(369d) Inverse Colloidal Crystal Membranes for Protein Ultrafiltration

Ultrafiltration (UF) is a pressure driven size-based separation process that plays a critical role in protein purification. In the biopharmaceutical industry, UF is used for protein concentration and buffer exchange. An ideal UF membrane should exhibit a narrow pore size distribution and a high porosity. Commercially available membranes do not possess both characteristics. Here we describe membranes based on inverse opal structures that we call inverted colloidal crystal (ICC) membranes. ICC membranes are ideal for UF as they display a narrow pore size distribution and a high porosity. ICC membranes with integral areas up to 500 mm2 have been fabricated in our group. Here we describe the ICC membranes we have fabricated. The ICC membranes and their colloidal crystal templates have been characterized with Scanning Electronic Microscopy and UV-Vis spectroscopy. Separation tests have been done with bovine serum albumin under different protein concentrations, pH, ionic strength and pressure. Surface modification of ICC membranes with ATRP also has been conducted to control their pore size and to improve their separation properties. The results show that ATRP is a good method for the modification of ICC membranes.