Proton exchange membrane

Proton exchange membrane

A proton exchange membrane or polymer electrolyte membrane (PEM) is a semipermeable membrane generally made from ionomers and designed to conduct protons while being impermeable to gases such as oxygen or hydrogen.cite web |url= |title=Alternative electrochemical systems for ozonation of water |accessdate=2008-07-18 |author= |date=2003-07 |publisher=NASA Tech Briefs] This is their essential function when incorporated into a membrane electrode assembly (MEA) of a proton exchange membrane fuel cell: separation of reactants and transport of protons. PEMs can be made from either pure polymer membranes or from composite membranes where other materials are embedded in a polymer matrix. One of the most common and commercially available PEM materials is Nafion, a DuPont product.Ref patent|country=US|number=5266421|status=patent|title=US Patent 5266421 - Enhanced membrane-electrode interface|pubdate=|gdate=2008-11-30|fdate=1992-05-12|pridate=|invent1=Townsend, Carl W.|invent2=Naselow, Arthur B.|assign1=Hughes Aircraft|assign2=|class=H01M8/10B2] While Nafion is an ionomer with a perfluorinated backbone like Teflon,cite web |url= |title=New Proton Exchange Membrane Developed - Nafion promises inexpensive fuel-cells |accessdate=2008-07-18 |author=Gabriel Gache |date=2007-12-17 |work= |publisher=Softpedia] there are many other structural motifs used to make ionomers for proton exchange membranes. Many use polyaromatic polymers while others use partially fluorinated polymers.

Proton exchange membranes are primarily characterized by proton conductivity (σ), methanol permeability (P), and thermal stability.cite web |url= |title=Research Topics for Materials and Processes for PEM Fuel Cells REU for 2008 |accessdate=2008-07-18 |author=Nakhiah Goulbourne|publisher=Virginia Tech]


ee also

*Artificial membrane
*Electroosmotic pump

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Proton Exchange Membrane — Eine Protonen Austausch Membran, häufig auch Proton Exchange Membrane (PEM) oder Polymer Electrolyte Membrane (PEM) genannt, ist eine im Allgemeinen aus Ionomer hergestellte semipermeable Membran. PEMs sind für Protonen durchlässig, während der… …   Deutsch Wikipedia

  • proton exchange membrane — noun a membrane forming a barrier in a hydrogen fuel cell through which the hydrogen ions created in oxidation migrate to join with the oxygen ions on the cathode side to form water. Also, PEM …   Australian English dictionary

  • Proton exchange membrane fuel cell — Diagram of a PEM fuel cell Proton exchange membrane fuel cells, also known as polymer electrolyte membrane (PEM) fuel cells (PEMFC), are a type of fuel cell being developed for transport applications as well as for stationary fuel cell… …   Wikipedia

  • Proton Exchange Membrane Fuel Cell — Die Polymerelektrolytbrennstoffzelle (engl. Polymer Electrolyte Fuel Cell, PEFC, auch Protonenaustauschmembran Brennstoffzelle, engl. Proton Exchange Membrane Fuel Cell, PEMFC oder Feststoffpolymer Brennstoffzelle, engl. Solid Polymer Fuel Cell,… …   Deutsch Wikipedia

  • proton exchange membrane fuel cell — noun a fuel cell operating at a relatively low temperature, which uses a proton exchange membrane …   Australian English dictionary

  • Proton conductor — A proton conductor is an electrolyte, typically a solid electrolyte, in which movable hydrogen ions (protons) are the primary charge carriers.CompositionProton conductors are usually composed of polymer or ceramic because the pore size is small… …   Wikipedia

  • Membrane electrode assembly — A membrane electrode assembly (MEA) is an assembled stack of proton exchange membranes (PEMs) or alkali anion exchange membrane (AAEMs), catalyst and flat plate electrode used in a fuel cell[1]. Contents 1 PEM MEA 2 Research 3 See als …   Wikipedia

  • Membrane échangeuse de protons — Une membrane échangeuse de protons ou membrane à électrolyte polymère (PEM) est une membrane semi perméable fabriquée à partir d’ionomères permettant la conduction protonique tout en étant imperméable aux gaz tels que le dioxygène ou le… …   Wikipédia en Français

  • Pile a combustible a membrane d'echange de protons — Pile à combustible à membrane d échange de protons Diagramme d une PEMFC. Les piles à combustible à membrane d échange de protons, connues aussi sous le nom de piles à combustible à membrane électrolyte polymère (ou PEMFC selon l acronyme des… …   Wikipédia en Français

  • Pile à combustible à membrane d'échange de protons — Diagramme d une PEMFC. Les piles à combustible à membrane d échange de protons, connues aussi sous le nom de piles à combustible à membrane électrolyte polymère (ou PEMFC selon l acronyme des expressions anglaises proton exchange membrane fuel… …   Wikipédia en Français