Studies Related to the Extraction of Lignosulfonate Using a Supported LiquidMembrane

摘要

In the thesis the use of a supported liquid membrane to extract lignosulfonate isdevised. Mathematical models are developed to describe the two types of carrier-mediated transport of lignosulfonate studied experimentally. A rotating diffusion cell is used to show that the formation of trilaurylamine hydrochloride during the extraction process in the co-transport mode is fast compared to diffusion processes. A method based on a convective diffusion process across a porous membrane is used to study the conformation of lignosulfonate molecules in aqueous solutions. The molecules swell considerably when the relative permittivity is lowered by adding ethanol and when an external electric field is applied. The effective charges of the polyelectrolyte molecules drop to zero when the temperature is raised to 40 C. An improved method to allow measurements of diffusion coefficients and effective charge numbers of lignosulfonate molecules in ternary electrolyte systems is presented and tested.