Preparation of polymeric membranes entrapping b-cyclodextrin and their molecular recognition of naringin

An amorphous polyetheretherketone known as PEEK-WC and a beta-cyclodextrin derivative (O-octyloxycarbonyl-beta-CD), insoluble in water, were used to prepare flat sheet membranes by the diffusion induced phase separation. It was found that the beta-CD derivative entrapped in membranes is able to form a complex with naringin, a bitter component present in grapefruits. The recognition properties of the beta-CD derivative immobilized in the PEEK-WC membranes towards naringin have been investigated as a function of the amount of beta-CD derivative present in the casting solution. A significant improvement of the efficiency of the O-octyloxycarbonyl-beta-CD was observed when an inclusion complex with naringin in the membrane was formed compared to when the beta-CD derivative is dispersed in an aqueous solution of naringin. Washing with an alkaline solution allows an easy regeneration of the membranes and permits their reuse. No recognition properties were found for PEEK-WC membranes made without the beta-CD derivative.