Back Membrana d'intercanvi de protons Catalan Protonen-Austausch-Membran German Membrana de intercambio de protones Spanish Membrane échangeuse de protons French Membran penukar proton ID Membrana a scambio protonico Italian イオン交換膜 Japanese Proton-utvekslingsmembran NB Membrană schimbătoare de protoni Romanian Протонообменная мембрана Russian
A proton-exchange membrane, or polymer-electrolyte membrane (PEM), is a semipermeable membrane generally made from ionomers and designed to conduct protons while acting as an electronic insulator and reactant barrier, e.g. to oxygen and hydrogen gas.[1] This is their essential function when incorporated into a membrane electrode assembly (MEA) of a proton-exchange membrane fuel cell or of a proton-exchange membrane electrolyser: separation of reactants and transport of protons while blocking a direct electronic pathway through the membrane.
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 the fluoropolymer (PFSA)[2] Nafion, a DuPont product.[3] While Nafion is an ionomer with a perfluorinated backbone like Teflon,[4] 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.[5]
PEM fuel cells use a solid polymer membrane (a thin plastic film) which is permeable to protons when it is saturated with water, but it does not conduct electrons.
- ^ Alternative electrochemical systems for ozonation of water. NASA Tech Briefs (Technical report). NASA. 20 March 2007. MSC-23045. Retrieved 17 January 2015.
- ^ Zhiwei Yang; et al. (2004). "Novel inorganic/organic hybrid electrolyte membranes" (PDF). Prepr. Pap.-Am. Chem. Soc., Div. Fuel Chem. 49 (2): 599.
- ^ US patent 5266421, Townsend, Carl W. & Naselow, Arthur B., "Enhanced membrane-electrode interface", issued 2008-11-30, assigned to Hughes Aircraft
- ^ Gabriel Gache (17 December 2007). "New Proton Exchange Membrane Developed – Nafion promises inexpensive fuel-cells". Softpedia. Retrieved 18 July 2008.
- ^ Nakhiah Goulbourne. "Research Topics for Materials and Processes for PEM Fuel Cells REU for 2008". Virginia Tech. Archived from the original on 27 February 2009. Retrieved 18 July 2008.