Bio-Inspired Copolymer Membranes for Direct Methanol Fuel Cells

Implementation of new technologies for soldier survivability often requires lightweight and reliable power sources. Direct-Methanol Fuel Cells (DMFCs) are attractive both in military and consumer electronics applications where their energy density, power output, and lifetime make them ideally suited to address weight and power limitations. DMFCs have been slow to materialize especially due to drastic reduction in fuel efficiency caused by membranes with high methanol permeability. A novel approach to design a new generation of membranes is much needed to overcome the current drawbacks. This program proposes to develop a novel biomimetic composite membrane consisted of block copolymer vesicles functionalized with biological transmembrane proteins such as gramicidin-A. When hosted within a mechanically stable secondary support structure, these membranes are expected to exhibit high proton conductivity and reduced methanol permeability due to the highly selective protein channels formed and aligned within polymer vesicles. The stability and functionality of polymer vesicles will be investigated at methanol concentrations as high as 15M. As a proof-of-concept, the DMFC performance of optimized membranes will also be evaluated using an air-breathing, single cell configuration. The unique processing method combined with the judicious selection of vesicle/protein pairs will make this bio-inspired membrane an attractive component for DMFCs.