Impedance spectroscopic study on single-piece all-solid-state calcium-selective electrode based on polyaniline

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Publikationens författare: Tom Lindfors, Johan Bobacka, Andrzej Lewenstam, Ari Ivaska
Förläggare: ROYAL SOC CHEMISTRY
Publiceringsår: 1996
Tidskrift: Analyst
Tidskriftsakronym: ANALYST
Volym: 121
Nummer: 12
Artikelns första sida, sidnummer: 1823
Artikelns sista sida, sidnummer: 1827
Antal sidor: 5
ISSN: 0003-2654
eISSN: 1364-5528


Abstrakt

Single-piece all-solid-state calcium-selective electrodes (CaSPEs) have been studied with impedance spectroscopy. The molar ratio (y) of the protonic acid, bis(2-ethylhexyl)hydrogenphosphate, to a repeat unit of polyaniline (PANI) was y = 0.50. The protonation was performed both at 25 and 110 degrees C. Impedance measurements were used to study the electronic and ionic processes in the CaSPE membranes, The results were compared with a calcium coated-wire ion-selective electrode (CaCWE). The bulk resistance of the CaSPEs decreases with PANI concentrations up to 10% (m/m), owing to improved ionic mobility in the CaSPE membranes. The charge transfer at the substrate/membrane interface was found to be facilitated by incorporation of PAM in the electrode matrix, PAM also stabilizes the bulk resistance of the CaSPEs compared to the CaCWE. Two types of membranes were studied: (i) 'wet' membranes that had been in contact with an aqueous 0.1 mol dm(-3) CaCl2 solution and (ii) 'dry' membranes. The obtained impedance spectra were fitted to equivalent circuits describing the CaSPE system.


Nyckelord

impedance spectroscopy, polyaniline, single-piece calcium-selective electrode

Senast uppdaterad 2019-20-10 vid 04:50