Photophysical Probe Study of Alkylammonium-Montmorillonites

Intercalation of anthracene and pyrene into two types of alkylammonium-montmorillonites (octade-cyltrimethylammonium and dioctadecyldimethylammonium types) is carried out by solid-solid reactions which we have developed recently. The arene molecules are solubilized at extremely high concentrations in the two-dimensional interlayer spaces of the alkylammonium-montmorillonites with retaining the ordered structure. Fluorescence spectra of the intercalated arenes show that two different types of adsorption occurred. The arenes in the octadecyltrimethylammonium-montmorillonite are aggregated and those in the dimethyldioctadecylammonium-montmorillonite are rather dispersed between the alkyl chains in the interlayer spaces. The alkylammonium-montmorillonites are novel two-dimensional media to organize poorly water soluble species.