Kinetics of the gas-phase halogenation of a polyethylene surface as studied with x-ray photoelectron spectroscopy

1990 ◽  
Vol 23 (17) ◽  
pp. 3922-3928 ◽  
Author(s):  
James F. Elman ◽  
Louis J. Gerenser ◽  
Kim E. Goppert-Berarducci ◽  
John M. Pochan
Keyword(s):  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Kinetics Of ◽  
Polyethylene Surface

Kinetic and structural studies of oxygen availability of the mixed oxides Pr1–xMxOy (M = Ce, Zr)

1996 ◽  
Vol 11 (8) ◽  
pp. 1960-1971 ◽  
Author(s):  
M. Yu. Sinev ◽  
G. W. Graham ◽  
L. P. Haack ◽  
M. Shelef
Keyword(s):  
Gas Phase ◽  
Mixed Oxide ◽  
Photoelectron Spectroscopy ◽  
Mixed Oxides ◽  
Structural Features ◽  
Redox Processes ◽  
Structural Studies ◽  
X Ray ◽  
Speed Up ◽  
Kinetics Of

One composition of Pr–Ce mixed oxide and a range of compositions of Pr–Zr mixed oxide were prepared by coprecipitation methods and characterized by x-ray powder diffraction, thermogravimetric analysis, and x-ray photoelectron spectroscopy. Based on phases formed, the PrOy—ZrO2 system in an oxygen-containing atmosphere at moderate temperatures (up to 800–1000 °C) is analogous to that of CeO2–ZrO2. Addition of either Ce or Zr to pure Pr oxide affects both the total amount of oxygen that can be reversibly exchanged between oxide and gas phase and the kinetics of the redox processes. Ce dramatically increases the amount (per Pr atom) and lowers the temperature of exchange, Zr slightly decreases the amount and also lowers the temperature of exchange, and both modifiers speed up the rate. These observations are rationalized in terms of bulk and surface structural features of the mixed oxides.

GROWTH OF OXIDE LAYER ON GERMANIUM (011) SUBSTRATE UNDER DRY AND WET ATMOSPHERES

1999 ◽  
Vol 06 (06) ◽  
pp. 1053-1060 ◽  
Author(s):  
N. TABET ◽  
J. AL-SADAH ◽  
M. SALIM
Keyword(s):  
Simple Model ◽  
Oxide Film ◽  
Growth Kinetics ◽  
Photoelectron Spectroscopy ◽  
Early Stage ◽  
X Ray ◽  
Apparent Thickness ◽  
Different Temperatures ◽  
Kinetics Of

X-ray Photoelectron Spectroscopy (XPS) has been used to investigate the oxidation of (011) Ge substrates. The sample surfaces were CP4-etched, then annealed in situ, at different temperatures, for various durations. Dry and wet atmospheres were used. The oxidation rate during the early stage was increased by the presence of moisture in the atmosphere. A simple model was used to define and determine an apparent thickness of the oxide film from XPS measurements. The time dependence of the apparent thickness is consistent with a partial coverage of the surface by oxide islands. The growth kinetics of the oxide islands obeys a nearly cubic law.

Gas‐phase x‐ray photoelectron spectroscopy of model molecules relating to the thermochromism in poly(3‐alkylthiophene)

1990 ◽  
Vol 93 (9) ◽  
pp. 6357-6362 ◽  
Author(s):  
M. P. Keane ◽  
S. Svensson ◽  
A. Naves de Brito ◽  
N. Correia ◽  
S. Lunell ◽  
...  
Keyword(s):  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
X Ray

scholarly journals Enhanced removal of hexavalent chromium by different acid-modified biochar derived from corn straw: behavior and mechanism

2020 ◽  
Vol 81 (10) ◽  
pp. 2270-2280
Author(s):  
Yonggang Xu ◽  
Tianxia Bai ◽  
Yubo Yan ◽  
Yunfeng Zhao ◽  
Ling Yuan ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hydrogen Ion ◽  
Corn Straw ◽  
Order Model ◽  
Freundlich Model ◽  
X Ray ◽  
Modified Biochar ◽  
Before And After ◽  
Pseudo Second Order ◽  
Kinetics Of

Abstract It is of great significance to remove Cr(VI) from water as a result of its high toxicity. Biochar from corn straw was modified by different acids (HNO3, H2SO4 and H3PO4) to remove Cr(VI) from aqueous solution. To estimate the removal mechanisms of Cr(VI) by the acid-modified biochars, batch experiments were performed in the light of contact time, Cr(VI) concentration, and pH, and the characteristics of acid-modified biochars before and after Cr(VI) adsorption were investigated by Fourier transform infrared spectra (FTIR) and X-ray photoelectron spectroscopy (XPS). The adsorption kinetics of Cr(VI) by acid-modified biochars were consistent with the pseudo-second-order model, and the adsorption isotherm obeyed the Freundlich model. Furthermore, the acid- modified biochars could supply more oxygen-containing functional groups (-COOH and -OH) as electron donor (e−) and hydrogen ion (H+) to enhance the reduction of Cr(VI) to Cr(III), resulting in enhanced removal of Cr(VI). HNO3-modified biochar exhibited the highest removal efficiency of Cr(VI). In general, the acid modifition of biochar was an effective method to increase the removal of Cr(VI).

X-Ray photoelectron spectroscopy of monosubstituted perfluorobenzenes

1977 ◽  
Vol 55 (8) ◽  
pp. 1279-1284 ◽  
Author(s):  
Barry C. Trudell ◽  
S. James W. Price
Keyword(s):  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Binding Energies ◽  
Photoelectron Spectra ◽  
Atomic Charges ◽  
X Ray ◽  
Sophisticated Analysis ◽  
Charge Calculations

The gas phase X-ray photoelectron spectra, XPS, were observed for the series C6F5X (X = F, Cl, I, Br, H). Binding energies were determined from the spectra using the ESCAPLOT Program. Charge calculations were carried out using Equalization of Electronegativity, CNDO/2, and ACHARGE approaches on each molecule. The more sophisticated analysis leads to the following equation correlating the (C 1s) binding energies and the atomic charges qi[Formula: see text]

X-ray photoelectron spectroscopy study of the growth kinetics of biomimetically grown hydroxyapatite thin-film coatings

2010 ◽  
Vol 256 (23) ◽  
pp. 7178-7185 ◽  
Author(s):  
K. McLeod ◽  
S. Kumar ◽  
N.K. Dutta ◽  
R.St.C. Smart ◽  
N.H. Voelcker ◽  
...  
Keyword(s):  
Thin Film ◽  
Growth Kinetics ◽  
Photoelectron Spectroscopy ◽  
Spectroscopy Study ◽  
X Ray ◽  
Film Coatings ◽  
Thin Film Coatings ◽  
Kinetics Of

XPS AND XPD ANALYSIS OF NITROGEN ADSORPTION ON THE Ti(0001) SURFACE

1997 ◽  
Vol 04 (06) ◽  
pp. 1309-1314 ◽  
Author(s):  
D. P. FRICKEL ◽  
M. V. KUZNETSOV ◽  
E. V. SHALAEVA
Keyword(s):  
Photoelectron Spectroscopy ◽  
Titanium Surface ◽  
Nitrogen Adsorption ◽  
Text Structure ◽  
X Ray ◽  
Photoelectron Diffraction ◽  
The Third ◽  
Adsorption Temperature ◽  
Nearest Neighborhood ◽  
Kinetics Of

X-ray photoelectron spectroscopy (XPS) and X-ray photoelectron diffraction (XPD) were used to examine the kinetics of nitrogen adsorption on the Ti(0001) surface at temperatures from 220 to 570 K and adsorption exposures from 0 to 1000 L. At the adsorption temperature T=300 K two chemically nonequivalent states of nitrogen were found: NI (1×1 lattice) localized in octapores between the first and second titanium monolayers and NII (presumably [Formula: see text] structure) on the titanium surface. The third nitrogen state, N0 , which is also localized on the surface but has unoccupied octapores in the nearest neighborhood, is observed with a decrease in the adsorption temperature to 220 K. A model of nitrogen interaction with the Ti(0001) surface in vacuum was proposed proceeding from the temperature dependence of the kinetic adsorption curves.

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