Sonication assisted growth of fluorophosphate films on alumina surfaces

We present a spectroscopic and morphological study of the deposition of mono-, di-, and triester fluorophosphate films on alumina surfaces. Solid-state NMR and Fourier transform infrared characterization of the films show that species capable of forming three P-O-Al linkages are favored over mono- and bidentate binding moieties during the adsorption process. Our results indicate that film formation in conjunction with local sonication greatly enhances the resulting film density and homogeneity by removing weakly bound species and overcoming the influence of the autophobic properties of the adsorbates. This in turn leads to uniform films of tridentate bonded species that exhibit remarkable environmental stability in the presence of refluxing water.