Determination of Diffusion Coefficients of Gases Through a Flat Polymeric Membrane by the Method of Non-Linear Regression

Non-linear regression was applied for calculation of diffusion coefficients of gases through a flat polymeric membrane from the experimental data obtained by the flow permeation method with the thermal conductivity detection of composition of gaseous mixture. to verify this method a polyethylene and carbon dioxide was chosen. Diffusion coefficients of carbon dioxide in the low-density polyethylene of two different thickness at the temperature of 25 °C were determined with precision about ±2.5% in agreement with literature.