Determination Of Diffusion Coefficients In A Liquid In Sn System PDF Download

Liquid diffusion coefficients for systems approximating gas chromatographic sample -- liquid phase systems were determined by using multiple internal reflectance infrared spectroscopy. An expression for the diffusion coefficient as a function of the change of concentration with time was developed from Fick T s second lav; and Jost T s treatment for diffusion into a slab. By using cell covers designed for this project (for FMIR solid sampling cell) and by turning the spectrophotometer (Infracord) on its side, it was possible to measure the change of concentration of solute (fed as vapour in carrier gas) in a layer of solvent with time spectrophotometrically and to thus determine the diffusion coefficient of the solute- solvent system. The systems used in the project included those of different solutes in fluorolube and acetone in solvents of varying viscosities. An attempt was made to qualitatively evaluate the data by correlation with known values and values expected from empirical expressions. The results indicate that this method provides qualitative values for diffusion coefficients with main errors due to the preparation of the solvent layer.