Enhanced Electrochemical Performance of Poly(aniline) Solid-Contact pH Electrodes Based on Alkyldibenzylamine

Abstract

Hydrogen ion-selective solid-contact electrodes based on alkyldibenzylamine (alkyl=butyl, hexyl, octyl, decyl, dodecyl) have been prepared. Solid-contact electrodes have been fabricated from polymer cocktail solutions based on alkyldibenzylamine. We have shown that the response ranges and Nernstian slopes are influenced by the alkyl chain length. Especially, solid-contact electrodes with decyldibenzylamine have shown the best selectivity, reproducibility of e.m.f. and long-term stability. Solid-contact electrodes containing decyldibenzylamine were shown to be linearly selective to hydrogen ion in the range of pH 2.1 - 12.4; their Nernstian slopes were 52.9 mV/pH at 20 ± 0.2°C. This electrode, coated with PVC containing decyldibenzylamine neutral carrier, showed no redox response in comparison with an uncoated Pt electrode and a poly(aniline)-coated Pt electrode. The 90% response time was less than 5 s, and their electrical resistance varied in the range of 0.1 - 2.0 MΩ.