Investigating the effective interaction between silica colloidal particles near the critical point of a binary solvent by small angle neutron scattering

2018 ◽  
Vol 149 (8) ◽  
pp. 084905
Author(s):  
Zhiyuan Wang ◽  
Hongyu Guo ◽  
Yun Liu ◽  
Xuewu Wang
Keyword(s):  
Neutron Scattering ◽  
Critical Point ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Colloidal Particles ◽  
Effective Interaction ◽  
Binary Solvent

Spin-echo small-angle neutron scattering device: Test experiment using SiO2 colloidal particles

2013 ◽  
Vol 7 (3) ◽  
pp. 401-406 ◽  
Author(s):  
E. V. Velichko ◽  
Yu. O. Chetverikov ◽  
L. A. Aksel’rod ◽  
V. N. Zabenkin ◽  
V. V. Piyadov ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Colloidal Particles ◽  
Spin Echo ◽  
Test Experiment ◽  
Device Test

Application of small-angle neutron scattering to the study of forces between magnetically chained monodisperse ferrofluid emulsion droplets

2013 ◽  
Vol 47 (1) ◽  
pp. 41-52 ◽  
Author(s):  
N. Jain ◽  
C. K. Liu ◽  
B. S. Hawkett ◽  
G. G. Warr ◽  
W. A. Hamilton
Keyword(s):  
Magnetic Field ◽  
Neutron Scattering ◽  
Droplet Size ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Colloidal Particles ◽  
Optical Measurements ◽  
Magnetic Field Direction ◽  
Emulsion Droplets ◽  
The Magnetic Field

The optical magnetic chaining technique (MCT) developed by Leal-Calderon, Stora, Mondain-Monval, Poulin & Bibette [Phys. Rev. Lett.(1994),72, 2959–2962] allows precise measurements of force profiles between droplets in monodisperse ferrofluid emulsions. However, the method lacks anin situdetermination of droplet size and, therefore, requires a combination of separately acquired measurements of droplet chain periodicityversusan applied magnetic field from optical Bragg scattering and droplet diameter inferred from dynamic light scattering (DLS) to recover surface force–distance profiles between the colloidal particles. Compound refractive lens (CRL) focused small-angle neutron scattering (SANS) MCT should result in more consistent measurements of droplet size (form factor measurements in the absence of field) and droplet chaining period (from structure factor peaks when the magnetic field is applied), and, with access to shorter length scales, extend force measurements to closer approaches than possible by optical measurements. This article reports on CRL-SANS measurements of monodisperse ferrofluid emulsion droplets aligned in straight chains by an applied field perpendicular to the incident beam direction. Analysis of the scattering from the closely spaced droplets required algorithms that carefully treated resolution and its effect on mean scattering vector magnitudes in order to determine droplet size and chain periods to sufficient accuracy. At lower applied fields, scattering patterns indicate structural correlations transverse to the magnetic field direction owing to the formation of intermediate structures in early chain growth.

A new approach for probing matter in periodic nanoconfinements using neutron scattering

2014 ◽  
Vol 47 (4) ◽  
pp. 1367-1373 ◽  
Author(s):  
Rana Ashkar ◽  
Roger Pynn ◽  
Robert Dalgliesh ◽  
Nickolay V. Lavrik ◽  
Ivan I. Kravchenko
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Diffraction Grating ◽  
Small Angle Neutron Scattering ◽  
Colloidal Particles ◽  
Spin Echo ◽  
Dynamical Theory ◽  
Silica Particles ◽  
New Approach ◽  
Homogenous Distribution

The efficacy of spin-echo small-angle neutron scattering (SESANS) combined with an exact dynamical theory (DT) model in resolving the arrangement of spherical colloidal particles in planar confinements, such as the channels of a rectangular diffraction grating, is reported. SESANS data obtained with a suspension of charge-stabilized 180 nm silica particles in contact with a silicon diffraction grating, with ∼650 nm-wide channels, show clear deviations from the signal expected from a homogenous distribution of the suspension. DT fits to the data indicate that the colloidal particles are almost twice as concentrated in the channels as they are in the neighboring bulk suspension, consistent with a structure in which the particles are arranged in close-packed sheets parallel to the walls of the confining channels.

Structure of water-based ferrofluids with sodium oleate and polyethylene glycol stabilization by small-angle neutron scattering: contrast-variation experiments

2010 ◽  
Vol 43 (5) ◽  
pp. 959-969 ◽  
Author(s):  
Mikhail V. Avdeev ◽  
Artem V. Feoktystov ◽  
Peter Kopcansky ◽  
Gabor Lancz ◽  
Vasil M. Garamus ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Neutron Scattering ◽  
Sodium Oleate ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Colloidal Particles ◽  
Micelle Formation ◽  
Magnetic Scattering ◽  
Contrast Variation ◽  
Water Based

Contrast variation in small-angle neutron scattering (SANS) experiments is used to compare the structures of a water-based ferrofluid, where magnetite nanoparticles are stabilized by sodium oleate, and its mixture with biocompatible polyethylene glycol, PEG. The basic functions approach is applied, which takes into account the effects of polydispersity and magnetic scattering. Different types of stable aggregates of colloidal particles are revealed in both fluids. The addition of PEG results in a reorganization of the structure of the aggregates: the initial comparatively small and compact aggregates (about 40 nm in size) are replaced by large (more than 120 nm in size) fractal-type structures. It is postulated that these large structures are composed of single magnetite particles coated with PEG, which replaces sodium oleate. Micelle formation involving free sodium oleate is observed in both fluids. The structures of the fluids remain unchanged with increasing temperature up to 343 K. New and specific possibilities of SANS contrast variation with respect to multicomponent systems with different aggregates are considered.

Small-angle neutron scattering from heavy water in the vicinity of the critical point

2000 ◽  
Vol 112 (1) ◽  
pp. 268-274 ◽  
Author(s):  
M. Bonetti ◽  
G. Romet-Lemonne ◽  
P. Calmettes ◽  
M.-C. Bellissent-Funel
Keyword(s):  
Neutron Scattering ◽  
Critical Point ◽  
Heavy Water ◽  
Small Angle ◽  
Small Angle Neutron Scattering

Small Angle Neutron Scattering Studies of Asphaltic Materials

1994 ◽  
Vol 376 ◽  
Author(s):  
D. A. Storm ◽  
E. Y. Sheu
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Colloidal Particles ◽  
Dispersed Phase ◽  
X Ray Scattering ◽  
Surface Active Agents ◽  
Surface Active ◽  
Road Asphalts ◽  
Asphaltic Materials

ABSTRACTAsphaltic materials are used as binders for road asphalts. Such materials have been found to contain a dispersed phase of colloidal particles in the size range of 50-100 Å, according to small angle X-ray scattering(SAXS) techniques. The presence of this dispersed phase has a significant influence on the rheological properties of these materials. These colloidal particles can be isolated by precipitation with heptane, and so they are associated with the well-known asphaltene solubility class in some manner. In this work we review previously published results that suggest that at least part of the asphaltenes are surface active agents in certain solvents such as toluene, or pyridine, and can form micelles in these solvents. Small angle neutron scattering (SANS) indicates the micelles are spherical with average radii in the 50-100 Å range. There is a polydispersity of sizes. The micelles do not grow in these solvents with increasing concentration in the range of 1-10 wt.%, nor do they dissociate on heating to ~ 170 °C. At higher concentrations, however, a more complicated structure develops. The micelles aggregate to form a large cluster composed of micelles. The fractal dimension of the clusters is found to be 1.8.

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