The diagonal bond method: A new lattice polymer model for simulation study of block copolymers

Abstract

A new lattice model for Monte Carlo simulations of dense polymer melts, developed in the spirit of Verdier–Stockmayer algorithm on square and simple cubic lattices, is presented. By introducing diagonals of squares and cubes as bonds, the lattice model acquires a large number of configurations and wiggling local moves. While it maintains the excluded volume interactions of monomers, it allows bond crossings and phantom moves, which result in a high mobility of polymers. For an application, we carry out simulations of symmetric A–B block copolymer melts and observe a first-order transition. We also show the stretching of the chains, namely, the non-Gaussian character, as a function of temperature. A quicker evolution towards thermal equilibrium enables us to form an ordered tricontinuous double-diamond (OTDD) phase for linear A–B–C triblock copolymers and a new cylindrical phase for star A–B–C triblock copolymers.