title: Synchrotron radiation/Fourier transform-infrared microspectroscopy study of undesirable water inclusions in solid-contact polymeric ion-selective electrodes.
abstract: This paper reports on three-dimensional synchrotron radiation/Fourier transform-infrared microspectroscopy (SR/FT-IRM) imaging studies of water inclusions at the buried interface of solid-contact-ion-selective electrodes (SC-ISEs). It is our intention to describe a nondestructive method that may be used in surface studies of the buried interfaces of materials, especially multilayers of polymers. Herein, we demonstrate the power of SR/FT-IRM for studying water inclusions at the buried interfaces of SC-ISEs. A poly(methyl methacrylate)-poly(decyl methacyrlate) [PMMA-PDMA] copolymer revealed the presence of micrometer sized inclusions of water at the gold/membrane interface, while a coupling of a hydrophobic solid contact of poly(3-octylthiophene 2,5-diyl) (POT) prevented the accumulation of water at the buried interface. A similar study with a poly (3,4-ethylenedioxythiophene)/poly (styrenesulfonate) [PEDOT/PSS] solid contact also revealed an absence of distinct micrometer-sized pools of water; however, there were signs of absorption of water accompanied by swelling of the PEDOT/PSS underlayer, and these membrane zones are enriched with respect to water.
authors.affiliation: Department of Chemistry, Nanochemistry Research Institute, Curtin University of Technology, GPO Box U1987, Perth, Western Australia, 6845, Australia.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Veder
authors.forename: Kunal
authors.initials: K
authors.lastname: Patel
authors.forename: Graeme
authors.initials: G
authors.lastname: Clarke
authors.forename: Ewa
authors.initials: E
authors.lastname: Grygolowicz-Pawlak
authors.forename: Debbie S
authors.initials: DS
authors.lastname: Silvester
authors.forename: Roland
authors.initials: R
authors.lastname: De Marco
authors.forename: Ernö
authors.initials: E
authors.lastname: Pretsch
authors.forename: Eric
authors.initials: E
authors.lastname: Bakker
mesh_terms: D006046:Gold / Q000737:chemistry; D017736:Ion-Selective Electrodes; D011108:Polymers / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D017356:Synchrotrons; D013876:Thiophenes / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D011108:Polymers; D013876:Thiophenes; C088351:poly(3-octylthiophene); D014867:Water; D006046:Gold