Catalytic behaviour of carbonate β-CD entrapped in PEEK-WC membranes

O-octyloxycarbonyl beta-cyclodextrins were immobilised in flat sheet PEEK-WC membranes. The membranes were prepared by phase inversion method and characterised. beta-cyclodextrin (beta-CD) catalytic action in the p-nitrophenylacetate (PNPA) hydrolysis to p-nitrophenol (PNP) was studied. The beta-CD acylic carbonate derivative shows an effective catalytic action when incorporated in PEEK-WC membranes, by showing an enzyme-like behaviour. The membranes were tested at different temperatures and substrate concentrations and the value of activation energy for the reaction was estimated. It is well known that beta-CD have a catalytic action, but their immobilisation in a polymeric matrix enhances the reaction rate, in fact the entrapment optimises the interaction with the substrate and increases the chemical stability of the catalyst. In addition, beta-CD show more stability when incorporated in the membrane, because of their chemical resistance to alkaline attack.