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Anion Exchange Membrane
An anion exchange membrane (AEM) is a semipermeable membrane generally made from ionomers and designed to conduct anions but reject gases such as oxygen or hydrogen. Applications Anion exchange membranes are used in electrolytic cells and fuel cells to separate reactants present around the two electrodes while transporting the anions essential for the cell operation. An important example is the hydroxide anion exchange membrane used to separate the electrodes of a direct methanol fuel cell (DMFC) or direct-ethanol fuel cell (DEFC). Poly(fluorenyl-co-aryl piperidinium) (PFAP)-based anion exchange materials (electrolyte membrane and electrode binder) with high ion conductivity and durability under alkaline conditions has been demonstrated for use to extract hydrogen from water. Performance was 7.68 A/cm2, some 6x the performance of existing materials. Its yield is about 1.2 times that of commercial proton exchange membrane technology (6 A/cm2), and it does not require the use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semipermeable Membrane
Semipermeable membrane is a type of biological or synthetic, polymeric membrane that will allow certain molecules or ions to pass through it by osmosis. The rate of passage depends on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute. Depending on the membrane and the solute, permeability may depend on solute size, solubility, properties, or chemistry. How the membrane is constructed to be selective in its permeability will determine the rate and the permeability. Many natural and synthetic materials which are rather thick are also semipermeable. One example of this is the thin film on the inside of the egg. Biological membranes are selectively permeable, with the passage of molecules controlled by facilitated diffusion, passive transport or active transport regulated by proteins embedded in the membrane. Biological membranes An example of a biological semi-permeable membrane i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |