Tracer diffusion of four arm polystyrene star molecules into linear and star polymer matrices from nuclear reaction analysis

2003 ◽  
Vol 13 (11) ◽  
pp. 2765-2770 ◽  
Author(s):  
F. Roger Colley ◽  
Stephen A. Collins ◽  
Randal W. Richards
Keyword(s):  
Nuclear Reaction ◽  
Tracer Diffusion ◽  
Polymer Matrices ◽  
Star Polymer ◽  
Nuclear Reaction Analysis ◽  
Star Molecules

High-temperature diffusion of oxygen in synthetic diopside measured by nuclear reaction analysis

1999 ◽  
Vol 63 (5) ◽  
pp. 673-686 ◽  
Author(s):  
L. Pacaud ◽  
J. Ingrin ◽  
O. Jaoul
Keyword(s):  
High Temperature ◽  
Nuclear Reaction ◽  
Diffusion Coefficients ◽  
Tracer Diffusion ◽  
Nuclear Reaction Analysis ◽  
Gas Mixture ◽  
Diffusion Study ◽  
Self Diffusion ◽  
Temperature Diffusion ◽  
Diffusion Profiles

AbstractWe have performed O self-diffusion experiments in synthetic diopside single crystals along the b-axis at temperatures ranging from 1473–1643 K, under controlled O partial pressure (10−11–10−2 atm). The 18O tracer diffusion was imposed by solid/gas exchange between 16O in diopside and 18O2-enriched argon-hydrogen-H2O gas mixture. Diffusion profiles of 18O were measured by Nuclear Reaction Analysis 18O (p,α) 15N. The diffusion coefficients are described by , with log D0(m2/s)=−9.2 ± 1.0 and E 310 ± 30 kJ/mol.Our results are in agreement with Ryerson and McKeegan's (1994) data and Farver's (1989) data along a direction perpendicular to the c direction. Experiments performed in a wide pO2 range show that D is independent of pO2.We observe no change in the diffusion regime up to 1643 K (i.e. 22 K prior to melting temperature). This result differs from the diffusion study of Ca in diopside by Dimanov and Ingrin (1995), where a strong enhancement of Ca mobility, attributed to an excess disorder in the Ca-sublattice, was observed above 1523 K. We conclude that O diffusion in diopside is not affected by this premelting phenomenon.

Tracer diffusion of deuterated polystyrene into polystyrene–poly(α-methyl styrene) studied by nuclear reaction analysis

Polymer ◽  
1998 ◽  
Vol 39 (16) ◽  
pp. 3623-3629 ◽  
Author(s):  
M.G.D. van der Grinten ◽  
A.S. Clough ◽  
T.E. Shearmur ◽  
M. Geoghegan ◽  
R.A.L. Jones
Keyword(s):  
Nuclear Reaction ◽  
Tracer Diffusion ◽  
Nuclear Reaction Analysis ◽  
Methyl Styrene

Hydrogen release from irradiated elastomers measured by Nuclear Reaction Analysis

2016 ◽  
Vol 371 ◽  
pp. 216-219 ◽  
Author(s):  
J. Jagielski ◽  
U. Ostaszewska ◽  
D.M. Bielinski ◽  
D. Grambole ◽  
M. Romaniec ◽  
...  
Keyword(s):  
Nuclear Reaction ◽  
Hydrogen Release ◽  
Nuclear Reaction Analysis

scholarly journals PEG-POSS Star Molecules Blended in Polyurethane with Flexible Hard Segments: Morphology and Dynamics

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 99
Author(s):  
Konstantinos N. Raftopoulos ◽  
Edyta Hebda ◽  
Anna Grzybowska ◽  
Panagiotis A. Klonos ◽  
Apostolos Kyritsis ◽  
...  
Keyword(s):  
Glass Transition ◽  
Star Polymer ◽  
Polymerization Process ◽  
Degree Of Crystallinity ◽  
Dielectric Relaxation Spectroscopy ◽  
Scanning Calorimetry ◽  
Similar System ◽  
Soft Phase ◽  
Hard Segments ◽  
Star Molecules

A star polymer with a polyhedral oligomeric silsesquioxanne (POSS) core and poly(ethylene glycol) (PEG) vertex groups is incorporated in a polyurethane with flexible hard segments in-situ during the polymerization process. The blends are studied in terms of morphology, molecular dynamics, and charge mobility. The methods utilized for this purpose are scanning electron and atomic force microscopies (SEM, AFM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and to a larger extent dielectric relaxation spectroscopy (DRS). It is found that POSS reduces the degree of crystallinity of the hard segments. Contrary to what was observed in a similar system with POSS pendent along the main chain, soft phase calorimetric glass transition temperature drops as a result of plasticization, and homogenization of the soft phase by the star molecules. The dynamic glass transition though, remains practically unaffected, and a hypothesis is formed to resolve the discrepancy, based on the assumption of different thermal and dielectric responses of slow and fast modes of the system. A relaxation α′, slower than the bulky segmental α and common in polyurethanes, appears here too. A detailed analysis of dielectric spectra provides some evidence that this relaxation has cooperative character. An additional relaxation g, which is not commonly observed, accompanies the Maxwell Wagner Sillars interfacial polarization process, and has dynamics similar to it. POSS is found to introduce conductivity and possibly alter its mechanism. The study points out that different architectures of incorporation of POSS in polyurethane affect its physical properties by different mechanisms.

Symmetries of 13C tracer deposition in EAST D and He plasmas investigated on the sub-mm to 100 mm scale by deuteron nuclear reaction analysis

2021 ◽  
Vol 166 ◽  
pp. 112292
Author(s):  
S. Möller ◽  
R. Ding ◽  
H. Xie ◽  
B.F. Gao ◽  
B.G. Wang ◽  
...  
Keyword(s):  
Nuclear Reaction ◽  
Nuclear Reaction Analysis ◽  
13C Tracer

Stopping-powers and straggling of 15N ions for nuclear reaction analysis at 6.385 MeV

1996 ◽  
Vol 118 (1-4) ◽  
pp. 7-10 ◽  
Author(s):  
P. Goppelt-Langer ◽  
S. Yamamoto ◽  
Y. Aoki ◽  
H. Takeshita ◽  
H. Naramoto
Keyword(s):  
Nuclear Reaction ◽  
Nuclear Reaction Analysis

scholarly journals In-Situ Ion Beam Measurements of Deuterium Loading in Thin Foil Electrochemical Cells

1989 ◽  
Vol 157 ◽  
Author(s):  
J.A. Knapp ◽  
T.R. Guilinger ◽  
M.J. Kelly ◽  
D. Walsh ◽  
B.L. Doyle
Keyword(s):  
Nuclear Reaction ◽  
Ion Beam ◽  
Cold Fusion ◽  
Thin Foil ◽  
Nuclear Reaction Analysis ◽  
Deuterium Content ◽  
Electrochemical Cells ◽  
External Beam

ABSTRACTA key element of recent assertions of "cold fusion" has been the claim that electrochemical loading of deuterium into Pd electrodes can produce D:Pd levels exceeding 1:1. Using external beam nuclear reaction analysis of Pd foil electrodes in operating electrochemical cells, we have directly monitored deuterium content in-situ. No conditions were found which resulted in loadings higher than ∼0.9.

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