Naslov
Ex-situ measurement of charge carrier concentration in Nafion by Hall effect

Autori
Poljak, Ivan ; Županović, Paško ; Barbir, Frano

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), stručni

Izvornik
Splitech 2020 proceedings / - , 2020

Skup
5th International Conference on Smart and Sustainable Technologies (SpliTech 2020)

Mjesto i datum
Split, Hrvatska, 23.09.2020. - 26.09.2020

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Hall Effect, PEM Fuel Cells, Charge Carrier Concentration, Charge Carrier Transport

Sažetak
There is no controversy regarding the nature of charge carriers in in-situ Nafion processes, but still there is controversy regarding charge carriers in ex-situ processes. Using Hall voltage measurements, we have shown that valence electrons rather than protons are charge carriers in ex-situ processes, contrary to wide accepted assumption that protons are charge carriers in Nafion regardless of a process. Concentration of valence electrons decreases with water uptake. Yet a graph of valence electron concentration, as function of water content, is steeper than graph of inverse volume. This bring us to conclusion that total number of valence electrons decreases with a water uptake. Protons are blocked in Nafion in ex-situ measurement, since the rest of electric circuit is metal that conducts only electrons. On the other hand, in in-situ measurements electrons are blocked in Nafion due to potential barrier of dipole layer. Order of magnitude of the electron concentration we found is 10^28 m^-3.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Strojarstvo, Temeljne tehničke znanosti

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