliant field HR-STEM image of a single Fe3O4@PAA particle. (Right) Histogram corresponding to the Fe3O4@PAA NPs.
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Figure 1: (Left) TEM image of Fe3O4@PAA NPs. Inset shows a brilliant field HR-STEM image of a single Fe3O4@PAA particle. (Right) Histogram corresponding to the Fe3O4@PAA NPs.

Mentions: Morphology and crystal structure of PAA-coated magnetite nanoparticles were characterized by transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) techniques using a PHILIPS CM-12 (100 kV) and a Hitachi S-5500 (30 kV) microscopes, respectively. Figure 1 (left) shows the uniform pseudo spherical shape of magnetite@PAA MNPs. The average particle size and distribution is shown in the corresponding histogram on the right and resulted to be highly monodisperse with d = 9 ± 2 nm (85% of the total amount of particles), in good agreement with the crystalline domain size calculated from XRD results. Inset of Figure 1 (left) shows a representative high-resolution (HR) brilliant field (BF) STEM micrograph of a single particle region, showing high crystallinity and the structural homogeneity of the particles. The long range domain structure and the absence of multi-domains suggest that these nanoparticles can be considered as small single crystals. It is also evidenced that the PAA coating prevents the formation of aggregates, since they are actually well separated from each other (as deduced from the distance between the whole particle in the middle of the picture and the surrounding ones shown at the edges).


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)

(Left) TEM image of Fe3O4@PAA NPs. Inset shows a brilliant field HR-STEM image of a single Fe3O4@PAA particle. (Right) Histogram corresponding to the Fe3O4@PAA NPs.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: (Left) TEM image of Fe3O4@PAA NPs. Inset shows a brilliant field HR-STEM image of a single Fe3O4@PAA particle. (Right) Histogram corresponding to the Fe3O4@PAA NPs.
Mentions: Morphology and crystal structure of PAA-coated magnetite nanoparticles were characterized by transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) techniques using a PHILIPS CM-12 (100 kV) and a Hitachi S-5500 (30 kV) microscopes, respectively. Figure 1 (left) shows the uniform pseudo spherical shape of magnetite@PAA MNPs. The average particle size and distribution is shown in the corresponding histogram on the right and resulted to be highly monodisperse with d = 9 ± 2 nm (85% of the total amount of particles), in good agreement with the crystalline domain size calculated from XRD results. Inset of Figure 1 (left) shows a representative high-resolution (HR) brilliant field (BF) STEM micrograph of a single particle region, showing high crystallinity and the structural homogeneity of the particles. The long range domain structure and the absence of multi-domains suggest that these nanoparticles can be considered as small single crystals. It is also evidenced that the PAA coating prevents the formation of aggregates, since they are actually well separated from each other (as deduced from the distance between the whole particle in the middle of the picture and the surrounding ones shown at the edges).

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