SOLUTE ADSORPTION FROM WATER ONTO A MODIFIED SORBENT IN WHICH THE HYDROGEN BINDING-SITE IS PROTECTED FROM WATER - THERMODYNAMICS AND SEPARATIONS

The goal of this work was to exploit the specificity of hydrogen bonding for the selective adsorption of solutes from aqueous solution. For this study a porous polycarboxylic ester sorbent was "modified" such that the pores were filled with a nonpolar solvent in order to protect the hydrogen bonding adsorption sites from the water solvent. For solutes to adsorb onto this modified sorbent, they must first partition into the nonpolar pore phase and then adsorb onto the hydrogen bonding sorption site. Using p-cresol-phenylpropanol as a model solute mixture, we observed improved separation factors due to the hydrogen bonding characteristics of the modified sorbent. Also, adsorption equilibrium for this modified sorbent was readily predicted using single solute data and simple thermodynamic relations.