Functionalization of Cloisite 30B with fluorescent dyes

An organo-montmorillonite (Cloisite® 30B) was modified with fluorescent dyes to obtain photo-functional inorganic–organic complexes for real-time monitoring of polymer-clay nanocomposite processing. The photo-functionalization with 9-anthracenemethanol (anth) was tested using adsorption from solution, as well as dry and melt compounding. Rhodamine 6G Perchlorate (RhP) and Nile Blue A Perchlorate (NBAP) were adsorbed by cation exchange. XRD, TGA and spectrofluorimetry showed that cation exchange in water/ethanol at 80 °C, with an added amount of RhP corresponding to 25% of the initial surfactant content, followed by washing, recovering and drying, yielded the best results. The intercalation of the fluorescent dyes rearranged the paraffinic structure of the surfactant molecules by increasing the tilting angle from 37° to 49°.

Research Highlights
► Organo-clay minerals can be photo-functionalized by cation exchange.
► Small amounts of dyes are sufficient to render organo-clay minerals photo-active.
► The intercalation of small dye molecules rearrange the paraffinic configuration.
► Results depend on molecular dimension, configuration and volume of the dye.
► No fluorescence quenching is observed for intercalated dyes.