Analysis of Surface Structure and Hydrogen/Deuterium Exchange of Colloidal Silica Suspension by Contrast-Variation Small-Angle Neutron Scattering

Langmuir ◽  
2008 ◽  
Vol 24 (9) ◽  
pp. 4537-4543 ◽  
Author(s):  
Takuya Suzuki ◽  
Hitoshi Endo ◽  
Mitsuhiro Shibayama
Keyword(s):  
Neutron Scattering ◽  
Surface Structure ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Colloidal Silica ◽  
Deuterium Exchange ◽  
Hydrogen Deuterium Exchange ◽  
Contrast Variation ◽  
Silica Suspension ◽  
Hydrogen Deuterium

scholarly journals PSX, Protein–Solvent Exchange: software for calculation of deuterium-exchange effects in small-angle neutron scattering measurements from protein coordinates

2019 ◽  
Vol 52 (6) ◽  
pp. 1427-1436
Author(s):  
Martin Cramer Pedersen ◽  
Yong Wang ◽  
Frederik Grønbæk Tidemand ◽  
Anne Martel ◽  
Kresten Lindorff-Larsen ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Deuterium Exchange ◽  
Biological Macromolecules ◽  
Hydrogen Atoms ◽  
Experimental Conditions ◽  
Sample Handling ◽  
Recent Developments ◽  
Hydrogen Deuterium

Recent developments in neutron scattering instrumentation and sample handling have enabled studies of more complex biological samples and measurements at shorter exposure times. The experiments are typically conducted in D2O-based buffers to emphasize or diminish scattering from a particular component or to minimize background noise in the experiment. To extract most information from such experiments it is thus desirable to determine accurate estimates of how and when closely bound hydrogen atoms from the biomolecule exchange with the deuterium in the solvent. This article introduces and documents software, PSX, for exploring the effect of hydrogen–deuterium exchange for proteins solubilized in D2O as well as the underlying bioinformatical models. The software aims to be generally applicable for any atomistic structure of a protein and its surrounding environment, and thus captures effects of both heterogenous exchange rates throughout the protein structure and varying the experimental conditions such as pH and temperature. The paper concludes with examples of applications and estimates of the effect in typical scenarios emerging in small-angle neutron scattering on biological macromolecules in solution. The analysis presented here suggests that the common assumption of 90% exchange is in many cases an overestimate with the rapid sample handling systems currently available, which leads to fitting and calibration issues when analysing the data. Source code for the presented software is available from an online repository in which it is published under version 3 of the GNU publishing licence.

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

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 Amphiphilic Comb Polymers as New Additives in Bicontinuous Microemulsions

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2410
Author(s):  
Debasish Saha ◽  
Karthik R. Peddireddy ◽  
Jürgen Allgaier ◽  
Wei Zhang ◽  
Simona Maccarrone ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Amphiphilic Polymers ◽  
Side Chain ◽  
Side Chains ◽  
Contrast Variation ◽  
Dna Complexes ◽  
Comb Polymers ◽  
Polymer Architectures

It has been shown that the thermodynamics of bicontinuous microemulsions can be tailored via the addition of various different amphiphilic polymers. In this manuscript, we now focus on comb-type polymers consisting of hydrophobic backbones and hydrophilic side chains. The distinct philicity of the backbone and side chains leads to a well-defined segregation into the oil and water domains respectively, as confirmed by contrast variation small-angle neutron scattering experiments. This polymer–microemulsion structure leads to well-described conformational entropies of the polymer fragments (backbone and side chains) that exert pressure on the membrane, which influences the thermodynamics of the overall microemulsion. In the context of the different polymer architectures that have been studied by our group with regards to their phase diagrams and small-angle neutron scattering, the microemulsion thermodynamics of comb polymers can be described in terms of a superposition of the backbone and side chain fragments. The denser or longer the side chain, the stronger the grafting and the more visible the brush effect of the side chains becomes. Possible applications of the comb polymers as switchable additives are discussed. Finally, a balanced philicity of polymers also motivates transmembrane migration in biological systems of the polymers themselves or of polymer–DNA complexes.

scholarly journals Contrast variation by dynamic nuclear polarization and time-of-flight small-angle neutron scattering. I. Application to industrial multi-component nanocomposites

2016 ◽  
Vol 49 (6) ◽  
pp. 2036-2045 ◽  
Author(s):  
Yohei Noda ◽  
Satoshi Koizumi ◽  
Tomomi Masui ◽  
Ryo Mashita ◽  
Hiroyuki Kishimoto ◽  
...  
Keyword(s):  
Form Factor ◽  
Binary Mixture ◽  
Neutron Scattering ◽  
Dynamic Nuclear Polarization ◽  
Small Angle ◽  
Ternary Mixture ◽  
Small Angle Neutron Scattering ◽  
Nuclear Polarization ◽  
Scattering Function ◽  
Contrast Variation

Dynamic nuclear polarization (DNP) at low temperature (1.2 K) and high magnetic field (3.3 T) was applied to a contrast variation study in small-angle neutron scattering (SANS) focusing on industrial rubber materials. By varying the scattering contrast by DNP, time-of-flight SANS profiles were obtained at the pulsed neutron source of the Japan Proton Accelerator Research Complex (J-PARC). The concentration of a small organic molecule, (2,2,6,6-tetramethylpiperidine-1-yl)oxy (TEMPO), was carefully controlled by a doping method using vapour sorption into the rubber specimens. With the assistance of microwave irradiation (94 GHz), almost full polarization of the paramagnetic electronic spin of TEMPO was transferred to the spin state of hydrogen (protons) in the rubber materials to obtain a high proton spin polarization (PH). The following samples were prepared: (i) a binary mixture of styrene–butadiene random copolymer (SBR) with silica particles (SBR/SP); and (ii) a ternary mixture of SBR with silica and carbon black particles (SBR/SP/CP). For the binary mixture (SBR/SP), the intensity of SANS significantly increased or decreased while keeping itsqdependence forPH= −35% orPH= 40%, respectively. Theqbehaviour of SANS for the SBR/SP mixture can be reproduced using the form factor of a spherical particle. The intensity at lowq(∼0.01 Å−1) varied as a quadratic function ofPHand indicated a minimum value atPH= 30%, which can be explained by the scattering contrast between SP and SBR. The scattering intensity at highq(∼0.3 Å−1) decreased with increasingPH, which is attributed to the incoherent scattering from hydrogen. For the ternary mixture (SBR/SP/CP), theqbehaviour of SANS was varied by changingPH. AtPH= −35%, the scattering maxima originating from the form factor of SP prevailed, whereas atPH= 29% andPH= 38%, the scattering maxima disappeared. After decomposition of the total SANS according to inverse matrix calculations, the partial scattering functions were obtained. The partial scattering function obtained for SP was well reproduced by a spherical form factor and matched the SANS profile for the SBR/SP mixture. The partial scattering function for CP exhibited surface fractal behaviour according toq−3.6, which is consistent with the results for the SBR/CP mixture.

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.

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