New organo-montmorillonite complexes with hydrophobic and hydrophilic functions

Quaternary alkylammonium cations (R4N+) with different molecular structures were intercalated into layered aluminosilicate, Na+-montmorillonite (M), by ion exchange reaction. Four kinds of R4N+ molecular ions, [(CH3(CH2)(17))(x)N(CH3)(4-x)](+) with x = 1 (ODTM) and x = 2 (DMDS) and [(CH3(CH2)(15)COO(CH2)(2))(x)N(CH3)(CH2CH2OH)(3-x)](+) with x = 1 (DHMC) and x = 2 (DCEM), were used as intercalants. The relative dispersibility of intercalated R4N+M samples in polar and nonpolar solvents were evaluated on the basis of viscosity. Even in an aqueous solution, the DHMC-M and DCEM-M complexes, exhibited good dispersibility due to the hydrophilic functional groups in the organic cations. On the other hand, the DMDS-M and ODTM-M complexes containing only aliphatic long chain showed enhanced dispersibility in nonpolar solvents like n-hexane. (C) 1997 Elsevier Science B.V.