Oxygen diffusion via cobalt-porphyrin complexes fixed in a polymer matrix

1988 ◽  
Vol 92 (22) ◽  
pp. 6461-6464 ◽  
Author(s):  
Eishun Tsuchida ◽  
Hiroyuki Nishide ◽  
Manshi Ohyanagi ◽  
Osamu Okada
Keyword(s):  
Polymer Matrix ◽  
Oxygen Diffusion ◽  
Cobalt Porphyrin

Effect of polymer matrix on the oxygen diffusion via a cobalt porphyrin fixed in a membrane

1991 ◽  
Vol 24 (23) ◽  
pp. 6306-6309 ◽  
Author(s):  
Hiroyuki Nishide ◽  
Hiroyoshi Kawakami ◽  
Takayuki Suzuki ◽  
Yasutaka Azechi ◽  
Yuji Soejima ◽  
...  
Keyword(s):  
Polymer Matrix ◽  
Oxygen Diffusion ◽  
Cobalt Porphyrin

Activation barriers for oxygen diffusion in polystyrene and polycarbonate glasses: effects of codissolved argon, helium, and nitrogen

1995 ◽  
Vol 73 (11) ◽  
pp. 1831-1840 ◽  
Author(s):  
Bojie Wang ◽  
Peter R. Ogilby
Keyword(s):  
Diffusion Coefficient ◽  
Polymer Matrix ◽  
Diffusion Coefficients ◽  
Oxygen Diffusion ◽  
Arrhenius Plot ◽  
Activation Barrier ◽  
Spectroscopic Technique ◽  
Activation Barriers ◽  
Data Yield ◽  
Diffusion Activation

A recently developed spectroscopic technique was used to determine oxygen diffusion coefficients as a function of temperature for polystyrene and polycarbonate films. Data were recorded at total pressures <300 Torr over the temperature range 5–45 °C under conditions in which argon, helium, and nitrogen, respectively, were copenetrants. In all cases, the presence of the additional gas caused an increase in the oxygen diffusion coefficient. Arrhenius plots of the data yield (a) a diffusion activation barrier, Eact, and (b) a diffusion coefficient, D0, that represents the condition of "barrier-free" gas transport for the temperature domain over which the Arrhenius plot is linear. For all cases examined in both polystyrene and polycarbonate, D0 increased with an increase in the partial pressure of added gas. In polystyrene, the presence of an additional gas did not change Eact. In polycarbonate, Eact obtained in the presence of helium and argon likewise did not differ from that obtained in the absence of the copenetrant. When nitrogen was the added gas, however, a larger value of Eact was obtained. This latter observation is interpreted to reflect the plasticization of polycarbonate by nitrogen. Eact and D0 data are discussed within the context of a model that distinguishes between dynamic and static elements of free volume in the polymer matrix. Keywords: oxygen diffusion, polystyrene, polycarbonate, activation barrier.

Enhanced Oxygen Diffusion through a Porous Membrane Chemically Modified with Cobalt Porphyrin on Its Pore Surface

1994 ◽  
Vol 116 (10) ◽  
pp. 4503-4504 ◽  
Author(s):  
Hiroyuki Nishide ◽  
Takayuki Suzuki ◽  
Ryuji Nakagawa ◽  
Eishun Tsuchida
Keyword(s):  
Oxygen Diffusion ◽  
Porous Membrane ◽  
Pore Surface ◽  
Cobalt Porphyrin ◽  
Chemically Modified

Time-monitoring sensor based on oxygen diffusion in an indicator/polymer matrix

2013 ◽  
Vol 178 ◽  
pp. 254-262 ◽  
Author(s):  
Peter Marek ◽  
Juan Jesús Velasco-Veléz ◽  
Thomas Haas ◽  
Theodor Doll ◽  
Gabriele Sadowski
Keyword(s):  
Polymer Matrix ◽  
Oxygen Diffusion

Low-temperature annealing of YBa2Cu3O7-x

1992 ◽  
Vol 50 (1) ◽  
pp. 88-89
Author(s):  
R.L. Sabatini ◽  
Yimei Zhu ◽  
Masaki Suenaga ◽  
A.R. Moodenbaugh
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Oxygen Diffusion ◽  
Diffusion Rate ◽  
Oxygen Depletion ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Microstructural Effects ◽  
Oxygen Diffusion Rate

Low temperature annealing (<400°C) of YBa2Cu3O7x in a ozone containing oxygen atmosphere is sometimes carried out to oxygenate oxygen deficient thin films. Also, this technique can be used to fully oxygenate thinned TEM specimens when oxygen depletion in thin regions is suspected. However, the effects on the microstructure nor the extent of oxygenation of specimens has not been documented for specimens exposed to an ozone atmosphere. A particular concern is the fact that the ozone gas is so reactive and the oxygen diffusion rate at these temperatures is so slow that it may damage the specimen by an over-reaction. Thus we report here the results of an investigation on the microstructural effects of exposing a thinned YBa2Cu3O7-x specimen in an ozone atmosphere using transmission electron microscopy and energy loss spectroscopy techniques.

Polymer matrix composites and technology

2011 ◽  
Author(s):  
Ru-Min Wang ◽  
Shui-Rong Zheng ◽  
Ya-Ping Zheng
Keyword(s):  
Polymer Matrix ◽  
Polymer Matrix Composites ◽  
Matrix Composites
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