Oxygen permeation constant

Film Forming and Selective Oxygen Permeation. Selective oxygen permeation was evaluated mainly for the polymers having short ollgoslloxane side chains. Oxygen permeation constants (Pq ) 1... 

If the oxygen permeation constant and the rate of oxygen consumption for the material remain relatively constant as a function of total absorbed dose, a steady state in heterogeneous oxidation will be approached. If the rate of oxygen consumption by reaction with free radicals generated by the radiation exceeds the rate of supply of oxygen from the edges of the polymer sample, distinct... 

The main fluids of interest with plastics are oxygen and water vapour (for packaging applications) and CO2 (for carbonated drinks applications). Fig. 1.13 and Fig. 1.14 illustrate the type of behaviour exhibited by a range of plastics. In some cases it is necessary to use multiple layers of plastics because no single plastic offers the combination of price, permeation resistance, printability, etc. required for the application. When multi-layers are used, an overall permeation constant for the composite wall may be obtained from... 

It appears that regardless of the film material involved, oxygen permeates about four times a fast as nitrogen, and carbon dioxide about 25 times as fast. The fact that the ratios of the permeabilities for all gases, apart from water vapor, are remarkably constant, provided there is no interaction between the film material and the diffusing gas, leads one to express the permeability as the product of three factors [49] one determined by the nature of the polymer film, one determined by the nature of the gas, and one accounting for the interaction between the gas and the film i.e.. 

Molar flow rate of air feed and the sweep gas Oxygen permeation rate Reverse surface exchange reaction rate constant... 

Another approach has been to correlate the oxygen permeation flux to oxygen partial pressures pelectronic conductivity is high and constant within the MIEC membrane, the oxygen flux can be written as ... 

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