“…Most commonly, Na-montmorillonite is used as the base mineral clay and its sodium cations can be exchanged with quaternary ammonium cations (Burns et al, 2006;Soule and Burns, 2001). QAC-coated montmorillonite exhibits higher zeta potential (Bate and Burns, 2010), enhanced strength, lower compressibility, and stronger retention of organic compounds (Lo, 2001;Redding et al, 2002) in the environment, yielding a variety of potential applications in waste containment, landfill liners, and slurry walls (Lorenzetti et al, 2005;Park and Jaffe, 1993;Sheng and Boyd, 1998;Smith and Jaffe, 1994). The structure of the surfactant (e.g., chain length, number of long chains, head group) and the intrinsic properties of the original clay material have a combined effect on the structure and properties of the resultant organoclay (Bergaya et al, 2006;Ha and Char, 2005;He et al, 2006;Osman et al, 2004;Xi et al, 2005aXi et al, , 2005b.…”