Metal Atom Reactions with Polymer Films

1986 ◽  
Vol 72 ◽  
Author(s):  
Caroline A. Kovac ◽  
Jean L. Jordan ◽  
Roger A. Pollak
Keyword(s):  
Synchrotron Radiation ◽  
Metal Atom ◽  
Chemical Nature ◽  
Photoemission Spectroscopy ◽  
Carbonyl Groups ◽  
Complex Chemical ◽  
X Ray ◽  
Metal Atoms ◽  
Metal Atom Reactions ◽  
X Ray Absorption

AbstractThe chemical nature of the interface formed when an electropositive metal (chromium) is evaporated on the surface of oxygen-containing polymers has been investigated by synchrotron-radiation excited photoemission spectroscopy and by near-edge X-ray absorption fine stnrcture spectroscopy (NEXAFS). PMDA-ODA polyimide was studied along with two polymers intended to more simply model the complex chemical functionality of polyimide. Core-level spectra were resolved into distinct peaks, which were assigned to specific atoms in the polymer units, and changes in the spectra were monitored as chromium metal atoms were evaporated onto the surface. Similarly, NEXAFS spectra were taken as a function of chromium deposition. Results of these experiments show that chromium initially reacts very rapidly with surface carbonyl groups, but less strongly with ether oxygens or arene rings. In all polymers studied, formation of an electron-rich, carbide-like species was observed.

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.

Machine Learning Powered by Principal Component Descriptors as the Key for Sorted Structural Fit of XANES

2021 ◽  
Author(s):  
Andrea Martini ◽  
Alexander A. Guda ◽  
Sergey A. Guda ◽  
Aram L. Bugaev ◽  
Olga V. Safonova ◽  
...  
Keyword(s):  
Machine Learning ◽  
Structural Analysis ◽  
Synchrotron Radiation ◽  
Free Electron Laser ◽  
Principal Component ◽  
Analytical Tool ◽  
X Ray ◽  
Radiation Sources ◽  
X Ray Absorption

Modern synchrotron radiation sources and free electron laser made X-ray absorption spectroscopy (XAS) an analytical tool for the structural analysis of materials under in situ or operando conditions. Fourier approach...

X-Ray Absorption Spectra of Uranium by Synchrotron Radiation

1981 ◽  
Vol 20 (8) ◽  
pp. L612-L614 ◽  
Author(s):  
Hirohiko Adachi ◽  
Kazumi Fujima ◽  
Kazuo Taniguchi ◽  
Chie Miyake ◽  
Shosuke Imoto
Keyword(s):  
Synchrotron Radiation ◽  
Absorption Spectra ◽  
X Ray ◽  
X Ray Absorption

scholarly journals X-Ray Absorption Studies of Ti/Polymer and Cr/Polymer Interfaces

1993 ◽  
Vol 304 ◽  
Author(s):  
R. L. Opila ◽  
K. Konstadinidis ◽  
A. O. Ibidunni ◽  
A. J. Davenport ◽  
H. S. Isaacs
Keyword(s):  
Absorption Spectroscopy ◽  
Polymer Surfaces ◽  
Polymer Interfaces ◽  
Final Reaction Product ◽  
X Ray ◽  
Metal Atoms ◽  
Absorption Studies ◽  
In Situ Heating ◽  
X Ray Absorption

AbstractThe interface formed between metals, Ti and Cr, and polymers, epoxy and triazine, have been studied, nondestructively, using x-ray absorption spectroscopy. The metals were sputtered onto the polymer surfaces. Titanium reacts extensively, up to Ti thicknesses of 100 Å while Cr remains primarily metallic. In situ heating at 200°C increases the extent of reaction for both metals. Heating has a greater effect on metal/epoxy interfaces than metal/triazine. Titanium and Cr were ion implanted into the polymer in order to determine the interactions of isolated metal atoms with the polymer. Titanium and Cr appear to form oxides as the final reaction product, and the Ti is tetrahedrally coordinated.

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