@article {Zazoua:2009:1546-198X:995,
title = "Characterisation of a Cr(VI) Sensitive Polysiloxane Membrane by X-ray Photoelectron Spectrometry and Atomic Force Microscopy",
journal = "Sensor Letters",
parent_itemid = "infobike://asp/senlet",
publishercode ="asp",
year = "2009",
volume = "7",
number = "5",
publication date ="2009-10-01T00:00:00",
pages = "995-1000",
itemtype = "ARTICLE",
issn = "1546-198X",
eissn = "1546-1971",
url = "https://www.ingentaconnect.com/content/asp/senlet/2009/00000007/00000005/art00064",
doi = "doi:10.1166/sl.2009.1187",
keyword = "POLYSILOXANE MEMBRANE, XPS, AFM, ELECTROLYTE/MEMBRANE/INSULATOR/SEMICONDUCTOR STRUCTURES",
author = "Zazoua, A. and Kherrat, R. and Caballero, D. and Errachid, A. and Jaffrezic-Renault, N. and Bessueille, F. and L{\’e}onard, D.",
abstract = "Cr(VI) sensitive polysiloxane membranes containing tributylphosphate (TBP) or trioctylphosphine oxide (TOPO) were characterized in this study. TBP and TOPO as carriers, have a high selectivity for Cr(VI). The potentiometric response of EMIS (Electrolyte/Membrane/Insulator/Semiconductor)
sensors presents a quasi-nernstian response for Cr2O2
7 exchange. The ion exchange is shown by X-ray photoelectron spectrometry (XPS), the binding energy of the Cr 2p1/2 peak corresponding to Cr(VI) and the atomic composition after exposure to Cr(VI)
shows a factor 1.7 higher for siloprene-TBP membrane. The conformational topography of both polymeric membranes was characterized by Atomic Force Microscopy (AFM), the exchange of Cr(VI) leading to a heterogeneous topographic state. Adhesion force measurements are also performed to study the
properties of adhesion of both selective membranes with a non-functionalized Si AFM tip and with an OTS functionalized one to study the interactions between the tip and the membrane, in liquid before and after the exposure of the membrane to ion chromium. The presence of the ionophores does
not practically change the adhesion force compared to pure polysiloxane, showing a good solubility of the ionophore and the orientation of the alkyl chains towards the polysiloxane surface. After the exchange with Cr(VI), the adhesion force decreases drastically due to the hydrophilic character
of the surface, complex of Cr(VI) with the PO groups of both ionophore being oriented towards the surface.",
}