“…The ion-ion interaction among molecules of cationic dye and the negative surface charge of montmorillonite layers represents a very strong non-covalent interaction. Clearly, the adsorption of organic cationic species is an experimentally straightforward task (Janek and Lagaly, 2003;Bujdák and Iyi, 2008). Nevertheless, the high local charge density distribution, including domain areas existing on the clay mineral surface, is the greatest obstacle to control formation of desired dye aggregates for 2D surface functionalization (Lagaly and Weiss, 1975;Ogawa et al, 1996;Janek et al, 1997;Bujdák et al, 2001).…”