Effect of the surface parameters on the interaction of epoxy polymer supports with a lipase enzyme

Abstract

Four porous polymeric supports prepared from epoxy monomers have been analyzed with respect to their catalytic behavior and characterized by means of infrared spectroscopy (FTIR-ATR), nitrogen adsorption and Inverse Gas Chromatography at Infinite Dilution (IGC-ID). The Pseudomonas stutzeri lipase has been used to determine the adsorption and desorption rates on each support. It has been found that the specific surface area increases with the number of epoxy groups and the pore volume increases as well. The surface energies are also related with the number of epoxy groups in the monomer and show a decrease in the dispersive component of the surface energy, γ S d , from 104.87 to 71.12 mJ m−2, but an increase in the polar or acid–base characteristics. Regarding the adsorption–desorption rates of the enzyme lipase, it occurs in two stages being the short-time processes controlled by the dispersive surface energy of the polymer, but the desorption rate is opposite to the base-to-acid surface energy ratio of the polymer indicating that for long-time processes the enzyme is attached to the polymer surface mainly by acid–base interactions.