Adsorption of protein onto double layer mixed matrix membranes

This work proposed a novel approach for protein purification by using double layer mixed matrix membranes (MMMs). The double layer MMMs consisting of an active support and separating layer were prepared by co-casting two polymer solutions onto a glass plate. The active support layer consisted of nano hydroxyapatite (HAP) particles embedded in macroporous polyether sulfone (PES) and the separating layer was particle free PES membrane. The influence of separating layer with different PES content on membrane morphology was studied. The double layer MMMs were further characterized concerning permeability and adsorption capacity. The double layer MMMs showed purification of protein via diffusion as well as adsorption. The bovine serum albumin (BSA) was used as a model protein. The properties and structures of double layer MMMs prepared by immersion phase separation process were characterized by pure water flux, BSA adsorption and scanning electron microscopy (SEM).