Poly(3-octylthiophene-2,5-diyl) - nanosized ruthenium dioxide composite material as solid-contact layer in polymer membrane-based K+-selective electrodes

This work presents the novel and universal approach to designing all-solid-state ISEs with PVC membrane by implementing the conducting polymer-nanoparticles of ceramic dioxide composite material as solid-contact layer. Properties of ruthenium dioxide RuO2 and poly(3-octylthiophene-2,5-diyl) (POT) were combined into one mediation layer in K+-selective electrodes what resulted in their great performance parameters. The fast and low-cost method of composite preparation and electrodes fabrication was presented in the article. The layers' microstructure, wettability and electrical parameters were studied using various methods. RuO2 particles turned out to enhance polymer's electrical and hydrophobic properties and allowed to obtain superhydrophobic layer of high electrical capacity which is favorable for solid contact. The SEM and TEM scans revealed the nano-sized particles of RuO2 contributing to the large surface area and the wettability test exposed the contact angle of 149 degrees. Electrical capacitance obtained for the RuO2-POT composite material was as high as 1.17 mF and allowed to obtain stable potentiometric response of electrodes, while the superhydrophobic properties of the layer resulted in their great performance during the water-layer test. (C) 2019 Elsevier Ltd. All rights reserved.