Effect of Membrane Thickness of Collodion Coated Activated Charcoal on Adsorption of Small and Middle Molecules

Abstract

Different thicknesses of a cellulose nitrate (CN) coating were applied to petroleum pitch bead activated charcoal. The effect of this on the adsorption of small and middle molecules in vitro was studied. This was done by measuring the rate of adsorption of Vitamin B₁₂creatinine and uric acid from aqueous solution by activated charcoal having CN coatings of varying thickness (0.1% to 4.0% by weight). A CN coating weight of up to 0.2% caused negligible or no decrease in the rate of adsorption of all three solutes as compared with uncoated charcoal. Coating weights greater than 0.2% caused a significant decrease in the rate of adsorption of Vitamin B₁₂and uric acid but had little effect on the rate of adsorption of creatinine. Coating weights greater than 1.8% caused a significant decrease in the rate of adsorption of creatinine.