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Title: On the order-disorder transition of compressible diblock copolymer melts

We performed both the fast off-lattice Monte Carlo simulations of symmetric diblock copolymers (DBC) in an isothermal-isobaric ensemble and the self-consistent field calculations of asymmetric DBC to properly determine the order-disorder transition (ODT) of a model system of compressible DBC melts used in the literature when it is a first-order phase transition, and studied for the first time the co-existence of the two phases at ODT. We found that the co-existing region is quite small and decreases as the system becomes less compressible, which justifies the previous ODT results obtained by equating the Helmholtz free energy per chain of the two phases. We also found that for the most compressible system where there is no repulsion between the same type of segments, the self-consistent field theory predicts that ODT is a second-order phase transition even for asymmetric DBC melts due to its mean-field approximation.
Authors:
;  [1]
  1. Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, Colorado 80523-1370 (United States)
Publication Date:
OSTI Identifier:
22493235
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 18; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ASYMMETRY; COMPUTERIZED SIMULATION; COPOLYMERS; FREE ENERGY; MEAN-FIELD THEORY; MONTE CARLO METHOD; ORDER-DISORDER TRANSFORMATIONS; SELF-CONSISTENT FIELD; SYMMETRY