Abstract
The influence of the chemical structure of symmetrical and asymmetrical quaternary ammonium salts (QASs) on the potentiometric and impedance spectroscopic data of ion-selective poly(vinyl chloride) membranes plasticized with 2-nitrophenyl octyl ether (NPOE) and bis(2-ethylhexyl) sebacate (DOS) was investigated. It was found that the properties of the QAS, e.g. solubility in the membrane phase and, thus, the difference in the degree of association, influences the membrane characteristics. An increasing number of carbon atoms in symmetrical QASs diminishes the interference of lipophilic anions and enlarges the sensitivity to basic ones. The choice of plasticizer is important for the membrane properties as well, e.g. the influence of lipophilic ions is smaller for DOS membranes in comparison to NPOE ones. Results are discussed from the viewpoint of the difference in free enthalpy of hydration and basic properties of the anions. Additionally, the bulk properties of the membranes in dependence of QAS structure were studied by electrochemical impedance spectroscopy. The magnitude of the specific bulk resistance is governed by the dielectric properties of the plasticizer. Nevertheless, it is shown that QAS structure determines the long-term development of the bulk resistance.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
