High-Temperature XRD Analysis of Polymers

1990 ◽  
Vol 34 ◽  
pp. 459-463
Author(s):  
Robert W. Green
Keyword(s):  
High Temperature ◽  
Temperature Control ◽  
Polymeric Materials ◽  
Xrd Analysis ◽  
Sample Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Temperature Xrd ◽  
Insight Into

High-temperature x-ray diffraction has many applications. Applied to polymeric materials it is a useful tool for investigating changes in crystallinity, providing insight into molding and extrusion problems, and for examining solvent-resistancy problems. An example of the increasing crystailine character of a polymer as a function of temperature can be seen in figure 1. Diffraction scans at 25°C, 100°C, 150°C, and 200°C clearly show the increasing crystalline character of the potymer with an increase in temperature. Control of sample temperature for a polymer is very important, when analyzing under air, because a momentary overshoot in temperature may lead to the sample igniting. High-temperature investigations of polymers are also subject to the problem of the sample warping and bowing.

Synthesis, crystal structure, and luminescence properties of a new microporous europium silicate: Na3EuSi6O15·1.47H2O

RSC Advances ◽  
2015 ◽  
Vol 5 (37) ◽  
pp. 29121-29125 ◽  
Author(s):  
Wei Liu ◽  
Ying Ji ◽  
Fuyang Liu ◽  
Min Yang ◽  
Ying Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Single Crystal ◽  
Xrd Analysis ◽  
Luminescence Properties ◽  
X Ray Diffraction ◽  
X Ray

A new microporous europium silicate, Na3EuSi6O15·1.47H2O (denoted as 1), was synthesized under high-temperature and high-pressure conditions, and structurally characterized by single-crystal and powder X-ray diffraction (XRD) analysis.

scholarly journals Monitoring of FES2 reactions using high-temperature XRD coupled with gas chromatography

2019 ◽  
Vol 34 (2) ◽  
pp. 90-96
Author(s):  
K.-A. M. Stirrup ◽  
M. A. Rodriguez ◽  
E. N. Coker ◽  
J. J. M. Griego ◽  
T. M. Anderson
Keyword(s):  
Gas Chromatography ◽  
High Temperature ◽  
Simultaneous Thermal Analysis ◽  
Gas Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Iron Disulfide ◽  
Thermal Batteries ◽  
High Temperature Xrd

High-temperature X-ray diffraction with concurrent gas chromatography (GC) was employed in the study of iron disulfide (FeS2) cathode pellets disassembled from thermal batteries. When FeS2 cathode materials were analyzed in an air environment, reaction of the KCl and LiCl salt phases led to the formation of Li2(SO4) and KFe2S3 phases beginning at ~230 °C. These phases subsequently reacted to generate various forms of potassium iron sulfates in the 280–500 °C range, with the final products resulting in a β-Fe2O3 phase and K2(SO4). Independent simultaneous thermal analysis coupled with mass spectroscopy (MS) augmented the diffraction results and supported the overall picture of FeS2 decomposition. Both gas analysis measurements (i.e. GC and MS) from the independent experiments confirmed the formation of SO2 off-gas species during the breakdown of the FeS2. In contrast, characterization of the same cathode material under inert conditions showed the persistence of the initial FeS2 phase throughout the entire temperature range of analysis.

On the Formation of Nanograined LiCo2O3(OH) Spinel-Type Material Synthesized via Modified Low-Temperature Sol-Gel Approach

2015 ◽  
Vol 1119 ◽  
pp. 106-110
Author(s):  
Rinlee Butch M. Cervera ◽  
Shu Yamaguchi
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Spinel Structure ◽  
Sol Gel ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Spinel Type ◽  
Selected Area Electron Diffraction ◽  
High Temperature Xrd ◽  
Average Grain Size

A new lithium cobalt oxyhydroxide compound has been successfully synthesized. This new compound has been found to be related to the low temperature LiCoO2 (LT-LiCoO2) spinel structure formed at low processing temperatures. With the use of a modified sol-gel approach, this compound with the composition of LiCo2O3(OH) can be successfully synthesized at around 150 °C. Structural analyses using powder X-ray diffraction (XRD) and selected area electron diffraction (SAED) suggest a cubic-spinel structure, which is also supported by FT-IR and TG/DTA analyses. In addition, from the TEM morphological analysis, a very fine nanograined LiCo2O3(OH) powder with an average grain size of 5 nm has been obtained. From these results, the presence of OH or water at low processing temperatures promotes a favorable formation of this structure. At higher temperatures (>400 °C), the phase transforms to a layered high-temperature LiCoO2 (HT-LiCoO2) structure with the excess cobalt precipitated as Co3O4 as suggested by the in-situ high temperature XRD analysis.

Coprecipitation Synthesis and Negative Thermal Expansion of R2Mo3O12 (R = Y, Yb)

2009 ◽  
Vol 79-82 ◽  
pp. 1567-1570 ◽  
Author(s):  
Hai Tao Yang ◽  
Wei Lin Lin ◽  
Fu Liang Shang ◽  
Yuan Hui Huang ◽  
Ling Gao
Keyword(s):  
Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Xrd Analysis ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
High Temperature Xrd ◽  
Coprecipitation Synthesis ◽  
Expansion Coefficients

In this research, powders of Y2Mo3O12 and Yb2Mo3O12 were successfully synthesized by liquid phase coprecipitation, followed with a heat treatment at 750°C for 6h. X-ray diffraction (XRD) analysis indicated that the Y2Mo3O12 and Yb2Mo3O12 were single orthorhombic structure with the space group of Pbcn. Negative thermal expansion properties of Y2Mo3O12 and Yb2Mo3O12 were studied with high temperature XRD analysis. The thermal expansion coefficients of Y2Mo3O12 and Yb2Mo3O12 were calculated to be -5.943×10-6K-1 and -6.237×10-6K-1 respectively.

Rhombohedral-cubic phase transition characterization of (Pb,Ge)Te using high-temperature XRD

2008 ◽  
Vol 23 (2) ◽  
pp. 137-140 ◽  
Author(s):  
J. Sariel ◽  
I. Dahan ◽  
Y. Gelbstein
Keyword(s):  
High Temperature ◽  
Cylindrical Specimen ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Continuous Transformation ◽  
X Ray ◽  
High Temperature Xrd ◽  
Powder Samples ◽  
Powder Metallurgy Approach

Rhombohedral-cubic transformation in Bi2Te3 doped-Pb1−xGexTe alloys is presented. Samples of Bi2Te3 doped Pb1−xGexTe were prepared by powder metallurgy approach. These powder samples were examined by high-temperature X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive spectroscopy. A bulk (pressed powder) cylindrical specimen was used for dilatometery characterizations. According to the XRD examinations it seems that upon increasing the temperatures a continuous transformation occurs from the rhombohedral to the cubic phase, accompanied by the formation of a small amount of the phase Ge0.74Pb3.26Te4.

A Low-High Temperature Camera for In-Situ X-Ray Diffraction Studies of Catalysts

1983 ◽  
Vol 27 ◽  
pp. 285-291
Author(s):  
J. Pielaszek ◽  
J.B. Cohen
Keyword(s):  
High Temperature ◽  
Porous Silica ◽  
X Ray Diffraction ◽  
X Ray ◽  
Controlled Atmospheres ◽  
Research Areas ◽  
High Temperature Xrd ◽  
Different Temperatures ◽  
Porous Silica Glass

X-Ray diffraction studies of substances under controlled atmospheres and at different temperatures are of great importance in many research areas. This is especially true in the area of catalysis, where the correlation of structural and catalytic properties is needed. The camera described here was made for this purpose although any sample in the powdered form can be studied as well. Many catalysts are in the form of highly dispersed metal deposited on a granulated support. The content of metal may vary from a few tenths to several percent. In a camera used by Janko and Borodzinski a small amount of catalyst was spread out on a porous silica glass sample holder which then was placed in a high temperature XRD camera with flowing gas of controlled composition.

The Influence of the Hydrothermal Temperature on the Morphologies of β-Ni(OH)2 Nanospheres and Nanoflakes

2012 ◽  
Vol 159 ◽  
pp. 376-379 ◽  
Author(s):  
Xiao Ming Fu
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Scanning Electron Microscope ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Low Reaction Temperature ◽  
Scanning Electron

β-Ni(OH)2 nanospheres and nanoflakes have been successfully synthesized with nickel nitrate as nickel source and stronger ammonia water as precipitant via the hydrothermal method. The phase and the morphologies of the samples have been characterized and analyzed by XRD (X-ray diffraction) and SEM (Scanning electron microscope), respectively. XRD analysis shows that the phase of the samples is β-Ni(OH)2. SEM analysis confirms that the low reaction temperature is propitious to the synthesis of β-Ni(OH)2 nanospheres. However, The high temperature is in favor of the synthesis of β-Ni(OH)2 nanosflakes.

Thermal Expansion Behaviour of Inconel-690 by In Situ High Temperature X-Ray Diffraction

2015 ◽  
Vol 830-831 ◽  
pp. 367-370 ◽  
Author(s):  
D. Ramachandran ◽  
A.M. Kamalan Kirubaharan ◽  
Arul Maximus Rabel ◽  
P. Kuppusami
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Thermal Exposure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Thermal Stability ◽  
Temperature Range ◽  
High Temperature Xrd ◽  
Inconel 690 ◽  
The Stability

Ni-Cr-Fe based alloy Inconel 690 is widely used in power plant, marine, chemical and nuclear applications due to its excellent mechanical properties, resistance to thermal creep deformation, good thermal stability and resistance to corrosive and oxidizing environments. In order to study the microstructure of the alloy and the precipitates formation during thermal exposure, the alloy was subjected to in-situ high temperature X-ray diffraction technique (HT-XRD) in the temperature range 298-1273K. Results of high temperature XRD patterns show (111), (200), (220) and (311) reflections confirming the stability of fcc structure in the temperature of investigation. With increase in the temperature, a shift in peak positions towards lower 2θ values due to lattice expansion was noticed. The average thermal expansion coefficient (TEC) of the alloy increased from 1.33 x 10-5 K-1 to 1.53 x 10-5 K-1 in the temperature range 298-1273 K. Scanning electron microscopy indicates austenitic grains of sizes in the range 100-150μm and chromium carbide precipitate at grain boundaries after the HT-XRD heat treatment.

In Situ Simultaneous Observation of Phase Transition and Electrical Properties of Pb(Zr,Ti)O3 Thin Film by High Temperature XRD and Electrical Measurement Apparatus

2006 ◽  
Vol 320 ◽  
pp. 53-56 ◽  
Author(s):  
Toru Onoue ◽  
Naoki Wakiya ◽  
Koichi Seo ◽  
Takanori Kiguchi ◽  
Nobuyasu Mizutani ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transition ◽  
High Temperature ◽  
Electrical Measurement ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Temperature Xrd ◽  
Phase Transition Temperatures

Pb(Zr0.05Ti0.95)O3/(La,Sr)CoO3 thin films were prepared by pulsed laser deposition (PLD) on SrTiO3(001) substrates. Phase transition behavior of Pb(Zr0.05Ti0.95)O3 (PZT) was investigated using high temperature X-ray diffraction (HT-XRD) and high-temperature electrical measurement. The phase transition temperature of PZT thin film is larger than bulk one. In 100 and 200nm-thickness epitaxial PZT thin films, the phase transition temperatures obtained from X-ray diffraction measurement and electrical property measurement are in good agreement.

Identification of acid-insoluble filter-plugging compounds and optimal acid-washing procedures for tubular backpulse pressure filters

TAPPI Journal ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 17-23
Author(s):  
KEVIN TAYLOR ◽  
RICH ADDERLY ◽  
GAVIN BAXTER
Keyword(s):  
Calcium Sulfate ◽  
Membrane Filter ◽  
Sulfamic Acid ◽  
Xrd Analysis ◽  
Metal Sulfides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gypsum Formation ◽  
Acid Washing ◽  
Hydrolysis Of

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.

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