Ion Exchange Membrane Separators in Power Sources Sensors and Electrodes

A typical example is the use of an ion exchange membrane as a solid polyelectrolyte for a fuel cell. The composite, in which anode catalyst, poly(fluorocarbon sulfonate) cation exchange membrane and cathode catalyst are combined, has been used for hydrogen-oxygen fuel cells. The only product of this cell is water, which seems to be desirable from an ecological point of view. Methanol has also been reported for the generation of electricity and utilizable industrial chemicals by the use of a membrane-containing fuel cell. Various applications of ion exchange membranes of low electrical resistance in alkali batteries are possible. Modern cation exchange membranes made of acrylic acid grafted onto polyethylene film are widely used as separators in alkaline batteries, such as a Ni-Cd secondary battery.

Water content of the ion exchange membranes and thus their physicochemical properties changes with humidity. Therefore, ion exchange membranes are usable as a working part of a hygrometer. When water content of the membrane increases with increasing humidity, the increase in the current or ionic conductivity between the electrodes on both sides of the membrane can be measured and calibrated.

The concentration of alcohol can be indirectly determined by means of a membrane with fixed alcohol-dehydrogenase or alcohol-oxydase. It has been reported that these sensors operate accurately in acidic media after coating the enzyme-fixed membrane by a cation exchange membrane (organic acids cannot approach the enzyme membrane). A similar concept is used for constructing in vivo operating sensors for glucose presence and concentration. Some modified electrodes are constructed by coating classic electrodes with layered ion exchange materials. A typical example is the perfluorocarbon cation exchange membrane-coated electrode to control the permeability of redox species such as Ru(bpy)3Cl3 or 1,1-dihyd-roxymethylferrocene.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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