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Potassium-Selective Electrodes with Stable and Geometrically Well-Defined Internal Solid Contact Based on Nanoparticles of Polyaniline and Plasticized Poly(vinyl chloride)

“…In this paper, the internal SC is prepared according to the SPE concept 26 by using an organic dispersion of PANI nanoparticles with a mean particle size of 8 nm. Similar concepts utilizing PANI(DiOHP) and POT were quite recently introduced by Mihkelson et al ,, and Maj-Żurawska et al , In these concepts, the CP is dispersed within the plasticized PVC membrane. This work focuses on the long-term stability of PANI nanoparticles used in the internal SC, the preparation of geometrically well-defined contacts containing 2−20% (m/m) PANI, and the applicability of an organic PANI dispersion as a SC component.…”

“…The pH stability of PANI is of crucial importance when applying PANI as a component in all-solid-state ion-selective electrodes (ISEs). Surprisingly, the stability of the solid contact (SC) layer of PANI is reported in only one study, although different types of electrochemically prepared − and soluble forms of PANI − have been applied as SC materials 15-25 and in the single-piece (SPE) configuration. − ,− No stability studies have either been carried out with the other types of most commonly used CP-based SC materials, such as poly(pyrrole), poly(3-octylthiophene) (POT), and poly(3,4-ethylenedioxythiophene) (PEDOT). In most of the studies, it is only assumed that the CP-based SCs are stable, even though it is known that time-dependent changes of the oxidation state may occur within the CP phase.…”

“…In comparison to electrochemically polymerized CPs, the contacts prepared from soluble CPs or organic dispersions are usually easily soluble in the outer ion-selective membrane (ISM). This is the case with PANI dissolved with dodecylbenzenesulfonic acid (DBSA) and bis(2-ethylhexyl)phosphoric acid (DiOHP), PANI(DiOHP) (used in refs , , and 34), and POT, which is soluble in most organic solvents. It is therefore difficult to prepare geometrically well-defined SCs in a reproducible manner.…”

Stability of the Inner Polyaniline Solid Contact Layer in All-Solid-State K+-Selective Electrodes Based on Plasticized Poly(vinyl chloride)

“…The most common solid contact materials are polypyrrole (PPy), ,− polyaniline (PANI), − poly(3,4-ethylenedioxythiophene) (PEDOT), − and polythiophene derivatives, e.g., poly(3-octylthiophene) (POT). − They are usually electrochemically deposited on electrically conducting substrates (Au, Pt, or glassy carbon, GC) from aqueous solutions, although there are a few exceptions where organic solvents 18,35,37 or soluble CPs (PANI and POT) 24,27,36,38 have been used for the deposition of the inner solid contact layer. Water will always be present at the ISM|CP and CP|substrate interfaces after depositing the inner SC layer from aqueous solutions.…”