scholarly journals Small Angle Neutron Scattering from Nanophase Titanium As A Function of Oxidation

1988 ◽  
Vol 132 ◽  
Author(s):  
J. A. Eastman ◽  
J. E. Epperson ◽  
H. Hahn ◽  
T. E. Klippert ◽  
A. Narayanasamy ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Scattering Length ◽  
Contrast Variation ◽  
Gas Condensation ◽  
Pressure Oxygen ◽  
Scattering Centers ◽  
Scattering Lengths ◽  
Contrast Matching

ABSTRACTNanophase titanium, prepared by the gas-condensation method both as aggregated powder and in lightly compacted discs, has been studied by conventional small angle neutron scattering, and by use of contrast variation methods. The contrast has been changed (a), isotopically, by means of deuterated/protonated solvents distilled into the specimen and (b) by progressive incremental oxidation of the Ti particles using fixed doses of low-pressure oxygen. It was shown that some evolution of the small angle pattern for lightly compacted nanophase Ti occurred over a period of several months at 300 K. Contrast matching by external solvent works well and has allowed the scattering lengths of oxidized and unoxidized specimens to be followed. The results imply that the scattering from metal and oxide can be separated under suitable conditions. The partial oxidation experiments indicate that there is both a fast and slow oxidation at 300 K. Also, during slow oxidation, high scattering length density scattering centers were formed whose number increased, but whose size remained the same at about 2 nm; these centers are tentatively assumed to be TiO2.

scholarly journals Variation of Solvent Scattering-Length Density in Small-Angle Neutron Scattering as a Means of Determining Structure of Composite Materials

1994 ◽  
Vol 376 ◽  
Author(s):  
Rex P. Hjelm ◽  
Wesley Wampler ◽  
Michel Gerspacher
Keyword(s):  
Composite Materials ◽  
Carbon Black ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Scattering Length ◽  
Contrast Variation ◽  
Length Scales ◽  
Excluded Volume Effects ◽  
Component Form

ABSTRACTAs part of our work on the structure of composite materials we have been exploring the use of small-angle neutron scattering using the method of contrast variation to dissect the component form, structure and distribution. This approach has resulted in a new look at very old problemreinforcement of elastomers by carbon black.Using this approach we studied an experimental high surface area (HSA) carbon black and a gel of "HSA-bound" rubber in cyclohexane/deuterocyclohexane mixtures. HSA in cyclohexane is found to be short rodlike particle aggregates. The aggregates have a shell-core structure with a high density graphitic outer shell and an inner core of lower density amorphous carbon. The core is continuous throughout the carbon black aggregate, making the aggregate a stiff, integral unit. Contrast variation of swollen composite gels shows that there are two length scales in the gel structure. Above 10 Å, scattering from carbon black predominates, and below 10 Å the scattering is from both carbon black and the elastomer. The HSA in the composite is completely embedded in polyisoprene. An estimate of the carbon black structure factor shows strong exclusion of neighboring aggregates, probably from excluded volume effects. The surface structure of the carbon black is unaltered by the interactions with elastomer and appears smooth over length scales above about 10 Å. These results show that contrast variation can provide information on composite structure that is not available by other means. This information relates to the reinforcement mechanism of elastomers by carbon blacks.

Small-angle neutron scattering analysis of a water-based magnetic fluid with charge stabilization: contrast variation and scattering of polarized neutrons

2009 ◽  
Vol 42 (6) ◽  
pp. 1009-1019 ◽  
Author(s):  
Mikhail V. Avdeev ◽  
Emmanuelle Dubois ◽  
Guillaume Mériguet ◽  
Elie Wandersman ◽  
Vasil M. Garamus ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Magnetic Fluid ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Scattering Length ◽  
Magnetic Scattering ◽  
Contrast Variation ◽  
Polarized Neutrons ◽  
Scattering Length Density ◽  
Charge Stabilization

Structure analysis of a magnetic fluid (nanoparticles of maghemite dispersed in water with charge stabilization and without surfactant) by means of small-angle neutron scattering is presented. A combination of the contrast variation technique and scattering of polarized neutrons was applied. In the first case, the scattering curves obtained for the unmagnetized fluid with variation of the heavy water content in the carrier are treated in terms of the basic functions approach. The almost homogeneous character of the nanoparticles with respect to the nuclear scattering length density makes it possible to separate information about their characteristic nuclear and magnetic radii. Polarized neutrons are then used to separate and analyze independently the nuclear and magnetic scattering contributions for the fully magnetized fluid. Both methods reveal a significant excess of the apparent nuclear size over the magnetic one, which is explained by a difference in the nonmagnetic and magnetic interactions in the system. The results indicate that from the viewpoint of magnetic interaction the studied fluid behaves under a magnetic field as a purely superparamagnetic system of independent particles. The magnetic scattering length density of the maghemite nanoparticles is found to be ∼25% less than the bulk value, which is in agreement with the data of the magnetization analysis.

STRUCTURE ANALYSES OF SWOLLEN RUBBER–CARBON BLACK SYSTEMS BY USING CONTRAST VARIATION SMALL-ANGLE NEUTRON SCATTERING

2012 ◽  
Vol 85 (2) ◽  
pp. 157-164 ◽  
Author(s):  
Mikihito Takenaka ◽  
Shotaro Nishitsuji ◽  
Naoya Amino ◽  
Yasuhiro Ishikawa ◽  
Daisuke Yamaguchi ◽  
...  
Keyword(s):  
Carbon Black ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Adsorption Layer ◽  
Scattering Length ◽  
Scattering Function ◽  
Characteristic Parameters ◽  
Contrast Variation ◽  
Polymer Layers

Abstract In a previous study [Takenaka et al., Macromolecules 42, 308 (2009)], we have investigated the polymer layers absorbed on silica (Si) particles in rubber–Si systems with the contrast variation small-angle neutron scattering (SANS) method. We have investigated the polymer layers absorbed on carbon black (CB) particles in rubber–CB systems with contrast variation SANS method. The scattering intensities of specimens swollen by the solvents having various scattering length densities were measured. The contrast variation SANS for the specimens yielded partial scattering functions: the scattering function for polymer–polymer correlation SPP(q), the scattering function for CB–CB correlation SCC(q), and the scattering function for polymer–CB correlation SPC(q). The analyses of SCC(q) explored the structures of the aggregates formed by CB particles. The analyses of SPC(q) and SCC(q) clarified the existence of dense polymer layers around CB aggregates. Several characteristic parameters are estimated from the analyses, such as the size of aggregates, the thickness of layers, and the volume fractions of polymer layers and matrix. We found that the adsorption layer around CB aggregates is thicker than that around Si aggregates in rubber–Si systems.

Rapid contrast matching by microfluidic SANS

Lab on a Chip ◽  
2017 ◽  
Vol 17 (9) ◽  
pp. 1559-1569 ◽  
Author(s):  
Marco Adamo ◽  
Andreas S. Poulos ◽  
Ruhina M. Miller ◽  
Carlos G. Lopez ◽  
Anne Martel ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Contrast Variation ◽  
Biological Matter ◽  
Contrast Matching

We report a microfluidic approach to perform small angle neutron scattering (SANS) measurements of contrast variation and matching, extensively employed in soft and biological matter research.

Ultra-Small-Angle Neutron Scattering Study of Colloidal Alloys. 1. Contrast Variation Experiments for Mixtures of Hydrogenated and Deuterated Polystyrene Latices in H2O/D2O

Langmuir ◽  
1999 ◽  
Vol 15 (2) ◽  
pp. 293-296 ◽  
Author(s):  
Hideki Matsuoka ◽  
Takashi Ikeda ◽  
Hitoshi Yamaoka ◽  
Mitsuhiro Hashimoto ◽  
Toshio Takahashi ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Contrast Variation ◽  
Scattering Study ◽  
Neutron Scattering Study

Mechanically Interlocked Structure of Polyrotaxane Investigated by Contrast Variation Small-Angle Neutron Scattering

2009 ◽  
Vol 42 (16) ◽  
pp. 6327-6329 ◽  
Author(s):  
Koichi Mayumi ◽  
Hitoshi Endo ◽  
Noboru Osaka ◽  
Hideaki Yokoyama ◽  
Michihiro Nagao ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Contrast Variation

Use of contrast matching small-angle neutron scattering to monitor the presence of closed porosity in controlled porosity styrene–divinylbenzene resins

1996 ◽  
Vol 92 (14) ◽  
pp. 2607-2610 ◽  
Author(s):  
Peter J. Hall ◽  
Wilson Ruiz Machado ◽  
David Gascon Galan ◽  
Elizabeth Barrientos Barria ◽  
David C. Sherrington
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Closed Porosity ◽  
Styrene Divinylbenzene ◽  
Controlled Porosity ◽  
Contrast Matching

Small angle neutron scattering experiments on nanostructured matter using contrast variation

1997 ◽  
Vol 9 (1-8) ◽  
pp. 327-330
Author(s):  
S. Janßen ◽  
J. Wagner ◽  
H. Natter ◽  
J. Prewo ◽  
R. Rupp ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Contrast Variation

Structure of Nanocomposite Hydrogel Investigated by Means of Contrast Variation Small-Angle Neutron Scattering

2008 ◽  
Vol 41 (14) ◽  
pp. 5406-5411 ◽  
Author(s):  
Hitoshi Endo ◽  
Sho Miyazaki ◽  
Kazutoshi Haraguchi ◽  
Mitsuhiro Shibayama
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Nanocomposite Hydrogel ◽  
Contrast Variation

scholarly journals The use of small angle neutron scattering with contrast matching and variable adsorbate partial pressures in the study of porosity in activated carbons

Carbon ◽  
2012 ◽  
Vol 50 (14) ◽  
pp. 5062-5075 ◽  
Author(s):  
Z. Mileeva ◽  
D.K. Ross ◽  
D. Wilkinson ◽  
S.M. King ◽  
T.A. Ryan ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Activated Carbons ◽  
Partial Pressures ◽  
Contrast Matching
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