Block Copolymer Membranes with Artificial Free-Volume for Biofuel Production: From Synthesis to Application

Control over polymeric free-volume is key for facilitating the use of polymers in a range of technologically important applications such as energy conversion and storage, pharmaceutical purifications and biofuel production. However, controlling polymer porosity in the sub-nm level remains challenging. In this work we demonstrate a methodology that enables controlled and systematic increase of free-volume in polymeric materials. Our strategy is based on self-assembly of block copolymer/homopolymer blends to enable systematic increase of free volume in materials that are chemically identical. Furthermore, the effect of artificial free-volume on selective transport through the membranes was tested using butanol/water and ethanol/water mixtures due to their importance in biofuel production. We found that the introduction of artificial free-volume improves both alcohol permeability and selectivity. In addition to enabling rational design of better membranes, our approach provided new insight into the fundamental underpinnings of membrane transport. This seminar will discuss polymer synthesis, polymer processing and characterization as well as membrane structure-transport properties relationships.