Eur. Phys. J. E 8, 499-506 (2002)
Incorporating DNA in a lamellar phase: A Flory modelA. Colin and D. Roux
Centre de recherche Paul-Pascal CNRS, Avenue Dr Schweitzer, 33600 Pessac, France email@example.com
(Received 16 December 2001 and Received in final form 27 June 2002 Online publication 8 October 2002)
Following an experimental work demonstrating that DNA pieces can be incorporated in large quantity in a neutral lamellar phase, we propose a theoretical model showing that finite-size rod-like particles can be incorporated in a lyotropic smectic-A phase with an interlamellar spacing smaller than the rod length. This model based on a Flory-type description on a lattice allowed us to calculate a ternary (rods/water/surfactant) phase diagram. We demonstrate that a particle-enriched lamellar phase and a particle-depleted lamellar phase can coexist. In the latter case the rods exhibit a long-range (nematic-like) orientational order. The predictions are in qualitative agreement with the experiments.
61.30.St - Lyotropic phases.
87.68.+z - Biomaterials and biological interfaces.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2002