Controlled microstructures of amphiphilic cationic azobenzene-montmorillonite intercalation compounds

The intercalation of two amphiphilic cationic azobenzene derivatives into the interlayer space of montmorillonite has been conducted by the ion exchange reactions between sodium montmorillonite and p-(ω-trimethylammoniopentyloxy)-p′-(dodecyloxy)azobenzene bromide or p-(ω-trimethylammoniodecyloxy)-p′-(octyloxy)azobenzene bromide. X-Ray diffraction and elemental analysis results indicated that the dye cations were intercalated into the interlayer space of montmorillonite. The spectral properties as well as the X-ray diffraction results have revealed that the adsorbed azo dye cations form so-called J-like aggregates with mono- and bi-layers in the interlayer space of montmorillonite. The orientation of the chromophore was controlled by host-guest and guest-guest interactions. The intercalated azo dyes exhibit reversible trans-cis photoisomerization by UV and visible light irradiation.