Examining marine particulate organic matter at sub-micron scales using scanning transmission X-ray microscopy and carbon X-ray absorption near edge structure spectroscopy

2004 ◽  
Vol 92 (1-4) ◽  
pp. 107-121 ◽  
Author(s):  
Jay A. Brandes ◽  
Cindy Lee ◽  
Stuart Wakeham ◽  
Michael Peterson ◽  
Chris Jacobsen ◽  
...  
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Edge Structure ◽  
X Ray ◽  
Scanning Transmission ◽  
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.

Investigation of Organic Matter Entrapped in Synthetic Carbonates—A Multimethod Approach

2012 ◽  
Vol 19 (1) ◽  
pp. 132-144 ◽  
Author(s):  
Emilie Chalmin ◽  
Yves Perrette ◽  
Bernard Fanget ◽  
Jean Susini
Keyword(s):  
Organic Matter ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Edge Structure ◽  
X Ray ◽  
Multimethod Approach ◽  
The Stability ◽  
Log Linear ◽  
X Ray Absorption ◽  
Surface Changes

AbstractOrganic matter (OM) entrapped in calcite is regularly used for environmental studies; however, insertion mechanisms and types of interaction remain poorly understood. The present study used a new methodology to investigate interactions between OM and the calcite matrix during crystallization processes with humic acid (HA) entrapment. A multimethod approach confirmed that HA is both adsorbed onto the calcite surface and incorporated into the calcite lattice during crystallization. Our results also confirm the log-linear correlation between fluorescence intensity and calcite matrix HA concentration. Fourier transform infrared spectroscopy showed that HA in colloidal conformation is adsorbed onto the calcite surface as a result of the structure of the OH stretching band. We also developed a new method based on synchrotron analysis that uses sulfur as a tracer element for entrapped HA and that localizes the OM electrostatically adsorbed onto the calcite surface. Changes in the sulfur environment, determined using X-ray absorption near-edge structure spectroscopy, indicated more complex insertion mechanisms than simple adsorption of HA during calcite crystallization. Desorption experiments revealed the stability of the OM atomic structure and its layered nature. These results allowed us to draw up a general model of OM insertion in calcite.

scholarly journals The Origin of Organic Matter in the Solar System: Evidence from the Interplanetary Dust Particles

2004 ◽  
Vol 213 ◽  
pp. 275-280 ◽  
Author(s):  
G. J. Flynn ◽  
L. P. Keller ◽  
C. Jacobsen ◽  
S. Wirick
Keyword(s):  
Organic Matter ◽  
Gas Phase ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Aqueous Processing ◽  
Interplanetary Dust Particles ◽  
Volatile Elements ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

Interplanetary dust particles (IDPs), ∼ 10μm particles from comets and asteroids, have been collected by NASA from the Earth's stratosphere. We compared carbon X-ray Absorption Near-Edge Structure (XANES) and Fourier Transform Infra-Red (FTIR) spectra of anhydrous and hydrated interplanetary dust particles and found that anhydrous and hydrated IDPs have similar types and abundances of organic carbon. This is different from results on meteorites, which show that hydrated carbonaceous meteorites contain abundant organic matter, while anhydrous carbonaceous meteorites contain less carbon mostly in elemental form. But all anhydrous carbonaceous meteorites are depleted in moderately volatile and volatile elements in a pattern that suggested they experienced temperatures in excess of 1200°C, a temperature sufficient to destroy any organic matter they originally contained, while many anhydrous IDPs show no evidence of severe heating. These IDP results indicate that the bulk of the pre-biotic organic matter in extraterrestrial materials formed before aqueous processing, possibly by irradiation of C-bearing ices or by a Fisher-Tropsch type process operating in the gas phase of the nebula or in the interstellar medium.

Origin of luminescence from ZnO/CdS core/shell nanowire arrays

Nanoscale ◽  
2014 ◽  
Vol 6 (16) ◽  
pp. 9783-9790 ◽  
Author(s):  
Zhiqiang Wang ◽  
Jian Wang ◽  
Tsun-Kong Sham ◽  
Shaoguang Yang
Keyword(s):  
Optical Properties ◽  
Chemical Imaging ◽  
Nanowire Arrays ◽  
Nano Composites ◽  
Core Shell ◽  
Edge Structure ◽  
X Ray ◽  
Optical Luminescence ◽  
Scanning Transmission ◽  
X Ray Absorption

Chemical imaging, electronic structure and optical properties of ZnO/CdS nano-composites have been investigated using scanning transmission X-ray microscopy (STXM), X-ray absorption near-edge structure (XANES) and X-ray excited optical luminescence (XEOL) spectroscopy.

Large-scale hollow nanoparticle identification by X-ray absorption spectroscopy

2017 ◽  
Vol 95 (11) ◽  
pp. 1151-1155
Author(s):  
Yuanhong Tang ◽  
Zhiqiang Wang ◽  
Dongniu Wang ◽  
Jian Wang ◽  
Tsun-Kong Sham
Keyword(s):  
Absorption Spectroscopy ◽  
Chemical Bonding ◽  
Large Scale ◽  
Sol Gel ◽  
Hollow Spheres ◽  
Hollow Nanoparticles ◽  
Edge Structure ◽  
X Ray ◽  
Scanning Transmission ◽  
X Ray Absorption

Large-scale SiO2 hollow nanoparticles were synthesized by a sol-gel method. The composition, morphology, and chemical bonding information of SiO2 hollow nanoparticles were studied by X-ray absorption near edge structure (XANES) and scanning transmission X-ray microscopy (STXM). XANES at the Si L-edge and K-edge reveal the characteristics of hollow nanoparticles, which are essentially amorphous SiO2 with a slightly longer Si–O bond than SiO2 nanoparticles on average and deficiencies in oxygen. Individual SiO2 hollow spheres were also examined using STXM, which provides spectromicroscopic information, as well as the absolute thickness, of the sample.

scholarly journals Organic matter in interplanetary dust particles

2008 ◽  
Vol 4 (S251) ◽  
pp. 267-276 ◽  
Author(s):  
G. J. Flynn ◽  
L. P. Keller ◽  
S. Wirick ◽  
C. Jacobsen
Keyword(s):  
Organic Matter ◽  
Infrared Spectroscopy ◽  
Thermal Processing ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Radiation Processing ◽  
Interplanetary Dust Particles ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

AbstractAnhydrous interplanetary dust particles (IDPs), which are the most mineralogically primitive extraterrestrial materials available for laboratory analysis, contain several percent organic matter. The high O:C and N:C ratios suggest the organic matter in the anhydrous IDPs is significantly less altered by thermal processing than the organic matter in meteorites. X-ray Absorption Near-Edge Structure (XANES) spectroscopy and infrared spectroscopy demonstrate the presence of C=C, most likely as C-rings, C=O, and aliphatic C-H2and C-H3in all the IDPs examined. A D-rich spot, containing material that is believed to have formed in a cold molecular cloud, has C-XANES and infrared spectra very similar to the organic matter in the anhydrous IDPs, possibly indicating a common formation mechanism. However the primitive organic matter in the IDPs differs from the interstellar/circumstellar organic matter characterized by astronomical infrared spectroscopy in the relative strengths of the asymmetric aliphatic C-H2and C-H3absorptions, with the IDP organic having a longer mean chain length. If both types of organic matter originated by the same process, this may indicate the interstellar organic matter has experienced more severe radiation processing than the organic matter in the primitive IDPs.

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