Small Angle Neutron Scattering Studies of Blends of Protonated Linear Polystyrene with Crosslinked Deuterated Polystyrene

1989 ◽  
Vol 171 ◽  
Author(s):  
Robert M. Briber ◽  
Barry J. Bauer
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Crosslink Density ◽  
Single Phase ◽  
Linear Chain ◽  
Free Energies ◽  
Scattering Function ◽  
Angle Scattering ◽  
Divinyl Benzene

ABSTRACTSmall angle neutron scattering (SANS) has been used to study the scattering function and thermodynamics of blends of linear protonated polystyrene (PSH) and crosslinked deuterated polystyrene (PSD). Two series of samples were synthesized. In both cases the samples were made by dissolving the linear PSH in deuterated (d8) styrene monomer containing a small amount of divinyl benzene as a crosslinker which was then polymerized to form the PSD network around the linear PSH chains. The samples were all made at a concentration of 50/50 by weight PSD/PSH. A special effort was made to keep the samples single phase so that SANS could be used to study the thermodynamics of the system and compare with theory. This entailed working at relatively low crosslink densities (<1 mole % crosslink units). Series 1 is a set of samples with the same crosslink density varying the length of the linear chain. Series 2 is a set of samples containing the same length linear chain varying the crosslink density systematically. By extrapolating S(q) obtained from SANS to q=O the zero angle scattering, S(O), was obtained. S(O) is inversely proportional to the second derivative of the free energy with respect to composition, ∂2 (Δf/kT)/∂ø2. Assuming additivity of the free energies of mixing and elasticity, the portion of the zero angle scattering due to elasticity is calculated.

Small Angle Neutron Scattering Studies of Single Phase IPNs

1992 ◽  
Vol 274 ◽  
Author(s):  
Barry J. Bauer ◽  
Robert M. Briber ◽  
Shawn Malone ◽  
Claude Cohen
Keyword(s):  
Phase Separation ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Crosslink Density ◽  
Single Phase ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Miscible Polymer Blends ◽  
Low Levels

ABSTRACTInterpenetrating polymer networks (IPNs) have been synthesized from polymers that form miscible polymer blends. Full, semi-I and semi-II IPNs made from polystyrene-d8 and poly(vinylmethylether) can be made to phase separate by incorporating low levels of crosslinking. However, blends of these polymers have a negative Flory-Huggins interaction parameter, making them highly miscible. This indicates that formation of IPNs favors phase separation relative to blends.IPNs made from polystyrene-d8 and polystyrene-h8 show that increased crosslink density also destabilizes the mixture as shown by small angle neutron scattering.IPNs have also been made by crosslinking end functionalized polydimethylsiloxanes in the presence of nonfunctionalized, deuterated siloxanes. These IPNs are also destabilized by increasing crosslink density, suggesting that the destabilization is due to the network, and not to the particular type of network forming reaction.

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 KWS-1: Small-angle scattering diffractometer

2015 ◽  
Vol 1 ◽  
Author(s):  
Henrich Frielinghaus ◽  
Artem Feoktystov ◽  
Ida Berts ◽  
Gaetano Mangiapia
Keyword(s):  
High Resolution ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Small Angle Scattering ◽  
Angle Scattering

The KWS-1, which is operated by JCNS, Forschungszentrum Jülich, is a small-angle neutron scattering diffractometer dedicated to high resolution measurements.

Resolution functions of time-of-flight small-angle neutron scattering instruments with rectangular apertures

2007 ◽  
Vol 40 (1) ◽  
pp. 40-50 ◽  
Author(s):  
B. Grabcev
Keyword(s):  
Gravitational Field ◽  
Elastic Scattering ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Time Of Flight ◽  
Careful Analysis ◽  
Mathematical Relationship ◽  
Angle Scattering ◽  
Neutron Wavelength

Analytic forms are found for resolution functions of small-angle neutron scattering instruments. The expressions are developed as a function of momentum transfer (Q) rather than separately in terms of neutron wavelength (λ) and scattering angle (θ). Effects caused by the gravitational field as well as by quasi-elastic scattering are included. Explicit analytic forms for the transmission functions are proposed for both the incident and scattered beams, enabling careful analysis of any problem regarding small-angle scattering experiments. Due to the reciprocal mathematical relationship between λ, θ andQ, [λ, θ] space is employed to approach different aspects of the topic. Applications to time-of-flight instruments with rectangular apertures, including the choice of the most convenient instrumental parameters, the analysis of smearing effects and the data reduction toQspace, are presented.

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.

scholarly journals Model Membranes and Their Interactions with Native and Artificial Lipoproteins

2020 ◽  
Author(s):  
◽  
Sarah Waldie
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Model Membranes ◽  
Neutron Reflectometry ◽  
Model Systems ◽  
High Density Lipoproteins ◽  
The West ◽  
Structural Characterisation ◽  
Angle Scattering

Atherosclerosis arises from build-up of plaque in the blood, can result in cardiovascular disease and is the largest killer in the west. Low- and high-density lipoproteins are involved in the disease development by depositing and removing lipids to and from artery walls. These processes are complex and not fully understood however, therefore determining the specific roles of the components involved is of fundamental importance in the treatment of the disease. The work presented in this thesis investigates the production of recombinant tailor-deuterated cholesterol, the structure of cholesterol-containing model membranes and interactions of both native and reconstituted lipoproteins with model membranes. Deuteration is commonly used in neutron scattering for biological samples to provide highly important contrast and the complexity of the native lipoproteins leads to the use of more simple model systems where the compositions can be altered and investigated systematically. A protocol was developed to produce matchout-deuterated cholesterol for use in neutron scattering studies, as cholesterol is a hugely important component in membranes. The verification of the matchpoint of cholesterol was determined by small-angle neutron scattering and the localisation of cholesterol in model membranes was determined through the use of neutron reflectometry. The interactions of the native and reconstituted lipoproteins with model membranes were also followed by neutron reflectometry, while the structural characterisation of the reconstituted lipoproteins was carried out by small-angle scattering.

A Method for Interpreting Small Angle Neutron Scattering Data from Quasi-Spherical Objects

1994 ◽  
Vol 376 ◽  
Author(s):  
T.M. Sabine ◽  
W.K. Bertram ◽  
L.P. Aldridge
Keyword(s):  
Neutron Scattering ◽  
Multiple Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Small Angle Scattering ◽  
Scattering Data ◽  
Type Function ◽  
Scattering Pattern ◽  
Angle Scattering

ABSTRACTSmall angle scattering data are traditionally interpreted in terms of scattering patterns at the Porod and the Guinier limits. It is difficult to fit the entire scattering pattern to account for scattering from spheres because Rayleigh's formula contains oscillatory terms which are smeared out in practice by perturbations in the sizes of the scattering agents.It is proposed that a Lorenztian type function be used instead of Rayleigh's function. By using this equation it is possible to fit the entire small angle scattering pattern and obtain the correct forms of the Guinier and Porod limits.The effects of correlation and multiple scattering are also explored.

scholarly journals Advanced Small-Angle Scattering Instrument Available in the Tokyo Area. Time-Of-Flight, Small-Angle Neutron Scattering Developed on the iMATERIA Diffractometer at the High Intensity Pulsed Neutron Source J-PARC

2020 ◽  
Vol 4 (4) ◽  
pp. 42
Author(s):  
Satoshi Koizumi ◽  
Yohei Noda ◽  
Tomoki Maeda ◽  
Takumi Inada ◽  
Satoru Ueda ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
High Intensity ◽  
Small Angle Neutron Scattering ◽  
Time Of Flight ◽  
Small Angle Scattering ◽  
Proton Accelerator ◽  
Static Structure Factor ◽  
Angle Scattering ◽  
Pulsed Neutron

A method of time-of-flight, small-angle neutron scattering (TOF-SANS) has been developed based on the iMATERIA powder diffractometer at BL20, of the Materials and Life Sciences Facility (MLF) at the high-intensity proton accelerator (J-PARC). A large-area detector for SANS, which is composed of triple-layered 3He tube detectors, has a hole at its center in order to release a direct beam behind and to detect ultra-small-angle scattering. As a result, the pulsed-neutron TOF method enables us to perform multiscale observations covering 0.003 < q (Å−1) < 40 (qmax/qmix = 1.3 × 104) and to determine the static structure factor S(q) and/or form factor P(q) under real-time and in-situ conditions. Our challenge, using unique sample accessories of a super-conducting magnet and polarized neutron, is dynamic nuclear polarization (DNP) for contrast variation, especially for industrial use. To reinforce conventional SANS measurements with powder materials, grazing-incidence small-angle neutron scattering (GISANS) or reflectivity is also available on the iMATERIA instrument.

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