Pore structure of gel chitosan membranes .1. Solute diffusion measurements

The capillary pore model of water-swollen gels was used to interpret solute diffusion through gel chitosan membranes. Diffusive permeability coefficients of 12 solutes ranging in molecular radius from 2.5 Angstrom (methanol) to 14 Angstrom (polyethylene glycol 4000) were measured for an untreated chitosan membrane, for four chitosan membranes crosslinked with glutaraldehyde of concentrations between 0.01 and 1% and coated with a protein and also, for comparison, for a commercial Cuprophan membrane. Through the capillary pore-model correlation of the above coefficients with the membrane water content, the following structural factors of the examined membranes were calculated: pore radius, surface porosity and tortuosity factor. Knowledge of these factors is required if the desired membranes are to be designed for a given application (e.g. dialysis).