Thermally stimulated depolarization current studies of poly(ethylene oxide) and poly(ethylene oxide) complexed with potassium thiocyanate

1985 ◽  
Vol 58 (8) ◽  
pp. 2811-2815 ◽  
Author(s):  
J. P. Calame ◽  
John J. Fontanella ◽  
Mary C. Wintersgill ◽  
Carl G. Andeen
Keyword(s):  
Ethylene Oxide ◽  
Potassium Thiocyanate ◽  
Depolarization Current ◽  
Thermally Stimulated Depolarization Current ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Thermally Stimulated Depolarization

Thermal properties of poly(ethylene oxide) complexed with sodium thiocyanate and potassium thiocyanate

1987 ◽  
Vol 20 (12) ◽  
pp. 3023-3034 ◽  
Author(s):  
C. Robitaille ◽  
S. Marques ◽  
D. Boils ◽  
J. Prud'homme
Keyword(s):  
Thermal Properties ◽  
Ethylene Oxide ◽  
Potassium Thiocyanate ◽  
Sodium Thiocyanate ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Thermally stimulated depolarization current characteristic of EVA–conductive PPy composites

2019 ◽  
Vol 54 (2) ◽  
pp. 205-214 ◽  
Author(s):  
F. S. Thabet ◽  
A. M. AbdElbary ◽  
G. M. Nasr
Keyword(s):  
Vinyl Acetate ◽  
Relaxation Times ◽  
Peak Height ◽  
Depolarization Current ◽  
Thermally Stimulated Depolarization Current ◽  
Poling Temperature ◽  
Temperature Ranges ◽  
Poly Ethylene ◽  
Thermally Stimulated Depolarization ◽  
Pure Poly

Thermally stimulated depolarization current in pure poly(ethylene-co-vinyl acetate) and poly(ethylene-co-vinyl acetate) composites with different amounts of polypyrrole/carbon nanoparticles (of various weight ratios, 100:0, 95:5, 90:10, 85:15, 80:20, and 70:30) have been investigated at poling temperature 363 K using different polarizing voltage. Thermograms of pure and composite samples have two or three peaks over all temperature ranges depending on the polarizing voltage. The decrease in peak height with increased polarized voltage is observed in pure poly(ethylene-co-vinyl acetate) samples loaded with 5%, 10%, 15%, and 30% polypyrrole due to the detrapping of the large amounts of charge results in electrode blocking and decrease in thermally stimulated depolarization current in those samples. The molecular parameters, such as activation energy E, charge released Q, and relaxation times τ0 and τ m for thermally stimulated depolarization current peaks have been estimated.

The Structure of Radiation Cross-Linked Poly (ethylene oxide) Gels

1971 ◽  
Vol 29 ◽  
pp. 76-77
Author(s):  
C. E. Cluthe ◽  
G. G. Cocks
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Parallel Plate ◽  
Average Molecular Weight ◽  
Radical Reaction ◽  
Free Radical Reaction ◽  
Nitrogen Gas ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Initial Viscosity

Aqueous solutions of a 1 weight-per cent poly (ethylene oxide) (PEO) were degassed under vacuum, transferred to a parallel plate viscometer under a nitrogen gas blanket, and exposed to Co60 gamma radiation. The Co60 source was rated at 4000 curies, and the dose ratewas 3.8x105 rads/hr. The poly (ethylene oxide) employed in the irradiations had an initial viscosity average molecular weight of 2.1 x 106.The solutions were gelled by a free radical reaction with dosages ranging from 5x104 rads to 4.8x106 rads.

Preparation of Organized Mesoporous Silica from Sodium Metasilicate Solutions in Alkaline Medium Using Nonionic Surfactants

2003 ◽  
Vol 68 (10) ◽  
pp. 2019-2031 ◽  
Author(s):  
Markéta Zukalová ◽  
Jiří Rathouský ◽  
Arnošt Zukal
Keyword(s):  
Mesoporous Silica ◽  
Ethylene Oxide ◽  
Sodium Metasilicate ◽  
Spherical Particles ◽  
Structure Directing Agent ◽  
Inorganic Species ◽  
Poly Ethylene Oxide ◽  
Acidic Conditions ◽  
Poly Ethylene ◽  
Hydrolysis Of

A new procedure has been developed, which is based on homogeneous precipitation of organized mesoporous silica from an aqueous solution of sodium metasilicate and a nonionic poly(ethylene oxide) surfactant serving as a structure-directing agent. The decrease in pH, which induces the polycondensation of silica, is achieved by hydrolysis of ethyl acetate. Owing to the complexation of Na+ cations by poly(ethylene oxide) segments, assembling of the mesostructure appears to occur under electrostatic control by the S0Na+I- pathway, where S0 and I- are surfactant and inorganic species, respectively. As the complexation of Na+ cations causes extended conformation of poly(ethylene oxide) segments, the pore size and pore volume of organized mesoporous silica increase in comparison with materials prepared under neutral or acidic conditions. The assembling of particles can be fully separated from their solidification, which results in the formation of highly regular spherical particles of mesoporous silica.

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