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Title: Distinguishing physical mechanisms using GISAXS experiments and linear theory: the importance of high wavenumbers

Authors:
ORCiD logo; ; ; ; ORCiD logo;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1409539
Report Number(s):
BNL-114591-2017-JA¿¿¿
Journal ID: ISSN 2045-2322
DOE Contract Number:
SC0012704
Resource Type:
Journal Article
Resource Relation:
Journal Name: Scientific Reports; Journal Volume: 7; Journal Issue: 1
Country of Publication:
United States
Language:
English

Citation Formats

Norris, Scott A., Perkinson, Joy C., Mokhtarzadeh, Mahsa, Anzenberg, Eitan, Aziz, Michael J., and Ludwig, Karl F.. Distinguishing physical mechanisms using GISAXS experiments and linear theory: the importance of high wavenumbers. United States: N. p., 2017. Web. doi:10.1038/s41598-017-01059-x.
Norris, Scott A., Perkinson, Joy C., Mokhtarzadeh, Mahsa, Anzenberg, Eitan, Aziz, Michael J., & Ludwig, Karl F.. Distinguishing physical mechanisms using GISAXS experiments and linear theory: the importance of high wavenumbers. United States. doi:10.1038/s41598-017-01059-x.
Norris, Scott A., Perkinson, Joy C., Mokhtarzadeh, Mahsa, Anzenberg, Eitan, Aziz, Michael J., and Ludwig, Karl F.. 2017. "Distinguishing physical mechanisms using GISAXS experiments and linear theory: the importance of high wavenumbers". United States. doi:10.1038/s41598-017-01059-x.
@article{osti_1409539,
title = {Distinguishing physical mechanisms using GISAXS experiments and linear theory: the importance of high wavenumbers},
author = {Norris, Scott A. and Perkinson, Joy C. and Mokhtarzadeh, Mahsa and Anzenberg, Eitan and Aziz, Michael J. and Ludwig, Karl F.},
abstractNote = {},
doi = {10.1038/s41598-017-01059-x},
journal = {Scientific Reports},
number = 1,
volume = 7,
place = {United States},
year = 2017,
month = 5
}
  • If small angle X-ray scattering (SAXS) utilizing the soft X-ray region is available, advanced and unique experiments, which differ from traditional SAXS methods, can be realized. For example, grazing-incidence small angle X-ray scattering (GISAXS) using hard X-ray is a powerful tool for understanding the nanostructure in both vertical and lateral directions of thin films, while GISAXS utilizing the tender X-ray region (SX-GISAXS) enables depth-resolved analysis as well as a standard GISAXS analysis in thin films. Thus, at BL-15A2 at the Photon Factory, a dedicated diffractometer for SX-GISAXS (above 2.1 keV) was constructed. This diffractometer is composed of four vacuum chambers andmore » can be converted into the vacuum state from the sample chamber in front of the detector surface. Diffractions are clearly observed until 12th peak when measuring collagen by SAXS with an X-ray energy of 2.40 keV and a camera length of 825 mm. Additionally, we conducted the model experiment using SX-GISAXS with an X-ray energy of 2.40 keV to confirm that a poly(methyl methacrylate)-poly(n-butyl acrylate) block copolymer thin film has a microphase-separated structure in the thin film, which is composed of lamellae aligned both parallel and perpendicular to the substrate surface. Similarly, in a polystyrene-poly(methyl methacrylate) block copolymer thin film, SX-GISAXS with 3.60 keV and 5.73 keV revealed that hexagonally packed cylinders are aligned parallel to the substrate surface. The incident angle dependence of the first order peak position of the q{sub z} direction obtained from experiments at various incident X-ray energies agrees very well with the theoretical one calculated from the distorted wave Born approximation.« less
  • Understanding and controlling bond-breaking sequences of oxygenates on transition metal catalysts can greatly impact the utilization of biomass feedstocks for fuels and chemicals. The decomposition of ethylene glycol, as the simplest representative of biomass-derived polyols, was studied via density functional theory (DFT) calculations to identify the differences in reaction pathways between Pt and the more active Ni/Pt bimetallic catalyst. Comparison of the computed transition states indicated three potentially feasible paths from ethylene glycol to C1 oxygenated adsorbates on Pt. While not important on Pt, the pathway to 1,2-dioxyethylene (OCH₂CH₂O) is favored energetically on the Ni/Pt catalyst. Temperature-programmed desorption (TPD) experimentsmore » were conducted with deuterated ethylene glycols for comparison with DFT results. These experiments confirmed that decomposition of ethylene glycol on Pt proceeds via initial O–H bond cleavage, followed by C–H and the second O–H bond cleavages, whereas on the Ni/Pt surface, both O–H bonds are cleaved initially. The results are consistent with vibrational spectra and indicate that tuning of the catalyst surface can selectively control bond breaking. Finally, the significant mechanistic differences in decomposition of polyols compared to that of monoalcohols and hydrocarbons serve to identify general trends in bond scission sequences.« less
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