281917 Fluctuations/Correlations in Disordered Symmetric Diblock Copolymers: Simulations and Theories

Thursday, November 1, 2012: 2:00 PM
Butler East (Westin )
Delian Yang, Jing Zong and Qiang Wang, Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO

Based on the same model system of symmetric diblock copolymers as discrete Gaussian chains interacting with soft, finite-range repulsions as commonly used in dissipative-particle dynamics simulations, we directly compare, without any parameter-fitting, the thermodynamic and structural properties of the disordered phase obtained from fast off-lattice Monte Carlo (FOMC) simulations1, reference interaction site model (RISM)2 and polymer reference interaction site model (PRISM) theories3, and Gaussian fluctuation theory. The compared quantities include the internal energy, entropy, Helmholtz free energy, pressure, constant-volume heat capacity, chain/block dimensions, and various structure factors and correlation functions in the system. Our comparisons unambiguously and quantitatively reveal the consequences of various theoretical approximations and the validity of these theories in describing the fluctuations/correlations in disordered diblock copolymers.

[1]  Q. Wang and Y. Yin, J. Chem. Phys. 130, 104903 (2009).

[2]  H. Andersen and D. ChandlerJ. Chem. Phys. 57, 1918 (1972).

[3]  K. Schweizer and J. Curro, Macromolecules 21, 3082 (1988).

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See more of this Session: Modeling and Simulation of Polymers II
See more of this Group/Topical: Materials Engineering and Sciences Division