Mixed Matrix Membrane for Protein Separation

In this study, strontium-substituted nano hydroxyapatite (Sr-HAP) was synthesized by ultrasonic method. The surfaces of Sr-HAP particles were grafted with acrylic acid (AAc) by low temperature plasma technology and Sr-HAP grafted with AAc (Sr-HAP-AAc) was obtained. The dual layer polyether sulfone (PES)/HAP mixed matrix membranes (MMMs) were prepared by an immersion phase separation process. A particle free PES membrane layer was co-cast with the active support layer, which led to formation of dual layer MMMs. The active support layer consisted of Sr-HAP-AAc particles embedded in macroporous PES. The dual layer MMMs showed separation of protein via diffusion as well as adsorption. The bovine serum albumin (BSA) was used as a model protein. The BSA adsorption capacity of MMMs increased with extending equilibrium time and almost reached stable at 20 h. The BSA adsorption capacity of dual layer MMMs was 48.6 mg/(g MMMs). The dual layer MMMs with top PES layer kept good filtration and adsorption properties.