Journal of Chemical Physics, Vol.108, No.17, 7410-7415, 1998
Molecular dynamics simulations of organically modified layered silicates
Molecular dynamics (MD) simulations are used to study the static and dynamic properties of 2:1 layered silicates ion exchanged with alkyl-ammonium surfactants. These systems are in the form of oligomeric alkanes grafted by cationic groups on atomically smooth crystalline layers 10 Angstrom thick and several microns wide. The organically modified layers self-assemble parallel to each other to form alternating, well-ordered organic/inorganic multilayers. By studying the systems at the experimentally measured layer separations, computer modeling directly provides the structure and dynamics of the intercalated surfactant molecules. The grafted-chain conformations are also expressed through the trans-gauche conformer radios and transition frequencies which compare well with Fourier transform infrared spectroscopy (FTIR) experiments.
Keywords:SOLID-SURFACES;N-OCTANE;FORCE MEASUREMENTS;LIQUID;ALKANES;FILMS;INTERFACES;TRANSITION;RELAXATION;SHEAR