A Study of Diffusion Processes in Liquids using Hyperspectral Digital Imaging

We present the application of hyperspectral digital imaging (HSDI) for the study of diffusion processes in solutions absorbing radiation in the ultraviolet, visible and near infrared ranges. A capillary tube was filled with a solution of radiation adsorbing substance (RAS, K 2Cr207) and connected to a vessel without the RAS. The change in solute concentration (as indicated by transmittance) in the capillary was followed by imaging with a sensitive CCD camera at specific intervals. The digital detector and computer image analysis used in this HSDI method allows the collection of precise information about diffusion profiles and the determination of diffusion coefficients in a relatively short time.