Free energy of semiflexible polymers and structure of interfaces

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

The free energy of semiflexible polymers is calculated as a functional of the compositional scalar order parameter φ and the orientational order parameter of second-rank tensor Sij on the basis of a microscopic model of wormlike chains with variable segment lengths. We use a density functional theory and a gradient expansion to evaluate the entropie part of the free energy, which is given in a power series of Qij = Sij/φ. The interaction term of the free energy is derived with a random phase approximation. For the rigid rod limit, the nematic-isotropic transition point is given by Nwφ = 4.05141, N and w being the degree of polymerization and the anisotropic interaction parameter, respectively, and the degree of ordering at the transition point is 0.33448. We also find that the contour length of polymer chains becomes larger in a nematic phase than in an isotropic phase. Interface profiles are obtained numerically for some typical cases. In the neighborhood of isotropic-isotropic interfaces, polymer chains tend to align parallel to the interface on the polymer-rich side and perpendicular on the poor side. When an isotropic region and a nematic region coexist, orientational order parallel to the interface is preferred in the nematic region.

Original languageEnglish
Pages (from-to)573-583
Number of pages11
JournalEuropean Physical Journal B
Volume7
Issue number4
DOIs
Publication statusPublished - Feb 2 1999
Externally publishedYes

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this