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.

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 In situ visualisation and analysis of dynamic single atom processes in heterogeneous catalysts

2021 ◽  
Author(s):  
Pratibha L. Gai ◽  
Edward D. Boyes
Keyword(s):  
Chemical Reactions ◽  
Heterogeneous Catalysts ◽  
Solid Surfaces ◽  
Single Atom ◽  
Vital Part ◽  
Heterogeneous Chemical ◽  
Operating Temperatures ◽  
Heterogeneous Chemical Reactions

Heterogeneous chemical reactions catalyzed over solid surfaces at operating temperatures are used to produce a vital part of energy, food, healthcare products, cleaner environments and chemicals.

Synthesis of Surface-Metallized Polyimide Films via in Situ Reduction of (Perfluoroalkanoato)silver(I) Complexes in a Poly(amic acid) Precursor

1998 ◽  
Vol 10 (5) ◽  
pp. 1408-1421 ◽  
Author(s):  
Robin E. Southward ◽  
Christopher M. Boggs ◽  
David W. Thompson ◽  
Anne K. St. Clair
Keyword(s):  
Amic Acid ◽  
In Situ Reduction ◽  
Polyimide Films ◽  
Acid Precursor

Electron and ion irradiation-induced dissolution of mechanical twins in the intermetalic U3Si: An in situ HVEM study

1989 ◽  
Vol 47 ◽  
pp. 652-653
Author(s):  
Charles W. Allen ◽  
Robert C. Birtcher
Keyword(s):  
Elevated Temperatures ◽  
Ion Irradiation ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Heavy Ion ◽  
High Energy ◽  
Mechanical Twinning ◽  
In Situ Experiments

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.

The threshold energy for atom displacement in fcc metals

1990 ◽  
Vol 48 (4) ◽  
pp. 530-531
Author(s):  
Wilfried Sigle ◽  
Matthias Hohenstein ◽  
Alfred Seeger
Keyword(s):  
Growth Rate ◽  
Elevated Temperatures ◽  
Threshold Energy ◽  
Dislocation Loops ◽  
Absolute Minimum ◽  
Voltage Electron ◽  
Atom Displacement ◽  
Electron Microscopes ◽  
Fcc Metal

Prolonged electron irradiation of metals at elevated temperatures usually leads to the formation of large interstitial-type dislocation loops. The growth rate of the loops is proportional to the total cross-section for atom displacement,which is implicitly connected with the threshold energy for atom displacement, Ed . Thus, by measuring the growth rate as a function of the electron energy and the orientation of the specimen with respect to the electron beam, the anisotropy of Ed can be determined rather precisely. We have performed such experiments in situ in high-voltage electron microscopes on Ag and Au at 473K as a function of the orientation and on Au as a function of temperature at several fixed orientations.Whereas in Ag minima of Ed are found close to <100>,<110>, and <210> (13-18eV), (Fig.1) atom displacement in Au requires least energy along <100>(15-19eV) (Fig.2). Au is thus the first fcc metal in which the absolute minimum of the threshold energy has been established not to lie in or close to the <110> direction.

In Situ Polymerized Protic Ionogels for Fuel Cells at Elevated Temperatures

2021 ◽  
Author(s):  
Mengdou Zou ◽  
Jie Luo ◽  
Xurui Wang ◽  
Shuai Tan ◽  
Caihong Wang ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Elevated Temperatures

scholarly journals Ultraviolet Absorption Cross-Sections of Ammonia at Elevated Temperatures for Nonintrusive Quantitative Detection in Combustion Environments

2021 ◽  
pp. 000370282199044
Author(s):  
Wubin Weng ◽  
Shen Li ◽  
Marcus Aldén ◽  
Zhongshan Li
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Elevated Temperatures ◽  
Uv Absorption ◽  
Energy Utilization ◽  
Quantitative Detection ◽  
Absorption Cross ◽  
Hot Gas

Ammonia (NH3) is regarded as an important nitrogen oxides (NOx) precursor and also as an effective reductant for NOx removal in energy utilization through combustion, and it has recently become an attractive non-carbon alternative fuel. To have a better understanding of thermochemical properties of NH3, accurate in situ detection of NH3 in high temperature environments is desirable. Ultraviolet (UV) absorption spectroscopy is a feasible technique. To achieve quantitative measurements, spectrally resolved UV absorption cross-sections of NH3 in hot gas environments at different temperatures from 295 K to 590 K were experimentally measured for the first time. Based on the experimental results, vibrational constants of NH3 were determined and used for the calculation of the absorption cross-section of NH3 at high temperatures above 590 K using the PGOPHER software. The investigated UV spectra covered the range of wavelengths from 190 nm to 230 nm, where spectral structures of the [Formula: see text] transition of NH3 in the umbrella bending mode, v2, were recognized. The absorption cross-section was found to decrease at higher temperatures. For example, the absorption cross-section peak of the (6, 0) vibrational band of NH3 decreases from ∼2 × 10−17 to ∼0.5 × 10−17 cm2/molecule with the increase of temperature from 295 K to 1570 K. Using the obtained absorption cross-section, in situ nonintrusive quantification of NH3 in different hot gas environments was achieved with a detection limit varying from below 10 parts per million (ppm) to around 200 ppm as temperature increased from 295 K to 1570 K. The quantitative measurement was applied to an experimental investigation of NH3 combustion process. The concentrations of NH3 and nitric oxide (NO) in the post flame zone of NH3–methane (CH4)–air premixed flames at different equivalence ratios were measured.

scholarly journals Oleacein Intestinal Permeation and Metabolism in Rats Using an In Situ Perfusion Technique

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 719
Author(s):  
Anallely López-Yerena ◽  
Maria Pérez ◽  
Anna Vallverdú-Queralt ◽  
Eleftherios Miliarakis ◽  
Rosa M. Lamuela-Raventós ◽  
...  
Keyword(s):  
Intestinal Permeability ◽  
Model Compound ◽  
Virgin Olive Oil ◽  
Extra Virgin Olive Oil ◽  
Perfusion Technique ◽  
In Situ Perfusion ◽  
First Pass ◽  
Health Promoting ◽  
Intestinal Permeation

Oleacein (OLEA) is one of the most important phenolic compounds in extra virgin olive oil in terms of concentration and health-promoting properties, yet there are insufficient data on its absorption and metabolism. Several non-human models have been developed to assess the intestinal permeability of drugs, among them, single-pass intestinal perfusion (SPIP), which is commonly used to investigate the trans-membrane transport of drugs in situ. In this study, the SPIP model and simultaneous luminal blood sampling were used to study the absorption and metabolism of OLEA in rats. Samples of intestinal fluid and mesenteric blood were taken at different times and the ileum segment was excised at the end of the experiment for analysis by LC–ESI–LTQ–Orbitrap–MS. OLEA was mostly metabolized by phase I reactions, undergoing hydrolysis and oxidation, and metabolite levels were much higher in the plasma than in the lumen. The large number of metabolites identified and their relatively high abundance indicates an important intestinal first-pass effect during absorption. According to the results, OLEA is well absorbed in the intestine, with an intestinal permeability similar to that of the highly permeable model compound naproxen. No significant differences were found in the percentage of absorbed OLEA and naproxen (48.98 ± 12.27% and 43.96 ± 7.58%, respectively).

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