SELECTIVE ADSORPTION OF SOLUTES BASED ON HYDROGEN-BONDING

Current evidence suggests that adsorption of solutes from a nonpolar solvent onto a polycarboxylic ester sorbent involves the formation of a hydrogen bond. This bond appears to be formed between a hydrogen atom of the solute and the carbonyl group of the sorbent. From studies involving single solutes it was observed that the primary amine aniline adsorbed nearly twice as much as the secondary amine N-methylaniline. The tertiary amine N,N-dimethylaniline, which does not contain a nitrogen-bonded hydrogen atom, was unable to bind to the sorbent. In studies involving mixtures, solutes were observed to be selectively adsorbed based on their hydrogen bonding abilities. A simple thermodynamic model which was developed to explain this adsorption was capable of accurately predicting separation factors for the selective adsorption of solutes from solute mixtures. © 1990, Taylor & Francis Group, LLC. All rights reserved.