SOME ADSORPTION PHENOMENA OF NITROANILINES ON ALKALINE EARTH COMPOUNDS

1966 ◽  
Vol 44 (24) ◽  
pp. 3051-3056 ◽  
Author(s):  
R. W. Frei ◽  
H. Zeitlin ◽  
G. Fujie
Keyword(s):  
Surface Area ◽  
Alkaline Earth ◽  
Diffuse Reflectance ◽  
Visible Region ◽  
Reflectance Spectroscopy ◽  
Reflectance Spectra ◽  
Electronic Polarization ◽  
Diffuse Reflectance Spectra ◽  
Polarization Theory ◽  
Adsorption Phenomena

The spectral behavior of o- and p-nitroanaline adsorbed on various alkaline earth compounds has been studied by reflectance spectroscopy. Regular bathochromic shifts in the diffuse reflectance spectra have been observed for the absorption maxima in the visible region in order of increasing size of the adsorbent cation. Progressive removal of coadsorbed moisture which competes for active adsorbent sites resulted in an enhancement of the bathochromic shifts. The intensity of the absorption maxima as measured by peak heights was found to be dependent upon the size of both cations and anions of the adsorbents. Interpretation of observed phenomena was advanced in terms of electronic polarization theory and varying surface area of the adsorbents.

Effect of Preparation Parameters on the Microporous Structure of Ni/SiO2 Catalysts

1996 ◽  
Vol 431 ◽  
Author(s):  
F. E. Castillon ◽  
N. Bodganchikova ◽  
S. Fuentes ◽  
M. Avalos
Keyword(s):  
Surface Area ◽  
Silicic Acid ◽  
Diffuse Reflectance ◽  
Nickel Nitrate ◽  
Reflectance Spectra ◽  
Microporous Structure ◽  
Hydrogenation Catalysts ◽  
Diffuse Reflectance Spectra ◽  
Group 2

AbstractIn this work we report the synthesis of Ni/SiO2 catalysts promoted by group 2 (IIA) cations (calcium and barium) which are currently used as hydrogenation catalysts. The effect of the preparation parameters aging, base agent, and type of cation, on the surface area of catalysts is evaluated. Catalysts were prepared by precipitation of the precursor silicic acid, along with nickel nitrate and calcium and barium carbonates, with NaOH, NH4OH and Na2CO3as precipitating agents. Catalysts were characterized by diffuse reflectance spectra (DRS) and by BETsurface area measurements. Results are discussed in terms of solgel chemistry (1).

Optical Spectra of Phenazine, 5,10-Dihydrophenazine, and the Phenazhydrins

1970 ◽  
Vol 24 (3) ◽  
pp. 339-343 ◽  
Author(s):  
G. A. Wheaton ◽  
L. J. Stoel ◽  
N. B. Stevens ◽  
C. W. Frank
Keyword(s):  
Optical Properties ◽  
Absorption Spectra ◽  
Diffuse Reflectance ◽  
Visible Region ◽  
Optical Spectra ◽  
Reflectance Spectra ◽  
Subtraction Technique ◽  
Uv Spectrum ◽  
Diffuse Reflectance Spectra ◽  
Related Compounds

The optical properties of phenazine, 5,10-dihydrophenazine, 1: 1 phenazhydrin, and 3: 1 phenazhydrin have been investigated, and ir, uv, and diffuse reflectance spectra are reported. The ir data indicate that the structures of the phenazhydrins resemble those of the parent compounds. The uv spectrum of 5,10-dihydrophenazine has a Λmax at 350 nm, which is not in agreement with a previously reported value of 325 nm. Absorption spectra of the reduced phenazine were also obtained via diffuse reflectance and a subtraction technique. Absorption in the visible region which is not present in the solution spectra is observed in the diffuse reflectance spectra of the phenazhydrins. The optical spectra of the four related compounds are collectively presented and discussed.

Examining the Diffuse Reflectance Spectra and the Radiation Stability for the Mixtures of BaSO4 Micropowders and SiO2 Nanopowders with Various Specific Surface Area

2019 ◽  
Vol 806 ◽  
pp. 106-112 ◽  
Author(s):  
Mikhail M. Mikhailov ◽  
Semyon A. Yuryev ◽  
Alexey N. Lapin
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Diffuse Reflectance ◽  
Radiation Stability ◽  
Reflectance Spectra ◽  
Subsequent Increase ◽  
Diffuse Reflectance Spectra ◽  
Reflectance Coefficient ◽  
Reflective Power

The paper is devoted to studying the effect of the specific surface area (SSA) of SiO2nanopowders (3 wt.%) added to BaSO4powders of a micron size on grain size distribution and diffuse reflectance spectra (ρλ) within the UV, visible, and near IR regions. Additionally, the authors have examined the spectra alteration (Δρλ) after irradiating with electrons (E=30 KeV). It has been established that mere mixing of the powders at a low concentration of nanoparticles leads to the post-irradiation decrease in the reflective power and to the subsequent increase in the reflectance coefficient stability.

Studies on the structures of cobalt pyridinaldoximates. I. The preparation and structural investigation of those complexes containing chlorine

1967 ◽  
Vol 20 (3) ◽  
pp. 429 ◽  
Author(s):  
MW Blackmore ◽  
RJ Magee
Keyword(s):  
Diffuse Reflectance ◽  
Structural Investigation ◽  
Reflectance Spectra ◽  
Diffuse Reflectance Spectra

The preparation of some new complexes of cobalt and 2-pyridinaldoxime are described. Magnetic and conductometric measurements are reported along with their infrared, ultraviolet and visible, and diffuse reflectance spectra. The possible structure of one of the complexes is postulated.

Infrared diffuse reflectance spectra of micropowders of Ni1–x Zn x Fe2O4 ferrites

2017 ◽  
Vol 59 (3) ◽  
pp. 543-549 ◽  
Author(s):  
Sh. N. Alieva ◽  
A. M. Kerimova ◽  
R. B. Abdullaev ◽  
T. R. Mekhtiev
Keyword(s):  
Diffuse Reflectance ◽  
Reflectance Spectra ◽  
Diffuse Reflectance Spectra
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