Low Temperature Expansion of Polysulfide Rubbers

1966 ◽  
Vol 39 (2) ◽  
pp. 211-216
Author(s):  
B. A. Hunter ◽  
M. J. Kleinfeld
Keyword(s):  
Room Temperature ◽  
Liquid Mixture ◽  
Cumene Hydroperoxide ◽  
Polymer Chains ◽  
Nitrogen Gas ◽  
Blowing Agents ◽  
Disulfide Linkages ◽  
Novel Method ◽  
Rubber Product ◽  
Liquid Polysulfide Rubbers

Abstract A novel method for producing a cellular cured rubber product at room temperature has been developed. Pourable liquid polysulfide polymers are treated with a conventional oxidizing curative and selected water-sensitive or oxidation-sensitive blowing agents. Standing at ambient temperature the viscous liquid mixture gradually “rises” and cures to form a finely porous cellular rubber product. Conventional curatives employed include oxidizing agents such as lead peroxide and cumene hydroperoxide. These convert terminal or pendant thiol groups in the polysulfide polymer chains to chain-connecting disulfide linkages. Water is a byproduct of the curing reaction. In the presence of water-sensitive blowing agents such as, (1) metal salts of azodicarboxylic acid or, (2) metal hydride compounds the water produced in the cure reacts to form copious amounts of nitrogen or of hydrogen. Alternatively, oxidation-sensitive blowing agents such as p, p′-oxybis-(benzene sulfonyl hydrazide) react directly with the oxidizing curative to form nitrogen gas. The blowing reactions are concurrent with cure and efficient and controllable expansion can be achieved. The unique process offers possible economies and special properties in applications of liquid polysulfide rubbers as potting compounds, joint sealants, solvent resistant forms, and cold casting compounds.

Influence of the Annealing Ambient on Structural and Optical Properties of Rare Earth Implanted GaN

2005 ◽  
Vol 892 ◽  
Author(s):  
Katharina Lorenz ◽  
E. Nogales ◽  
R. Nédélec ◽  
J. Penner ◽  
R. Vianden ◽  
...  
Keyword(s):  
Optical Properties ◽  
Rare Earth ◽  
Room Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Strong Increase ◽  
Structural And Optical Properties ◽  
Nitrogen Gas ◽  
Higher Temperature ◽  
The Eu ◽  
The Rare Earth

AbstractGaN films were implanted with Er and Eu ions and rapid thermal annealing was performed at 1000, 1100 and 1200 °C in vacuum, in flowing nitrogen gas or a mixture of NH3 and N2. Rutherford backscattering spectrometry in the channeling mode was used to study the evolution of damage introduction and recovery in the Ga sublattice and to monitor the rare earth profiles after annealing. The surface morphology of the samples was analyzed by scanning electron microscopy and the optical properties by room temperature cathodoluminescence (CL). Samples annealed in vacuum and N2 already show the first signs of surface dissociation at 1000 °C. At higher temperature, Ga droplets form at the surface. However, samples annealed in NH3 + N2 exhibit a very good recovery of the lattice along with a smooth surface. These samples also show the strongest CL intensity for the rare earth related emissions in the green (for Er) and red (for Eu). After annealing at 1200 °C in NH3+N2 the Eu implanted sample reveals the channeling qualities of an unimplanted sample and a strong increase of CL intensity is observed.

Room Temperature Ferromagnetism and Optical Limiting in V2O5 Nanoflowers Synthesized by a Novel Method

2010 ◽  
Vol 115 (1) ◽  
pp. 112-117 ◽  
Author(s):  
Manas R. Parida ◽  
C. Vijayan ◽  
C. S. Rout ◽  
C. S. Suchand Sandeep ◽  
Reji Philip ◽  
...  
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Optical Limiting ◽  
Novel Method

Reversibility of Lithium Secondary Batteries Using a Room-Temperature Ionic Liquid Mixture and Lithium Metal

2005 ◽  
Vol 8 (11) ◽  
pp. A577 ◽  
Author(s):  
Shiro Seki ◽  
Yo Kobayashi ◽  
Hajime Miyashiro ◽  
Yasutaka Ohno ◽  
Yuichi Mita ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Room Temperature ◽  
Liquid Mixture ◽  
Room Temperature Ionic Liquid ◽  
Lithium Metal ◽  
Lithium Secondary Batteries

InN PHOTOCONDUCTORS ON DIFFERENT ORIENTATIONS OF Si SUBSTRATES

2012 ◽  
Vol 26 (31) ◽  
pp. 1250137 ◽  
Author(s):  
M. AMIRHOSEINY ◽  
Z. HASSAN ◽  
S. S. NG ◽  
L. S. CHUAH ◽  
M. A. AHMAD ◽  
...  
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Ohmic Contact ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Indium Nitride ◽  
Rf Sputtering ◽  
Nitrogen Gas ◽  
Si Substrates ◽  
Current Voltage

We have fabricated photoconductors of indium nitride (InN) grown by radio frequency (RF) sputtering. The InN thin films were deposited on Si (100), Si (110) and Si (111) substrates at room temperature. The Ag/Al contact has been deposited by thermal evaporation in vacuum (10-5 Torr ) and then annealed under the flowing of the nitrogen gas environment in order to relieve stress and also induce any favorable reactions between metals and the semiconductor. Current–voltage (I–V) measurements after heat treatment at 400°C were carried out for samples in dark and illumination conditions. It was found that Ag/Al formed a good ohmic contact on top of InN . In addition, the characteristics of the contacts were significantly affected by the orientation of substrates.

Reactive Sputtering Growth and Characterizations of InN Thin Films on Si Substrates

2012 ◽  
Vol 545 ◽  
pp. 290-293
Author(s):  
Maryam Amirhoseiny ◽  
Hassan Zainuriah ◽  
Ng Shashiong ◽  
Mohd Anas Ahmad
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Rf Magnetron Sputtering ◽  
Rf Power ◽  
X Ray Diffraction ◽  
Nitrogen Gas ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force

We have studied the effects of deposition conditions on the crystal structure of InN films deposited on Si substrate. InN thin films have been deposited on Si(100) substrates by reactive radio frequency (RF) magnetron sputtering method with pure In target at room temperature. The nitrogen gas pressure, applied RF power and the distance between target and substrate were 2×10-2 Torr, 60 W and 8 cm, respectively. The effects of the Ar–N2 sputtering gas mixture on the structural properties of the films were investigated by using scanning electron microscope, energy-dispersive X-ray spectroscopy, atomic force microscopy and X-ray diffraction techniques.

Binding to semiflexible polymers: a novel method to control the structures of small numbers of building blocks

Soft Matter ◽  
2014 ◽  
Vol 10 (38) ◽  
pp. 7661-7668 ◽  
Author(s):  
Dong Zhang ◽  
Linxi Zhang
Keyword(s):  
Elastic Medium ◽  
Building Blocks ◽  
Spatial Arrangement ◽  
Relative Orientation ◽  
Polymer Chains ◽  
Semiflexible Polymers ◽  
Spherical Building ◽  
Local Organization ◽  
Semiflexible Polymer ◽  
Novel Method

Semiflexible polymer chains can serve as an effective soft elastic medium to control the structures of small numbers of building blocks through three different aspects: local organization of two neighbor particles, spatial arrangement of small numbers of building blocks, and the relative orientation of neighboring non-spherical building blocks.

Discotic liquid crystals of transition metal complexes, part 36: syntheses and mesomorphic properties of very large discotic liquid crystals based on triphenylenocyanine and 1,4-diazatriphenylenocyanine

2006 ◽  
Vol 10 (09) ◽  
pp. 1145-1155 ◽  
Author(s):  
Masahiro Ichihara ◽  
Masakazu Miida ◽  
Bernhard Mohr ◽  
Kazuchika Ohta
Keyword(s):  
Liquid Crystals ◽  
Room Temperature ◽  
Optical Microscope ◽  
Decomposition Temperature ◽  
Discotic Liquid Crystals ◽  
Large Area ◽  
Scanning Calorimetry ◽  
Nitrogen Gas ◽  
Homeotropic Alignment ◽  
Mesomorphic Properties

Two series of very large discotic complexes of tetrakis (2,3,6,7-tetraalkoxy)triphenylenocyaninato copper(II) (abbreviated as ( C n O )16 TcCu ; n = 8, 10, 12 and 14) and tetrakis(2,3,6,7-tetraalkoxy)-1,4-diazatriphenylenocyaninato copper(II) (abbreviated as ( C n O )16 TzCu ; n = 8, 10, 12 and 14), were synthesized to investigate their mesomorphic properties by differential scanning calorimetry, thermogravimetry analysis, polarizing optical microscope observation and temperature-dependent X-ray studies. The results show that each of the ( C n O )16 TcCu derivatives exhibits two or three disordered rectangular columnar ( Col rd ) mesophases from room temperature to the decomposition temperature at ca. 330-340°C under nitrogen gas. However, each of the ( C n O )16 TzCu complexes exhibits only one ordered tetragonal columnar ( Col tet.o ) mesophase in an extremely wide temperature region from room temperature to the decomposition temperature at ca 300°C and ca. 340-350°C under the atmosphere and nitrogen gas, respectively. It is very interesting that the Col tet.o mesophase of ( C n O )16 TzCu for n = 10, 12 and 14 shows remarkable spontaneous homeotropic alignment in a large area, without disclinations and polydomains, in the temperature range from room temperature to the decomposition temperature. As far as we know, these discotic liquid crystals are the first examples to show homeotropic alignment at room temperature. Furthermore, the difference between the mesomorphic properties of ( C n O )16 TcCu and ( C n O )16 TzCu originated only from the additional eight nitrogen atoms in the central core in ( C n O )16 TzCu .

scholarly journals HATCHABILITY OF STORED CHICKEN EGGS AS AFFECTED BY DAILY TURNING DURING STORAGE AND PREWARMING AND VACUUMING EGGS ENCLOSED IN PLASTIC WITH NITROGEN

1966 ◽  
Vol 46 (1) ◽  
pp. 47-50 ◽  
Author(s):  
F. G. Proudfoot
Keyword(s):  
Room Temperature ◽  
Storage Period ◽  
Nitrogen Gas ◽  
Positional Change ◽  
Hatching Eggs ◽  
Chicken Eggs

Three experiments were conducted to study hatchability as affected by (1) daily turning of eggs in storage as compared with no positional change using eggs stored 14, 21, and 28 days, (2) prewarming eggs at 21–24 °C for 18 hours prior to setting compared with eggs set directly from the egg cooler using eggs enclosed in Cryovac and flushed with nitrogen gas prior to storage for 14, 21, and 28 days, and (3) vacuuming of eggs enclosed in Cryovac flushed with nitrogen gas compared with a Cryovac package inflated with nitrogen prior to storage for 21 and 28 days.A daily positional change of hatching eggs during storage resulted in improved hatchability compared with no positional change. Prewarming Cryovac-packed, nitrogen-flushed, hatching eggs for 18 hours at room temperature resulted in higher hatchability compared with eggs set directly from an egg cooler operated at 10–12 °C. A storage period × prewarming interaction suggests that when eggs are stored for 14 days or less, prewarming is not beneficial, but if the storage period exceeds 14 days then prewarming enhances hatchability. Vacuuming Cryovac-packaged, nitrogen-flushed, hatching eggs prior to storage for 21 and 28 days did not improve hatchability, probably because the oxygen had been effectively removed by the "nitrogen-flush".

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