Characterization of chitin preparations using powder and film X-ray diffraction methods

2013 ◽  
Vol 28 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Jeffrey R. Deschamps
Keyword(s):  
Diffraction Pattern ◽  
Purification Procedure ◽  
Limited Extent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
Natural Polysaccharide ◽  
Different Sources

Chitin is a natural polysaccharide found in many diverse phyla and almost always occurs in association with protein. In this study the chitin polymer is characterized by X-ray diffraction from its naturally occurring unprocessed state through various steps used in the purification procedure. In addition, the effect of different treatments on the final product is examined. These studies show that native chitin has a characteristic diffraction pattern that is not altered by the mild treatments used to isolate relatively pure chitin. Chitins prepared from different sources exhibit the same characteristic diffraction pattern. In addition, chitin films prepared using non-degrading solvents retain most of the characteristic patterns. De-acylation of chitin to produce chitosan results in large changes to the diffraction pattern. To a very limited extent features present in the diffraction pattern of native chitin can be recovered by re-acylation of chitosan.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Characterization of Mycelium-Like Material Formed During Drying of Salt Stock Prunes

1994 ◽  
Vol 57 (9) ◽  
pp. 817-819
Author(s):  
ROBIN Y.-Y. CHIOU ◽  
WEN-CHING TZENG ◽  
KUO-FONG HUANG
Keyword(s):  
Organic Matter ◽  
Sodium Chloride ◽  
Citric Acid ◽  
Diffraction Analysis ◽  
Diffraction Pattern ◽  
X Ray Diffraction ◽  
X Ray

Material with the appearance of mold mycelium was formed on salt stock prunes during drying. The moisture-free mycelium-like material consisted of 98.5 to 98.7% sodium chloride (NaCl), 1.67% organic matter and 0.165% acidity expressed as citric acid. X-ray diffraction analysis of the material revealed a diffraction pattern similar to that of NaCl. Formation of the material was dependent upon the efficiency and extent of drying. However, the material was not observed on deskinned salt stock prunes subjected to drying.

Structural Characterization of Nickel(II) Tetraphenylporphyrin

1996 ◽  
Vol 49 (12) ◽  
pp. 1273 ◽  
Author(s):  
AL Maclean ◽  
GJ Foran ◽  
BJ Kennedy ◽  
P Turner ◽  
TW Hambley
Keyword(s):  
Synchrotron Radiation ◽  
Single Crystal ◽  
Bond Length ◽  
Diffraction Pattern ◽  
Structural Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths ◽  
Single Crystal Analysis

The structure of 5,10,15,20-tetraphenylporphinatonickel(II) ([Ni( tpp )]) has been studied by both X-ray diffraction (powder and single-crystal methods) and EXAFS. The bond lengths obtained from analysis of the EXAFS agree, within standard deviations, with those obtained from the X-ray diffraction studies. The Ni-N bond length of 1.93(1) Ǻ agrees especially well with the value of 1.931(2) Ǻ obtained from the single-crystal analysis. The powder X-ray diffraction pattern, collected by using synchrotron radiation, is presented.

scholarly journals Water-Driven Structural Transformation in Cobalt Trimesate Metal-Organic Frameworks

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4751
Author(s):  
Jayashree Ethiraj ◽  
Vinayagam Surya ◽  
Parasuraman Selvam ◽  
Jenny G. Vitillo
Keyword(s):  
Diffraction Pattern ◽  
Diffuse Reflectance ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Metal Organic ◽  
Divalent Cobalt

We report on the synthesis and the characterization of a novel cobalt trimesate metal-organic framework, designated as KCL-102. Powder X-ray diffraction pattern of KCL-102 is dominated by a reflection at 10.2° (d-spacing = 8.7 Å), while diffuse reflectance UV-Vis spectroscopy indicates that the divalent cobalt centers are in two different coordination geometries: tetrahedral and octahedral. Further, the material shows low stability in humid air, and it transforms into the well-known phase of hydrous cobalt trimesate, Co3(BTC)2·12H2O. We associated this transition with the conversion of the tetrahedral cobalt to octahedral cobalt.

scholarly journals Physicochemical Characterization of Moroccan Phosphate and Coke of a Solid Combustible

2016 ◽  
Vol 8 (2) ◽  
pp. 72 ◽  
Author(s):  
Ikbal Bouatba ◽  
Mbarek Benchanaa ◽  
Mustapha El Hammioui ◽  
Latifa Bilali
Keyword(s):  
Porous Structure ◽  
Diffraction Pattern ◽  
Physicochemical Characterization ◽  
Total Pore Volume ◽  
Physicochemical Characteristics ◽  
Morphological Observation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phosphate Ore

<p>This paper concerns the study of the phosphate ore and a coke of solid combustible. The determination of their physicochemical characteristics and the study of their structural, textural and morphological aspects before and after thermal treatment are important and necessary for understanding of the reaction mechanisms and of the modelling of the processes of combustion and calcination.</p><p>The characterization of these materials was accomplished according to various experimental techniques such as: X-ray diffraction; infrared spectroscopy, scanning electron microscopy, porosimetry and the BET method. The results obtained show that the X-ray diffraction pattern of the coke presents only the crystalline phase of the graphite. The diffraction pattern of the raw phosphate as well as the crystallographic parameters at 25°C <br /> (a = 9.36 Å, c = 6.90 Å) are consistent with those given in the literature and indeed correspond to those of the crystal lattice of pure fluorapatite. The specific surface of natural phosphate is in the range of 13.36 m².g<sup>-1</sup> and that of the coke is 0.361 m².g<sup>-1</sup>. The total pore volume of the phosphate ore measured by the condensation of nitrogen adsorbed was 0.178 mL and the mean opening diameter of the pores is 0.029 m. The real density of the phosphate (2.96 g.cm<sup>-3</sup>) and that of the coke (1.36 g.cm<sup>-3</sup>), were determined using an ultra pycnometer. Morphological observation of the grain surface shows fairly homogenous areas and a porous structure in the phosphate ore. The coke grains show on the contrary a difference in the grain size and a non-porous structure.</p>

A tool for X-ray diffraction analysis of thin layers on substrates: substrate peak removal method

2000 ◽  
Vol 33 (1) ◽  
pp. 108-111
Author(s):  
J.-D. Kamminga ◽  
R. Delhez ◽  
Th. H. de Keijser ◽  
E. J. Mittemeijer
Keyword(s):  
Thin Layer ◽  
Diffraction Analysis ◽  
Diffraction Pattern ◽  
Tool Steel ◽  
Steel Substrate ◽  
Thin Layers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Separate Measurement

A method is proposed that removes the substrate peaks from a diffraction pattern recorded from a substrate covered with a thin layer, using a separate measurement of the uncovered substrate. The obtained diffractogram without substrate peaks can then be used for the characterization of the microstructure of the thin layer. As an example, the method is shown to yield good results for a TiN layer deposited on a tool-steel substrate.

Preparation and characterization of NH4Bi3F10

1992 ◽  
Vol 7 (9) ◽  
pp. 2511-2513 ◽  
Author(s):  
D. Niznansky ◽  
J.L. Rehspringer
Keyword(s):  
Ir Spectra ◽  
Diffraction Pattern ◽  
Related Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Different Temperatures

A new NH4Bi3F10 compound was prepared, which results from a reaction between Bi2O3 and NH4F in an argon stationary atmosphere. It has a cubic fluorite-related structure isotypic with KBi3F10 with space group Fm3m (a = 11.974 Å). Further heating leads to decomposition to BiF3. IR spectra at different temperatures show the disappearance of NH4 group characteristic vibrations. Indexed x-ray diffraction pattern and IR spectra at different decomposition temperatures are given.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Sign in / Sign up

Export Citation Format

Share Document