Sol−Gel Entrapment of E_T(30) in Ormosils. Interfacial Polarity−Fractality Correlation

E T (30) (2,6-diphenyl-4-(2,4,6-triphenyl- N -pyridino)phenolate) was successfully entrapped in organically modified silica (Ormosil) sol−gel matrices, while retaining its sensitivity to the environment polarity. This sensitivity was used to follow the variations in the cage interfacial polarities of the Ormosils, which were prepared from various proportions of methyltrimethoxysilane/tetramethoxysilane, and for probing the effective polarities within the pores and cages in the presence of several alkanols. Structural analysis of these Ormosils by small angle X-ray scattering revealed that these materials are surface fractals and that the surface fractality correlates linearly with the interfacial polarity of the materials. The doped sol−gel matrices are potentially suitable for alcohol sensors.