MONTE-CARLO SIMULATION OF PHASE-SEPARATED SELF-ASSEMBLED FILMS

Phase-separation of self-assembled monolayer (SAM) made from binary co mponents is studied. The interaction between the molecules in the SAM films was estimated by a simple Monte Carlo simulation. The molecules are arranged on the two-dimensional triangular lattice sites and excha nge their position with the probability determined from the molecular interaction energy calculated over the Nth nearest neighbors. One-to-o ne mixture with lattice sizes of 128 x 128, 256 x 256, and 512 x 512 w as calculated, and the threshold energy for the domain formation was i ndependent of the size. On the other hand, the domain shape and size d epended on the calculation method and the lattice size. The threshold energy at 300 K corresponds to the estimated interaction between the h ydrocarbon chains of 7-8 carbon atoms. (C) 1998 Elsevier Science B.V. All rights reserved.