scholarly journals Diffuse reflectance infrared spectra of the Meade Peak phosphatic shale member of the permian Phosphoria formation, Caribou County, Idaho

2004 ◽  
Author(s):  
Robert J. Horton
Keyword(s):  
Infrared Spectra ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Infrared ◽  
Phosphoria Formation

Diffuse reflectance infrared spectra of kaolinite and kaolinite/alkali halide mixtures. Curve-fitting of the OH stretching region

1991 ◽  
Vol 69 (11) ◽  
pp. 1786-1790 ◽  
Author(s):  
K. H. Michaelian ◽  
W. I. Friesen ◽  
S. Yariv ◽  
A. Nasser
Keyword(s):  
Infrared Spectra ◽  
Curve Fitting ◽  
Alkali Halide ◽  
Diffuse Reflectance ◽  
Alkali Halides ◽  
Hydroxyl Groups ◽  
Caesium Chloride ◽  
Inner Surface ◽  
Structural Hydroxyl ◽  
Diffuse Reflectance Infrared

Diffuse reflectance infrared spectra of kaolinite and binary mixtures of this clay with alkali halides have been analysed using curve-fitting and deconvolution. For caesium chloride and caesium bromide, decomposition of the hydroxyl stretching region has made it possible to correlate the positions and intensities of bands due to structural hydroxyl groups of kaolinite, or to intercalated water, with the degree of intercalation. One of these bands, arising from uncoupled inner surface OH stretching in kaolinite, is not identifiable in spectra of the uncomplexed clay or mixtures where intercalation did not occur. A new band revealed by curve-fitting spectra of intercalated samples is attributed either to water at the interface between the clay and the alkali halide, or to an FeO—H impurity in the kaolinite. Key words: kaolinite, infrared, curve-fitting.

Effect of absorbing matrixes on diffuse reflectance infrared spectra

1986 ◽  
Vol 58 (11) ◽  
pp. 2179-2184 ◽  
Author(s):  
Paul J. Brimmer ◽  
Peter R. Griffiths
Keyword(s):  
Infrared Spectra ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Infrared

Pre-treatment of diffuse reflectance infrared spectra for quantitative analysis of macro porous polymer particles

1999 ◽  
Vol 20 (1) ◽  
pp. 47-57 ◽  
Author(s):  
Yi-Zeng Liang ◽  
Alfred A Christy ◽  
Anne K Nyhus ◽  
Steinar Hagen ◽  
Jon-Sverre Schanche ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Infrared Spectra ◽  
Diffuse Reflectance ◽  
Porous Polymer ◽  
Polymer Particles ◽  
Pre Treatment ◽  
Diffuse Reflectance Infrared

Angular Dependence of Diffuse Reflectance Infrared Spectra. Part III: Linearity of Kubelka-Munk Plots

1988 ◽  
Vol 42 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Paul J. Brimmer ◽  
Peter R. Griffiths
Keyword(s):  
Angular Dependence ◽  
Infrared Spectra ◽  
Diffuse Reflectance ◽  
Strong Absorption ◽  
Absorption Bands ◽  
Linear Region ◽  
Line Configuration ◽  
Munk Function ◽  
Before And After ◽  
Diffuse Reflectance Infrared

The linearity of plots of the Kubelka-Munk function against concentration is investigated for weak and strong absorption bands in the spectrum of a typical organic analyte, caffeine. The linear region is extended when measurements are made with an off-axis optical geometry, in comparison to an in-line configuration. For the latter configuration, the linearity is improved when crossed polarizers are placed before and after the sample.

Angular Dependence of Diffuse Reflectance Infrared Spectra. Part II: Effect of Polarization

1987 ◽  
Vol 41 (5) ◽  
pp. 791-797 ◽  
Author(s):  
Paul J. Brimmer ◽  
Peter R. Griffiths
Keyword(s):  
Angular Dependence ◽  
Infrared Spectra ◽  
Diffuse Reflectance ◽  
Absolute Intensity ◽  
Absorption Bands ◽  
Reflectance Measurement ◽  
Wire Grid ◽  
Optical Geometry ◽  
Ft Ir ◽  
Diffuse Reflectance Infrared

The magnitude of specular and diffuse Fresnel reflectance from powdered samples was investigated with the use of an FT-IR spectrogoniophotometer with wire-grid polarizers mounted in front of and behind the sample. Specular Fresnel reflectance maintains the polarization of the incoming infrared beam and can therefore be eliminated by crossing the orientation of the second polarizer relative to the first. For neat samples, diffuse Fresnel reflectance was found to be only slightly affected by the presence of the two polarizers. While specular Fresnel reflectance is affected by the optical geometry used in making the reflectance measurement, diffuse Fresnel reflectance is unaffected by optical geometry and can only be eliminated by dilution of the neat sample. For dilute samples, the optical geometry and the orientation of the two polarizers slightly affect the absolute intensity of absorption bands, but do not change relative band intensities or band positions.

Diffuse Reflectance Infrared Spectra of 4-Nitrobenzoic Acid and 4-Cyanobenzoic Acid Self-Assembled on Fine Silver Particles

1998 ◽  
Vol 52 (8) ◽  
pp. 1047-1052 ◽  
Author(s):  
Hyouk Soo Han ◽  
Chang Hwan Kim ◽  
Kwan Kim
Keyword(s):  
Infrared Spectra ◽  
Diffuse Reflectance ◽  
Infrared Light ◽  
Particle Sizes ◽  
Metal Powders ◽  
Silver Particles ◽  
Silver Surface ◽  
Silver Films ◽  
Nitrobenzoic Acid ◽  
Diffuse Reflectance Infrared

Adsorption of 4-nitrobenzoic acid and 4-cyanobenzoic acid on fine silver powders was investigated by diffuse reflectance infrared Fourier transform spectroscopy. It was concluded that both molecules were adsorbed on the surfaces of silver powders as carboxylate, after deprotonation, assuming a perpendicular orientation with respect to the silver surface. In a comparison with the reflection-absorption infrared spectra taken for the same molecules on vacuum-evaporated thick silver films, the usual surface selection rule that applied to flat metal surfaces also seemed applicable to the surface of fine metal particles, as long as the diameter of the particles was near 2 μm. Metal powders with diameters greater than 5μm appeared inappropriate as an adsorbent, however, probably because of particle sizes quite close to the wavelength of the infrared light used.

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