Document Type
Article
Publication Date
1993
Abstract
We calculate the lamellar period L and interphase thickness a of an incompressible melt of symmetric diblock copolymers from the onset of phase segregation (weak segregation limit) to the limit where segregation is almost complete (strong segregation limit) by numerically solving a mean field lattice model, where the lattice spacing is taken small enough to approximate a continuum. Our results for L and a agree with previously derived theoretical formulas in both limits. Based on the first few terms of a Fourier series expansion of the density profile, we show analytically that L = 0.844R(ÇN)0.571 at the weak segregation limit, where R is the unperturbed molecular radius of gyration, Ç the Flory interaction parameter, and N the number of statistical segments per molecule; the compressibility of the melt - even in the incompressible limit - must be taken into consideration to get the correct dependence of L on ÇN, and the Fourier series approximation turns out to be accurate over a very small range of ÇN.
Keywords
calculations, compressibility, crystal lattices, mathematical models, physical chemistry, structure (composition), lamellar ordering, lattice spacing, mean field theory, statistical segments, symmetric diblock copolymers, block copolymers
Publication Title
Macromolecules
Rights
© 1993 American Chemical Society. Reprinted (adapted) with permission from Macromolecules 26:13, 3344-3350.
Recommended Citation
R. A. Sones, E. M. Terentjev, and R. G. Petschek. Lamellar ordering in symmetric diblock copolymers. Macromolecules 1993 26 (13), 3344-3350. DOI: 10.1021/ma00065a017