scholarly journals Development of Dynamic Nuclear Polarization System for Spin-Contrast-Variation Neutron Reflectometry

2018 ◽  
Author(s):  
Takayuki Kumada ◽  
Kazuhiro Akutsu ◽  
Kazuki Ohishi ◽  
Toshiaki Morikawa ◽  
Yukihiko Kawamura ◽  
...  
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Neutron Reflectometry ◽  
Contrast Variation

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 Development of closed -cycle dynamic nuclear polarization system for small -angle neutron scattering and neutron reflectometry

2018 ◽  
Author(s):  
Takayuki Kumada ◽  
Kazuhiro Akutsu ◽  
Kazuki Ohishi ◽  
Yukihiko Kawamura ◽  
Toshiaki Morikawa ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Dynamic Nuclear Polarization ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Nuclear Polarization ◽  
Neutron Reflectometry ◽  
Closed Cycle

scholarly journals Contrast Variation Small Angle Neutron Scattering by Dynamic Nuclear Polarization: A Case of Time-of-Flight Method in J-PARC

hamon ◽  
2015 ◽  
Vol 25 (3) ◽  
pp. 214-221
Author(s):  
Yohei Noda ◽  
Satoshi Koizumi ◽  
Tomomi Masui ◽  
Ryo Mashita ◽  
Hiroyuki Kishimoto ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Dynamic Nuclear Polarization ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Nuclear Polarization ◽  
Time Of Flight ◽  
Contrast Variation ◽  
Time Of Flight Method

Porphyrins as Versatile, Aggregation-Tolerant, and Biocompatible Polarizing Agents for Triplet Dynamic Nuclear Polarization of Biomolecules

2021 ◽  
pp. 2645-2650
Author(s):  
Tomoyuki Hamachi ◽  
Koki Nishimura ◽  
Hironori Kouno ◽  
Yusuke Kawashima ◽  
Kenichiro Tateishi ◽  
...  
Keyword(s):  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization

Solvent-free dynamic nuclear polarization enhancements in organically modified mesoporous silica

2021 ◽  
Author(s):  
Marcos de Oliveira Jr. ◽  
Kevin Herr ◽  
Martin Brodrecht ◽  
Nadia Berenice Haro-Mares ◽  
Till Wissel ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Porous Materials ◽  
Structural Characterization ◽  
Dynamic Nuclear Polarization ◽  
High Field ◽  
Nuclear Polarization ◽  
Organically Modified ◽  
Field Dynamic ◽  
Free Dynamic

High-field Dynamic Nuclear Polarization is a powerful tool for the structural characterization of species on the surface of porous materials or nanoparticles. For these studies the main source of polarization...

scholarly journals Dynamic Nuclear Polarization of Silicon Carbide Micro- and Nanoparticles

2021 ◽  
Author(s):  
Min Lin ◽  
Vincent Breukels ◽  
Tom W. J. Scheenen ◽  
Jos M. J. Paulusse
Keyword(s):  
Silicon Carbide ◽  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization

scholarly journals Dynamic Nuclear Polarization / solid-state NMR of membranes. Thermal effects and sample geometry

2019 ◽  
Vol 100 ◽  
pp. 70-76 ◽  
Author(s):  
Evgeniy Sergeevich Salnikov ◽  
Fabien Aussenac ◽  
Sebastian Abel ◽  
Armin Purea ◽  
Paul Tordo ◽  
...  
Keyword(s):  
Solid State ◽  
Dynamic Nuclear Polarization ◽  
Thermal Effects ◽  
Solid State Nmr ◽  
Nuclear Polarization ◽  
Sample Geometry
Sign in / Sign up

Export Citation Format

Share Document