scholarly journals Synthesis of New Metallized Polyimide Films with High Optical and Physical Performances

2016 ◽  
Vol 6 (1) ◽  
pp. 57 ◽  
Author(s):  
Saule Kudaikulova ◽  
Galina Boiko ◽  
Bulat Zhubanov ◽  
Oleg Prikhodko ◽  
Vanda Yu. Voytekunas ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Elevated Temperatures ◽  
Amic Acid ◽  
Surface Resistivity ◽  
Visible Range ◽  
X Ray Diffraction ◽  
Polyimide Films ◽  
X Ray ◽  
Physical Performances

Electroconductive and reflective metallized polyimide films have been prepared by heterogeneous chemical modification of polyimide surface. By carrying out the chemical reactions in situ in the modified layers of polyimide surface, a metal phase strongly impregnated into the polyimide surface is obtained. The steps of chemical modification have been studied on the model compound – poly(amic acid) on the basis of isophthaloylchloride and methylenedianthranilic acid which forms insoluble sodium or potassium poly(amicacid) salts (polyamate). Metallization of Kapton HN &amp; JP (from DuPont) and Upilex S (from Ube) films<br />has been carried out and the films have been characterized by X-ray diffraction (XRD), X-ray fine diffraction (XRFD), measurements of reflectivity in the visible range and surface resistivity at elevated temperatures. It is shown that reflectivity coefficients of silvered films are 90-92% and surface resistivity is about 0.5 Ω/sq.

scholarly journals New Reflectable Materials on the Basis of Polyimides

2016 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
Saule K. Kudaikulova
Keyword(s):  
Chemical Modification ◽  
Chemical Reactions ◽  
Model Compound ◽  
Elevated Temperatures ◽  
Amic Acid ◽  
Surface Resistivity ◽  
Visible Range ◽  
Polyimide Films ◽  
Heterogeneous Chemical

Electroconductive and reflective metallized polyimide films have been prepared by heterogeneous chemical modification of polyimide surface. By carrying out the chemical reactions <em>in situ</em> in the modified layers of polyimide surface, thereby a metal phase strongly impregnated into the polyimide surface is obtained. The steps of chemical modification have been studied on the model compound – poly(amic acid) on the basis of pyromellite dianhydride and oxydianiline, which forms insoluble sodium or potassium poly(amicacid) salts (polyamate). Metallization of Kapton HN &amp; JP (from DuPont) and Upilex S films have been carried out and the films have been characterized by XRD, XRFD, and measurements of reflectivity in the visible range and surface resistivity at elevated temperatures. It is shown that reflectivity coefficients of silvered films are 90-92% and surface resistivity is about 0.5 Ω.

Transformation of ferrihydrite to hematite: anin situinvestigation on the kinetics and mechanisms

2008 ◽  
Vol 72 (1) ◽  
pp. 217-220 ◽  
Author(s):  
H. P. Vu ◽  
S. Shaw ◽  
L. G. Benning
Keyword(s):  
High Resolution ◽  
Growth Mechanism ◽  
Elevated Temperatures ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Time Resolved ◽  
X Ray ◽  
Resolution Electron ◽  
Stage Process

AbstractThe kinetics and mechanisms of the transformation of 2-line ferrihydrite (FH) to hematite (HM), in the presence of Pb at elevated temperatures and high pH condition, were elucidated using synchrotron-based,in situenergy dispersive X-ray diffraction (EDXRD). The time-resolved diffraction data indicated that HM crystallization occurred via a two-stage process. Based on the EDXRD data, combined with high-resolution electron microscopic images, an aqueous-aided 2D growth mechanism is proposed for both HM crystallization stages.

In Situ High-Energy X-Ray Diffraction Studies of Melting, Solidification and Solid-State Transformation of Ni3Sn

MRS Advances ◽  
2020 ◽  
Vol 5 (29-30) ◽  
pp. 1529-1535 ◽  
Author(s):  
Rijie Zhao ◽  
Jianrong Gao ◽  
Yang Ren
Keyword(s):  
Solid State ◽  
Elevated Temperatures ◽  
High Energy ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
State Transformation ◽  
Solid State Transformation ◽  
X Ray ◽  
Melting And Solidification

AbstractMelting, solidification and solid-state transformation of the intermetallic Ni3Sn compound were investigated in situ using synchrotron high-energy X-ray diffraction. It was observed that the compound undergoes a hexagonal to cubic transition before melting. In solidification, a disordered cubic phase crystallizes from the liquid at a large undercooling but it is reordered prior to bulk solidification. In melting and solidification, forced or natural flows are active bringing about significant changes of crystal orientations. These in situ observations provided insights into phase transformations of Ni3Sn at elevated temperatures and their roles in formation of metastable microstructure consisting of coarse grains and subgrains.

Investigation of the self-discharge behaviors of the LiMn2O4 cathode at elevated temperatures: in situ X-ray diffraction analysis and a co-doping mitigation strategy

2019 ◽  
Vol 7 (21) ◽  
pp. 13364-13371 ◽  
Author(s):  
Xiaoyu Tang ◽  
Jie Zhou ◽  
Miao Bai ◽  
Weiwei Wu ◽  
Shaowen Li ◽  
...  
Keyword(s):  
Diffraction Analysis ◽  
Elevated Temperatures ◽  
Lithium Ion ◽  
Mitigation Strategy ◽  
The Self ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Limn2o4 Cathode

The lithium ion re-intercalated into the LiMn2O4 lattice during self-discharge.

A simple gas introduction system for cryogenic powder X-ray diffraction

2021 ◽  
Vol 54 (4) ◽  
Author(s):  
Robert Hodyss ◽  
Tuan H. Vu ◽  
Mathieu Choukroun ◽  
Morgan L. Cable
Keyword(s):  
Elevated Temperatures ◽  
Simple System ◽  
Cryogenic Temperatures ◽  
X Ray Diffraction ◽  
Volatile Organics ◽  
X Ray

A simple system is described for the introduction of gases into standard X-ray diffraction capillaries mounted in situ in the X-ray beam of laboratory X-ray diffraction instruments. This system retains many of the advantages of the standard Norby cell, but does not require custom machining and has less stringent space restrictions. The system has been used to study the crystallization and interaction of volatile organics at cryogenic temperatures, but gas–solid interactions could also be studied at elevated temperatures using this approach.

Effects of NaBH4 Additions on Hydrogen Absorption by Nanostructured FeTi Powders

2008 ◽  
Vol 587-588 ◽  
pp. 921-925 ◽  
Author(s):  
Sofia F. Marques ◽  
Raquel A. Silva ◽  
Jose Brito Correia ◽  
Nobumitsu Shohoji ◽  
Carmen M. Rangel
Keyword(s):  
Hydrogen Absorption ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Low Cost ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gas Atmosphere ◽  
Scanning Electron

FeTi intermetallic powders are very promising media for reversible hydrogen storage. However, difficult activation treatments including annealing at elevated temperatures in high pressure H2 gas atmosphere are mandatory. In the present work nanostructured FeTi powders were produced and activated in situ at room temperature using mechanical alloying/milling (MA/MM) of pure metallic constituents, Fe and Ti, added with sodium borohydride. The resultant powders, FeTiHx, already H2 pre-charged, absorbed a significant amount of H2 but require optimization for reversible absorption/desorption. This system has one of the highest volumetric storage capacities and can be produced at low cost. Several parameters of the as-milled powders were controlled. The phase constitution of the reaction products was characterized by X-ray diffraction and scanning electron microscopy and the absorption isotherms of the activated powders were determined.

Preparation and characterization of a copper@polyimide core–shell structure via an in situ induction/imidization route

2016 ◽  
Vol 29 (5) ◽  
pp. 569-574
Author(s):  
Haoran Zhou ◽  
Dexin Wang ◽  
Chunyan Qu ◽  
Changwei Liu ◽  
Shanshan Mao
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Amic Acid ◽  
Core Shell ◽  
Oxidation Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Pure Cu

Based on the combination of an in situ induction and imidization method for improving the interface bonding of an inorganic material and a polymer, copper@polyimide (Cu@PI) core–shell composite particles have been successfully prepared from poly(amic acid) ammonium salts (PAAS) and a Cu complex via a simple solvothermal process. The structures and the morphologies of the samples were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy (TEM), respectively. It was found that PAAS formed PI via a thermal imidization and subsequently precipitated in the solvent. Through crystallization induction, it then successfully coated on the surface of the formed Cu particles. Based on thermo gravimetric analyses curves and due to no Cu oxidation reactions taking place in the core coated with high-temperature-resistant PI, the weight increase was determined to be 106.4%, instead of up to 124.0% in samples consisting of pure Cu.

scholarly journals The Transformation Mechanism of β Phase to ω-Related Phases in Nb-Rich γ-TiAl Alloys Studied by In Situ High-Energy X-Ray Diffraction

2013 ◽  
Vol 772 ◽  
pp. 85-89 ◽  
Author(s):  
Andreas Stark ◽  
Michael Oehring ◽  
Florian Pyczak ◽  
Thomas Lippmann ◽  
Lars Lottermoser ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
High Energy ◽  
X Ray Diffraction ◽  
Transformation Mechanism ◽  
Quenching Rate ◽  
Repeated Heating ◽  
X Ray ◽  
Β Phase ◽  
Diffusion Controlled

In recent years intermetallic γ-TiAl based alloys with additional amounts of the ternary bcc β Ti(Al,Nb) phase attracted increasing attention due to their improved workability at elevated temperatures. Depending on alloy composition and heat treatment the ductile high-temperature β phase can transform to several ordered phases at lower temperatures. However, currently available phase diagrams of these multiphase alloys are quite uncertain and the precipitation kinetics of some metastable phases is far from understood. In the present study various transformation pathways of the third phase were observed in situ by means of high-energy X-ray diffraction using synchrotron radiation. A Ti-45Al-10Nb (at.%) specimen was subjected to a temperature ramp of repeated heating cycles (700 °C - 1100 °C) with subsequent quenching at different rates. Depending on the quenching rate reversible transformations of the B2-ordered βo phase to different ω-related phases were observed. The results indicate that the complete transformation from βo to hexagonal B82-ordered ωo consists of two steps which are both diffusion controlled but proceed with different velocities.

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