Effect of surfactant C12TMA molecules on the self-association of R6G dye in thin films of laponite clay

The effect of the surfactant dodecyltrimethyl ammonium (C12TMA) molecules on the aggregation of rhodamine 6G (R6G) laser dye intercalated in the interlayer space of clay laponite (Lap) thin films is studied by absorption and fluorescence spectroscopies. The presence of C12TMA molecules reduces in nearly one order of magnitude the tendency of the dye molecules to self-associate. Moreover, the organophilic environment created by the surfactant molecules promotes the formation of fluorescent J-type R6G aggregates with respect to those aggregates formed in pure Lap films with a hydrophilic ambience. Consequently, the fluorescence ability of dye/clay systems is improved by the presence of surfactant molecules, mainly in those samples with moderate/high dye loadings.