Monte Carlo phase diagram for diblock copolymer melts

Eur Phys J E Soft Matter. 2010 Jul;32(3):255-64. doi: 10.1140/epje/i2010-10651-x. Epub 2010 Jul 28.

Abstract

The phase diagram for diblock copolymer melts is evaluated from lattice-based Monte Carlo simulations using parallel tempering, improving upon earlier simulations that used sequential temperature scans. This new approach locates the order-disorder transition (ODT) far more accurately by the occurrence of a sharp spike in the heat capacity. The present study also performs a more thorough investigation of finite-size effects, which reveals that the gyroid (G) morphology spontaneously forms in place of the perforated-lamellar (PL) phase identified in the earlier study. Nevertheless, there still remains a small region where the PL phase appears to be stable. Interestingly, the lamellar (L) phase next to this region exhibits a small population of transient perforations, which may explain previous scattering experiments suggesting a modulated-lamellar (ML) phase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Computer Simulation
  • Models, Chemical
  • Models, Statistical
  • Monte Carlo Method*
  • Phase Transition*
  • Polymers / chemistry*
  • Temperature

Substances

  • Polymers