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The chemically resistant (but expensive) fluorinated ionomers are used as electrochemical cell membranes, of which the first and most prominent example is Nafion. Developed in the 1960s, it was initially deployed as fuel cell material in spacecraft and then replaced mercury-based chloralkali process cells.
This effect often increases a drug's bioavailability because of increased cell membrane penetration. [14] Although the potential of fluorine being released in a fluoride leaving group depends on its position in the molecule, [15] organofluorides are generally very stable, since the carbon–fluorine bond is strong.
An improved generation of General Electric's PEM fuel cell was used in all subsequent Gemini missions, but was abandoned for the subsequent Apollo missions. [9] The fluorinated ionomer Nafion, which is today the most widely utilized proton-exchange membrane material, was developed by DuPont plastics chemist Walther Grot. Grot also demonstrated ...
Solid Polymer Electrolytes, which are made by connecting or depositing electrodes (usually noble metal) to both sides of the membrane, conduct the electrons through an energy requiring process and rejoin the hydrogen ions to react with oxygen and produce water. [3] Fuel cells are expected to find strong use in the transportation industry.
Fluorinated compounds often display distinct solubility properties. ... nafion is a solid acid that is used as the membrane in most low temperature fuel cells.
Fluorinated polymers like PTFE and PVDF are especially thermally stable due to strong carbon-fluorine (C–F) bonds, the strongest in organic chemistry, which contribute to the durability of these materials under heat. PVDF is semi-crystalline, giving it a balance of rigidity and flexibility across temperatures from −35 °C to 160 °C.
Fluorinated ethylene propylene (FEP) is the second most produced fluoropolymer. Films from two fluoropolymers serve as glass-replacements in solar cells. [17] [19] [20] Fluorinated ionomers (polymers that include charged fragments) are expensive, chemically resistant materials used as membranes in certain electrochemical cells.
Cross-sectional view of the structures that can be formed by phospholipids in an aqueous solution. A biological membrane, biomembrane or cell membrane is a selectively permeable membrane that separates the interior of a cell from the external environment or creates intracellular compartments by serving as a boundary between one part of the cell and another.