Monitoring Thermal Oxidation of Sulfur Crosslinks in SBR-Elastomers by Quantitative Analysis of Sulfur K-Edge XANES-Spectra

2001 ◽  
Vol 74 (2) ◽  
pp. 281-294 ◽  
Author(s):  
H. Modrow ◽  
J. Hormes ◽  
F. Visel ◽  
R. Zimmer
Keyword(s):  
Quantitative Analysis ◽  
Quantitative Description ◽  
Edge Structure ◽  
X Ray ◽  
Oxidative Aging ◽  
Vulcanized Rubber ◽  
Sample Composition ◽  
Aging Resistance ◽  
Oxidative Processes ◽  
X Ray Absorption

Abstract This paper presents a quantitative description of the processes occurring at the sulfur crosslinks of vulcanized rubber during thermo-oxidative aging. To extract this information in a nondestructive way, sulfur K-edge X-ray absorption near-edge structure (XANES) spectra have been analyzed quantitatively. We find that reversion takes place before the onset of oxidative processes at the sulfur bridges. Parallel to the oxidative processes, the production of cyclic sulfanes takes place. Both the relative and absolute contributions of the different reactions involving the sulfur crosslinks vary strongly with sample composition. Whereas antidegradants delay the thermo-oxidative aging without actually changing the aging resistance of the sulfur bonds, both the amount of S8/TBBS (N-tert-butylbenzothiazole-2-sulfenamide) and the presence of carbon black in the sample enhance this parameter considerably.

Investigation of Sulfur Crosslinking Interfacial of Natural Rubber (NR) Blending with Carboxyalted Styrene Butadiene Rubber (XSBR) Using X-Ray Absorption Spectroscopy

2015 ◽  
Vol 1087 ◽  
pp. 131-136
Author(s):  
Chanaphan Lamlong ◽  
Wirach Taweepreda ◽  
Rattapong Nu-Mard ◽  
Prayoon Songsiriritthigul
Keyword(s):  
Natural Rubber ◽  
Crosslinking Density ◽  
Styrene Butadiene Rubber ◽  
Local Geometry ◽  
Butadiene Rubber ◽  
Edge Structure ◽  
X Ray ◽  
Oxidative Processes ◽  
Styrene Butadiene ◽  
X Ray Absorption

The sulfur crosslinking films from Natural Rubber (NR), Carboxylated Stryrene Butadiene Rubber (XSBR) latices, and their blends have been investigated using X-ray absorption near-edge structure spectroscopy (XANES). The film was prepared by casting the latex compound on glass surface and heating at 120oC in a hot air oven for 10 minutes. The sulfur crosslinking density were studied by the XANES. This was done to provide the local geometry and electronic environment of sulfur bonding in the rubber networks. We found that the reversion takes place before the onset of oxidative processes at the sulfur bridges. Parallel to the oxidative processes, the production of cyclic sulfanes takes places. This relationship depends on the rubber compositions.

Discrepancy in the quantitative oxidation-state analysis of Eu species in sulfide phosphors by K-, L1- and L3-edge XANES spectrometry: choice of absorption edge and measurement mode

2018 ◽  
Vol 33 (4) ◽  
pp. 585-592 ◽  
Author(s):  
Takashi Yamamoto ◽  
Akira Yukumoto
Keyword(s):  
Quantitative Analysis ◽  
Oxidation State ◽  
Absorption Edge ◽  
Oxidation States ◽  
Xanes Spectroscopy ◽  
Edge Structure ◽  
X Ray ◽  
Measurement Mode ◽  
Constituent Elements ◽  
X Ray Absorption

A quantitative analysis of the oxidation state of europium (Eu) in phosphor samples was performed using X-ray absorption near-edge structure (XANES) spectroscopy to investigate the influence of the constituent elements, absorption edge and measurement mode on the evaluated oxidation states.

Quantitative Analysis of Deconvolved X-ray Absorption Near-Edge Structure Spectra: A Tool To Push the Limits of the X-ray Absorption Spectroscopy Technique

2014 ◽  
Vol 53 (18) ◽  
pp. 9778-9784 ◽  
Author(s):  
Paola D’Angelo ◽  
Valentina Migliorati ◽  
Ingmar Persson ◽  
Giordano Mancini ◽  
Stefano Della Longa
Keyword(s):  
Quantitative Analysis ◽  
Absorption Spectroscopy ◽  
Spectroscopy Technique ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

Chemical and orientational imaging of polymeric samples

1994 ◽  
Vol 52 ◽  
pp. 68-69
Author(s):  
H. Ade ◽  
B. Hsiao ◽  
G. Mitchell ◽  
E. Rightor ◽  
A. P. Smith ◽  
...  
Keyword(s):  
Ethylene Terephthalate ◽  
National Laboratory ◽  
Brookhaven National Laboratory ◽  
Carbonyl Groups ◽  
Aromatic Rings ◽  
Edge Structure ◽  
X Ray ◽  
Scanning Transmission ◽  
Polymeric Samples ◽  
X Ray Absorption

We have used the Scanning Transmission X-ray Microscope at beamline X1A (X1-STXM) at Brookhaven National Laboratory (BNL) to acquire high resolution, chemical and orientation sensitive images of polymeric samples as well as point spectra from 0.1 μm areas. This sensitivity is achieved by exploiting the X-ray Absorption Near Edge Structure (XANES) of the carbon K edge. One of the most illustrative example of the chemical sensitivity achievable is provided by images of a polycarbonate/pol(ethylene terephthalate) (70/30 PC/PET) blend. Contrast reversal at high overall contrast is observed between images acquired at 285.36 and 285.69 eV (Fig. 1). Contrast in these images is achieved by exploring subtle differences between resonances associated with the π bonds (sp hybridization) of the aromatic groups of each polymer. PET has a split peak associated with these aromatic groups, due to the proximity of its carbonyl groups to its aromatic rings, whereas PC has only a single peak.

Full-Field Calcium K-Edge X-ray Absorption Near-Edge Structure Spectroscopy on Cortical Bone at the Micron-Scale: Polarization Effects Reveal Mineral Orientation

2016 ◽  
Vol 88 (7) ◽  
pp. 3826-3835 ◽  
Author(s):  
Bernhard Hesse ◽  
Murielle Salome ◽  
Hiram Castillo-Michel ◽  
Marine Cotte ◽  
Barbara Fayard ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Edge Structure ◽  
Full Field ◽  
Polarization Effects ◽  
X Ray ◽  
X Ray Absorption

scholarly journals Database of ab initio L-edge X-ray absorption near edge structure

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yiming Chen ◽  
Chi Chen ◽  
Chen Zheng ◽  
Shyam Dwaraknath ◽  
Matthew K. Horton ◽  
...  
Keyword(s):  
High Throughput ◽  
Scattering Theory ◽  
Research Community ◽  
Metal Compounds ◽  
Edge Structure ◽  
X Ray ◽  
Initial Release ◽  
Computational Workflow ◽  
X Ray Absorption

AbstractThe L-edge X-ray Absorption Near Edge Structure (XANES) is widely used in the characterization of transition metal compounds. Here, we report the development of a database of computed L-edge XANES using the multiple scattering theory-based FEFF9 code. The initial release of the database contains more than 140,000 L-edge spectra for more than 22,000 structures generated using a high-throughput computational workflow. The data is disseminated through the Materials Project and addresses a critical need for L-edge XANES spectra among the research community.

Theoretical and experimental investigation of point defects in cubic boron nitride

MRS Advances ◽  
2017 ◽  
Vol 2 (29) ◽  
pp. 1545-1550 ◽  
Author(s):  
Nicholas L. McDougall ◽  
Jim G. Partridge ◽  
Desmond W. M. Lau ◽  
Philipp Reineck ◽  
Brant C. Gibson ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Optical Emission ◽  
Wide Band ◽  
Wide Band Gap ◽  
Edge Structure ◽  
X Ray ◽  
Substitutional Defects ◽  
X Ray Absorption ◽  
Annealing Experiments

ABSTRACTCubic boron nitride (cBN) is a synthetic wide band gap material that has attracted attention due to its high thermal conductivity, optical transparency and optical emission. In this work, defects in cBN have been investigated using experimental and theoretical X-ray absorption near edge structure (XANES). Vacancy and O substitutional defects were considered, with O substituted at the N site (ON) to be the most energetically favorable. All defects produce unique signatures in either the B or N K-edges and can thus be identified using XANES. The calculations coupled with electron-irradiation / annealing experiments strongly suggest that ON is the dominant defect in irradiated cBN and remains after annealing. This defect is a likely source of optical emission in cBN.

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