Synchrotron Radiation/Fourier Transform-Infrared Microspectroscopy Study of Undesirable Water Inclusions in Solid-Contact Polymeric Ion-Selective Electrodes

摘要

This paper reports on three-dimensional synchrotronnradiation/Fourier transform-infrared microspectroscopyn(SR/FT-IRM) imaging studies of water inclusions at thenburied interface of solid-contact-ion-selective electrodesn(SC-ISEs). It is our intention to describe a nondestructivenmethod that may be used in surface studies of the buriedninterfaces of materials, especially multilayers of polymers.nHerein, we demonstrate the power of SR/FT-IRM fornstudying water inclusions at the buried interfaces of SCISEs.nA poly(methyl methacrylate)-poly(decyl methacyrlate)n[PMMA-PDMA] copolymer revealed the presencenof micrometer sized inclusions of water at the goldmembrane interface, while a coupling of a hydrophobicnsolid contact of poly(3-octylthiophene 2,5-diyl) (POT)nprevented the accumulation of water at the buried interface.nA similar study with a poly (3,4-ethylenedioxythiophene)poly (styrenesulfonate) [PEDOT/PSS] solid contactnalso revealed an absence of distinct micrometer-sizednpools of water; however, there were signs of absorptionnof water accompanied by swelling of the PEDOT/PSSnunderlayer, and these membrane zones are enriched withnrespect to water.