Small-angle X-ray and small-angle neutron scattering investigations of colloidal dispersions of magnetic nanoparticles and clay nanoplatelets

Paula, Fábio Luís de Oliveira; Aquino, Renata; Silva, G.J. da; Depeyrot, J.; Tourinho, F.A.; Fossum, Jon Otto; Knudsen, Kenneth D.

doi:10.1107/s0021889807009181

Cited by 14 publications

(9 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For the particle size distribution of the magnetic nanoparticles, the lognormal function is the best model to describe the size distribution of the particle radii [33]. For spherical particles with a diameter, D = 2R, it is modified from [34] …”

Section: Resultsmentioning

confidence: 99%

Nanoscale Clustering and Magnetic Properties of Mn x Fe3−x O4 Particles Prepared from Natural Magnetite

Taufiq

Sunaryono

Putra

et al. 2015

J Supercond Nov Magn

View full text Add to dashboard Cite

A series of Mn x Fe 3−x O 4 (0 ≤ x ≤ 1) nanoparticles was successfully synthesized via a simple coprecipitation method. The starting material was a natural magnetite purified from local iron sand. Crystallite nanoparticles were produced by drying without using a high calcination temperature. Rietveld analysis of the X-ray diffractometry (XRD) data for all samples demonstrated that the Mn ions partially substituted the Fe ions in the spinel cubic structure of the Fe 3 O 4 to form Mn x Fe 3−x O 4 phases. We applied two lognormal spherical and single mass fractal models to the analysis of the small-angle neutron scattering (SANS) data and revealed that the primary Mn x Fe 3−x O 4 particles ranged in size from 1.5 to 3.8 nm and formed three-dimensional Darminto

show abstract

Section: Resultsmentioning

confidence: 99%

Nanoscale Clustering and Magnetic Properties of Mn x Fe3−x O4 Particles Prepared from Natural Magnetite

Taufiq

Sunaryono

Putra

et al. 2015

J Supercond Nov Magn

View full text Add to dashboard Cite

show abstract

“…These models were successfully used to characterize a disordered cluster structure [19], a fractal mass of particles [20] as well as to distinguish between individual polydispersed particles and aggregates [21]. This work aims to investigate the local structure of magnetic colloids [22] under external magnetic field application, the colloids in question are composed of magnetic nanoparticles based on manganese ferrite type core-shell MnFe 2 O 4+δ @γ-Fe 2 O 3 [23] and dispersed in aqueous medium. SAXS measurements were performed with external magnetic field applied [24] to determine the dimensions between nanoparticles and clusters [25], for future studies in hyperthermia [26] for biomedical applications.…”

Section: Introductionmentioning

confidence: 99%

SAXS Analysis of Magnetic Field Influence on Magnetic Nanoparticle Clusters

Paula

2019

Condensed Matter

View full text Add to dashboard Cite

In this work, we investigated the local colloidal structure of ferrofluid, in the presence of the external magnetic field. The nanoparticles studied here are of the core-shell type, with the core formed by manganese ferrite and maghemite shell, and were synthesized by the coprecipitation method in alkaline medium. Measures of Small Angle X-ray Scattering (SAXS) performed in the Brazilian Synchrotron Light Laboratory (LNLS) were used for the study of the local colloidal structure of ferrofluid, so it was possible to study two levels of structure, cluster and isolated particles, in the regimes with and without applied magnetic field. In the methodology used here there is a combination of the information obtained in the system with and without magnetic field application. In this way, it is possible to undertake a better investigation of the colloidal dispersion. The theoretical formalism used: (i) the unification equation proposed by Beaucage G.; (ii) the analysis of the radial distribution function p ( r ) and (iii) theoretical calculation of the radius of gyration as a function of the moment of inertia of the spherical of n-nanoparticles.

show abstract

“…In the expression for λ, d h is the hydrodynamic diameter of the particle which is greater than the size of the magnetic core, d, by twice the thickness of protective surfactant layer [2]. Detecting the particle aggregation is a e-mail: zbigniew.rozynek@ntnu.no possible only by indirect experimental methods based on magnetorelaxometry [3], viscosity [4,5], ultrasound attenuation measurements [6], or SANS/SAXS [7][8][9] performed in external magnetic field.…”

Section: Introductionmentioning

confidence: 99%

Structuring from nanoparticles in oil-based ferrofluids

Rozynek

Józefczak²,

Knudsen

et al. 2011

Eur. Phys. J. E

Self Cite

View full text Add to dashboard Cite

The effect of magnetic field on the structure formation in an oil-based magnetic fluid with various concentrations of magnetite particles was studied. The evaluation of the experimental data obtained from small-angle X-ray scattering and ultrasonic attenuation indicates the formation of chain-like aggregates composed of magnetite particles. The experimental data obtained from ultrasonic spectroscopy fit well with the recent theoretical model by Shliomis, Mond and Morozov but only for a diluted magnetic fluid. In this model it is assumed that a dimer is the main building block of a B -field-induced chain-like structure, thus the estimation of the nematic order parameter does not depend on the actual length of the structure. The scattering method used reveals information about the aggregated structure size and relative changes in the degree of anisotropy in qualitative terms. The coupling constant [Formula: see text] , concentrations [Formula: see text] , average particle size d and its polydispersity [Formula: see text] were initially obtained using the vibrating sample magnetometry and these results were further confirmed by rheometry and scattering methods. Both the particles' orientational distribution and the nematic order parameter S were inferred from the ultrasonic measurements. The investigation of SAXS patterns reveals the orientation and sizes of aggregated structures under application of different magnetic-field strengths. In addition, the magnetic-field-dependent yield stress was measured, and a relationship between the yield stress and magnetic-field strength up to 0.5 T was established.

show abstract

Small-angle X-ray and small-angle neutron scattering investigations of colloidal dispersions of magnetic nanoparticles and clay nanoplatelets

Cited by 14 publications

References 17 publications

Nanoscale Clustering and Magnetic Properties of Mn x Fe3−x O4 Particles Prepared from Natural Magnetite

Nanoscale Clustering and Magnetic Properties of Mn x Fe3−x O4 Particles Prepared from Natural Magnetite

SAXS Analysis of Magnetic Field Influence on Magnetic Nanoparticle Clusters

Structuring from nanoparticles in oil-based ferrofluids

Contact Info

Product

Resources

About