| Popis: |
Bilayer lipid membranes are a necessary component of all life and have been examined for use in novel applications such as biosensors and polymer electrolyte membrane fuel cells. The goal of this study was to produce stabilized phospholipid bilayer membranes with gramicidin channels within the pores of porous polycarbonate “scaffolds” in order to improve the functional lifetime of the membranes. 1-Palmitoyl-2-10,12 Tricosadiynoyl-sn-Glycero-3-Phosphocholine (PTPC) and 1-Palmitoyl-2-10,12 Tricosadiynoyl-sn-Glycero-3-Phosphoethanolamine (PTPE) were utilized to develop polymerized phospholipid bilayers. The bilayer lipid membranes were formed by depositing a solution of lipids in decane onto a porous polycarbonate filter. An aqueous medium was then deposited on each side of the polycarbonate filter so that self-assembly of the bilayer lipid membrane could occur. The membranes were photopolymerized using short-wavelength ultraviolet radiation (λ = 254 nm).The resulting membranes were chemically analyzed using UV-Visual Spectroscopy and Raman Spectroscopy. The stability of membranes with and without gramicidin channels at elevated temperatures (60 - 80 °C) was analyzed by measuring the resistance or current across the phospholipid bilayer / polycarbonate membrane system. Resistance values in the giga-ohm range were found for phospholipid bilayer membranes without gramicidin in the presence of potassium, calcium or N-methyl-D-glucamine ions at 60 °C. When gramicidin channels were incorporated into the phospholipid bilayer membranes, the resistance values dropped to the order of mega-ohms. Additionally, these membranes were used to make novel proton exchange membrane fuel cells (PEM fuel cells). This study showed that gramicidin could be inserted into photopolymerized phospholipid bilayers and remained functional at 60 °C. It also showed that it might be possible to produce novel PEM fuel cells using these polymerized phospholipid bilayer membranes as proton exchange membranes. |
