Abstract
A partial phase diagram is constructed for diblock copolymer melts using lattice-based Monte Carlo simulations. This is done by locating the order-disorder transition (ODT) with the aid of a recently proposed order parameter and identifying the ordered phase over a wide range of copolymer compositions (0.2≤f≤0.8). Consistent with experiments, the disordered phase is found to exhibit direct first-order transitions to each of the ordered morphologies. This includes the spontaneous formation of a perforated-lamellar phase, which presumably forms in place of the gyroid morphology due to finite-size and/or nonequilibrium effects. Also included in our study is a detailed examination of disordered cylinder-forming (f=0.3) diblock copolymers, revealing a substantial degree of pretransitional chain stretching and short-range order that set in well before the ODT, as observed previously in analogous studies on lamellar-forming (f=0.5) molecules.
Original language | English (US) |
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Article number | 024904 |
Journal | Journal of Chemical Physics |
Volume | 124 |
Issue number | 2 |
DOIs | |
State | Published - 2006 |
Externally published | Yes |
ASJC Scopus subject areas
- General Physics and Astronomy
- Physical and Theoretical Chemistry