Polymers 2013, 5(2), 328-343; doi:10.3390/polym5020328
Article

Energetic and Entropic Contributions to the Landau–de Gennes Potential for Gay–Berne Models of Liquid Crystals

Received: 15 February 2013; in revised form: 15 March 2013 / Accepted: 19 March 2013 / Published: 27 March 2013
(This article belongs to the Special Issue Multiscale Simulations in Soft Matter)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: The Landau–de Gennes theory provides a successful macroscopic description of nematics. Cornerstone of this theory is a phenomenological expression for the effective free energy as a function of the orientational order parameter. Here, we show how such a macroscopic Landau–de Gennes free energy can systematically be constructed for a microscopic model of liquid crystals formed by interacting mesogens. For the specific example of the Gay–Berne model, we obtain an enhanced free energy that reduces to the familiar Landau–de Gennes expression in the limit of weak ordering. By carefully separating energetic and entropic contributions to the free energy, our approach reconciles the two traditional views on the isotropic–nematic transition of Maier–Saupe and Onsager, attributing the driving mechanism to attractive interactions and entropic effects, respectively.
Keywords: liquid crystals; Landau–de Gennes potential; coarse graining
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MDPI and ACS Style

Gupta, B.; Ilg, P. Energetic and Entropic Contributions to the Landau–de Gennes Potential for Gay–Berne Models of Liquid Crystals. Polymers 2013, 5, 328-343.

AMA Style

Gupta B, Ilg P. Energetic and Entropic Contributions to the Landau–de Gennes Potential for Gay–Berne Models of Liquid Crystals. Polymers. 2013; 5(2):328-343.

Chicago/Turabian Style

Gupta, Bhaskar; Ilg, Patrick. 2013. "Energetic and Entropic Contributions to the Landau–de Gennes Potential for Gay–Berne Models of Liquid Crystals." Polymers 5, no. 2: 328-343.

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