Haiwon Lee, L. J. Kepley, H. Hong
May 5, 1988
Citations
1
Influential Citations
196
Citations
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Journal
The Journal of Physical Chemistry
Abstract
Multilayer films of zirconium 1,10-decanediylbis(phosphonate) have been prepared on silicon and gold substrates and characterized by ellipsometry, XPS, and electrochemical measurements. The deposition technique requires first covalent attachment or adsorption of a phosphonic acid anchoring agent; HO(CH/sub 3/)/sub 2/Si(CH/sub 2/)/sub 3/PO/sub 3/H/sub 2/ (I) and (-S(CH/sub 2/)/sub 4/PO/sub 3/H/sub 2/)/sub 2/ (II) were used with Si and Au, respectively. The functionalized substrates are exposed alternately to aqueous ZrOCl/sub 2/ and 1,10-decanediylbis(phosphonic acid) solutions to yield multilayer films. Ellipsometry shows an increase in film thickness, on Si, of 17 A/layer, which corresponds to the layer spacing in bulk Zr(O/sub 3/PC/sub 10/H/sub 20/PO/sub 3/). Variable take-off angle X-ray photoelectron spectra from four-layer films have attenuated Si peaks but strong Zr and P peaks when the detector is 70/sup 0/ off the surface normal, implying that the films on Si are continuous. Electrochemical comparison of bare and functionalized Au shows facile electron transfer between Au or Au-II electrodes and 1 mM aqueous Fe(CN)/sub 6//sup 3 -/ but nearly complete blocking of electron transfer at Au-II electrodes immersed once each in ZrOCl/sub 2/ and 1,10-decanediylbis(phosphonic acid) solutions.