Photocrosslinking of EPDM Elastomers. A New Method for Rapid Curing of Elastomer Coatings at Room Temperature

1988 ◽  
Vol 61 (4) ◽  
pp. 568-576 ◽  
Author(s):  
J. Hilborn ◽  
B. Rånby
Keyword(s):  
Room Temperature ◽  
Uv Light ◽  
Steel Substrate ◽  
New Method ◽  
Practical Applications ◽  
Optimum Formulation ◽  
Thick Layers

Abstract Photocrosslinking with UV light in air of silica-filled EPDM rubbers is possible in practical applications for at least 2 mm thick layers which are cemented onto a steel substrate. To find the optimum formulation of the rubber composition, it is essential to know the function of each component. Further optimization can be achieved by using the APOE to the TMPTA system and by using a suitable primer cement on the metal.

Characterization of intergranular cuprous oxide in polycrystalline YBa2Cu3O7-x

1988 ◽  
Vol 46 ◽  
pp. 880-881
Author(s):  
Bradley L. Thiel ◽  
Chan Han R. P. ◽  
Kurosky L. C. Hutter ◽  
I. A. Aksay ◽  
Mehmet Sarikaya
Keyword(s):  
Grain Boundary ◽  
Cuprous Oxide ◽  
Room Temperature ◽  
Boundary Phase ◽  
Spectroscopic Techniques ◽  
Transition Width ◽  
Practical Applications ◽  
Thin Foils ◽  
Superconducting Oxides

The identification of extraneous phases is important in understanding of high Tc superconducting oxides. The spectroscopic techniques commonly used in determining the origin of superconductivity (such as RAMAN, XPS, AES, and EXAFS) are surface-sensitive. Hence a grain boundary phase several nanometers thick could produce irrelevant spectroscopic results and cause erroneous conclusions. The intergranular phases present a major technological consideration for practical applications. In this communication we report the identification of a Cu2O grain boundary phase which forms during the sintering of YBa2Cu3O7-x (1:2:3 compound).Samples are prepared using a mixture of Y2O3. CuO, and BaO2 powders dispersed in ethanol for complete mixing. The pellets pressed at 20,000 psi are heated to 950°C at a rate of 5°C per min, held for 1 hr, and cooled at 1°C per min to room temperature. The samples show a Tc of 91K with a transition width of 2K. In order to prevent damage, a low temperature stage is used in milling to prepare thin foils which are then observed, using a liquid nitrogen holder, in a Philips 430T at 300 kV.

ALCHEMI of B2-Ordered Fe50Al45Me5 alloys

1996 ◽  
Vol 54 ◽  
pp. 548-549
Author(s):  
Ian M. Anderson
Keyword(s):  
Room Temperature ◽  
Iron Aluminide ◽  
Low Density ◽  
Intermetallic Alloys ◽  
Practical Applications ◽  
Alloying Additions ◽  
Site Distribution ◽  
Good Corrosion Resistance ◽  
Room Temperature Ductility ◽  
The Matrix

B2-ordered iron aluminide intermetallic alloys exhibit a combination of attractive properties such as low density and good corrosion resistance. However, the practical applications of these alloys are limited by their poor fracture toughness and low room temperature ductility. One current strategy for overcoming these undesirable properties is to attempt to modify the basic chemistry of the materials with alloying additions. These changes in the chemistry of the material cannot be fully understood without a knowledge of the site-distribution of the alloying elements. In this paper, the site-distributions of a series of 3d-transition metal alloying additions in B2-ordered iron aluminides are studied with ALCHEMI.A series of seven alloys of stoichiometry Fe50AL45Me5, with Me = {Ti, V, Cr, Mn, Co, Ni, Cu}, were prepared with identical heating cycles. Microalloying additions of 0.2% B and 0.1% Zr were also incorporated to strengthen the grain boundaries, but these alloying additions have little influence on the matrix chemistry and are incidental to this study.

Non-adhesive lotus and other hydrophobic materials

2008 ◽  
Vol 366 (1870) ◽  
pp. 1539-1556 ◽  
Author(s):  
David Quéré ◽  
Mathilde Reyssat
Keyword(s):  
Solid Surface ◽  
Room Temperature ◽  
Water Repellency ◽  
Short Review ◽  
Water Repellent ◽  
Practical Applications ◽  
Hydrophobic Materials ◽  
Volatile Liquid ◽  
Air Cushion ◽  
The Stability

Superhydrophobic materials recently attracted a lot of attention, owing to the potential practical applications of such surfaces—they literally repel water, which hardly sticks to them, bounces off after an impact and slips on them. In this short review, we describe how water repellency arises from the presence of hydrophobic microstructures at the solid surface. A drop deposited on such a substrate can float above the textures, mimicking at room temperature what happens on very hot plates; then, a vapour layer comes between the solid and the volatile liquid, as described long ago by Leidenfrost. We present several examples of superhydrophobic materials (either natural or synthetic), and stress more particularly the stability of the air cushion—the liquid could also penetrate the textures, inducing a very different wetting state, much more sticky, due to the possibility of pinning on the numerous defects. This description allows us to discuss (in quite a preliminary way) the optimal design to be given to a solid surface to make it robustly water repellent.

scholarly journals Zirconium-Doped Chromium IV Oxide Nanocomposites: Synthesis, Characterization, and Photocatalysis towards the Degradation of Organic Dyes

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 117
Author(s):  
Zahir Muhammad ◽  
Farman Ali ◽  
Muhammad Sajjad ◽  
Nisar Ali ◽  
Muhammad Bilal ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Solid State ◽  
Room Temperature ◽  
Organic Dyes ◽  
Uv Light ◽  
Heterogeneous Photocatalysis ◽  
Ft Ir ◽  
Complete Mineralization

Degradation of organic dyes and their byproducts by heterogeneous photocatalysts is an essential process, as these dyes can be potentially discharged in wastewater and threaten aquatic and xerophyte life. Therefore, their complete mineralization into nontoxic components (water and salt) is necessary through the process of heterogeneous photocatalysis. In this study, Zr/CrO2 (Zirconium-doped chromium IV oxide) nanocomposite-based photocatalysts with different compositions (1, 3, 5, 7 & 9 wt.%) were prepared by an environmentally friendly, solid-state reaction at room temperature. The as-prepared samples were calcined under air at 450 °C in a furnace for a specific period of time. The synthesis of Zr/CrO2 photocatalysts was confirmed by various techniques, including XRD, SEM, EDX, FT-IR, UV-Vis, and BET. The photocatalytic properties of all samples were tested towards the degradation of methylene blue and methyl orange organic dyes under UV light. The results revealed a concentration-dependent photocatalytic activity of photocatalysts, which increased the amount of dopant (up to 5 wt.%). However, the degradation efficiency of the catalysts decreased upon further increasing the amount of dopant due to the recombination of holes and photoexcited electrons.

Cholinium-amino acid based ionic liquids: a new method of synthesis and physico-chemical characterization

2015 ◽  
Vol 17 (32) ◽  
pp. 20687-20698 ◽  
Author(s):  
Serena De Santis ◽  
Giancarlo Masci ◽  
Francesco Casciotta ◽  
Ruggero Caminiti ◽  
Eleonora Scarpellini ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Amino Acid ◽  
Room Temperature ◽  
Chemical Characterization ◽  
New Method ◽  
Room Temperature Ionic Liquids ◽  
Synthetic Method ◽  
Chemical Structures ◽  
Physico Chemical ◽  
Wide Range

Fourteen cholinium-amino acid based room temperature ionic liquids were prepared using a cleaner synthetic method. Chemicophysical properties were well correlated with the wide range of amino acid chemical structures.

ROOM TEMPERATURE PHOTOLUMINESCENCE OF POLYCRYSTALLINE SIC PREPARED FROM CARBON-SATURATED SI MELT

2002 ◽  
Vol 16 (06n07) ◽  
pp. 1047-1051
Author(s):  
JIANPING MA ◽  
ZHIMING CHEN ◽  
GANG LU ◽  
MINGBIN YU ◽  
LIANMAO HANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Uv Light ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Composition And Structure ◽  
Light Excitation ◽  
Scanning Electron

Intense photoluminescence (PL) has been observed at room temperature from the polycrystalline SiC samples prepared from carbon-saturated Si melt at a temperature ranging from 1500 to 1650°C. Composition and structure of the samples have been confirmed by means of X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. PL measurements with 325 nm UV light excitation revealed that the room temperature PL spectrum of the samples consists of 3 luminescent bands, the peak energies of which are 2.38 eV, 2.77 eV and 3.06 eV, respectively. The 2.38 eV band is much stronger than the others. It is suggested that some extrinsic PL mechanisms associated with defect or interface states would be responsible to the intensive PL observed at room temperature.

UV-Light-Induced Dehydrogenative N-Acylation of Amines with 2-Nitrobenzaldehydes to Give 2-Aminobenzamides

Synthesis ◽  
2022 ◽  
Author(s):  
Dishu Zeng ◽  
Tianbao Yang ◽  
Niu Tang ◽  
Wei Deng ◽  
Jiannan Xiang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Organic Synthesis ◽  
Efficient Method ◽  
Building Block ◽  
Room Temperature ◽  
Uv Light ◽  
Amino Acid Derivatives ◽  
One Pot ◽  
Plausible Mechanism ◽  
High Yields

A simple, mild, green and efficient method for the synthesis of 2-aminobenzamides was highly desired in organic synthesis. Herein, we developed an efficient, one-pot strategy for the synthesis of 2-aminobenzamides with high yields irradiated by UV light. 32 examples proceeded successfully by this photo-induced protocol. The yield reached up to 92%. The gram scale was also achieved easily. This building block could be applied in the preparation of quinazolinones derivatives. Amino acid derivatives could be employed smoothly at room temperature. Finally, a plausible mechanism was proposed.

A Novel and Efficient Alkoxylselenenylation of Alkenes

2019 ◽  
Vol 41 (6) ◽  
pp. 1039-1039
Author(s):  
Yingguo Fang and Jie Yan Yingguo Fang and Jie Yan
Keyword(s):  
Room Temperature ◽  
Electrophilic Addition ◽  
New Method ◽  
Reaction Conditions ◽  
Selenium Species

A novel and efficient alkoxylselenenylation from alkenes, diselenides, and alcohols mediated by iodine is developed, with which a series of β-alkoxy selenides are synthesized. In this procedure, firstly, I2 reacts with diselenide to form in situ the active electrophilic selenium species RSeI, then following an electrophilic addition of it to alkenes provides β-alkoxy selenides with high regioselectivity and in good yields. This new method for achieving β-alkoxy selenides has some advantages over other methods such as using available and cheap iodine as the oxidizing species at room temperature, which makes this reaction has milder reaction conditions and simpler procedure.

High Temperature High Current Gain IC Compatible 4H-SiC Phototransistor

2019 ◽  
Vol 963 ◽  
pp. 832-836 ◽  
Author(s):  
Shuo Ben Hou ◽  
Per Erik Hellström ◽  
Carl Mikael Zetterling ◽  
Mikael Östling
Keyword(s):  
High Temperature ◽  
Integrated Circuits ◽  
Room Temperature ◽  
Uv Light ◽  
Optical Power ◽  
Current Gain ◽  
High Current ◽  
Promising Candidate ◽  
Forward Current ◽  
On Chip

This paper presents our in-house fabricated 4H-SiC n-p-n phototransistors. The wafer mapping of the phototransistor on two wafers shows a mean maximum forward current gain (βFmax) of 100 at 25 °C. The phototransistor with the highest βFmax of 113 has been characterized from room temperature to 500 °C. βFmax drops to 51 at 400 °C and remains the same at 500 °C. The photocurrent gain of the phototransistor is 3.9 at 25 °C and increases to 14 at 500 °C under the 365 nm UV light with the optical power of 0.31 mW. The processing of the phototransistor is same to our 4H-SiC-based bipolar integrated circuits, so it is a promising candidate for 4H-SiC opto-electronics on-chip integration.

Electronic Spectral Investigations upon the Photochemical Transformations of Some Substituted 1-(N,N-bisacyl)amino-4,5-diphenyl-l,2,3-triazoles

2001 ◽  
Vol 56 (6-7) ◽  
pp. 452-458
Author(s):  
Irina Petkova ◽  
Apostolos J. Maroulis ◽  
Constantina Hadjiantoniou-Maroulis ◽  
Peter Nikolov
Keyword(s):  
Steady State ◽  
Room Temperature ◽  
Uv Light ◽  
Uv Absorption ◽  
Luminescence Spectra ◽  
Model Compounds ◽  
Photochemical Transformations ◽  
Absorption And Luminescence Spectra ◽  
Photochemical Properties ◽  
Substituted 1

Abstract The objective of this report is to investigate the steady state and dynamic photophysical and photochemical properties of 1-(N,N-bisacyl)amino-4,5-diphenyl-1,2,3-triazoles in solvents of dif­ferent polarity at room temperature and in frozen matrix at 77 K. On the basis of the comparison of their UV absorption and luminescence spectra with those of 4,5-diphenyl-1,2,3-triazole and diben-zamide (model compounds), cleavage of the N-N bond in the title compounds after irradiation with polychrome UV light is proved.

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