The ordering of symmetric diblock copolymers: A comparison of self-consistent-field and density functional approaches

Journal Article · Sat Feb 01 00:00:00 EST 1997 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.473332· OSTI ID:463522

Nath, S K; McCoy, J D ^[1]; Curro, J G; Saunders, R S ^[2]

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1. Department of Materials and Metallurgical Engineering New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801 (United States)
2. Sandia National Laboratories Albuquerque, New Mexico 87185 (United States)

Polymer reference interaction site model (PRISM) based density functional (DF) theory is used to evaluate the structure and thermodynamics of structurally symmetric, freely jointed, diblock chains with 0.50 volume fraction. These results are compared to the results of self-consistent-field (SCF) theory. Agreement between the predictions of the SCF and DF theories is found for the lamella spacing well above the order{endash}disorder transition (ODT) and for the qualitative behavior of the interfacial thickness as a function of both chain length and Flory{endash}Huggins {chi} parameter. Disagreement is found for the magnitude of the interfacial thickness where DF theory indicates that the thickness is 1.7{plus_minus}0.2 times larger than that predicted by SCF theory. It appears that behavior on the monomer length scale is sensitive to system specific details which are neglected by SCF theory. {copyright} {ital 1997 American Institute of Physics.}

• Research Organization: Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 463522
• Journal Information: Journal of Chemical Physics, Vol. 106, Issue 5; Other Information: PBD: Feb 1997
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
COPOLYMERS
THERMODYNAMICS
MOLECULAR STRUCTURE
THERMODYNAMIC PROPERTIES
ORDER-DISORDER TRANSFORMATIONS
FUNCTIONAL ANALYSIS
INTERFACES
SELF-CONSISTENT FIELD