Embedding DNA in surfactant mesophases: The phase diagram of the ternary system dodecyltrimethylammonium-DNA/monoolein/water in comparison to the DNA-free analogue.

Research output: Contribution to journalArticle

Abstract

The self-assembly of a true ternary mixture comprising an electroneutral complex of DNA anions and surfactant cations (dodecyltrimethylammonium cations, DTA), water, and nonionic surfactant (monoolein, MO) has been studied. The phase diagrams of two systems, DTA-DNA/MO/water and, for comparison, dodecyltrimethylammonium bromide (DTAB)/MO/water, were obtained by visual inspection, microscopic examination under polarized light, small-angle X-ray scattering (SAXS) and deuterium NMR ((2)H NMR) at 298K and normal pressure. The isothermal phase diagram of the DTA-DNA/MO/water system contains four liquid crystalline (LC) phase regions (reversed hexagonal, Pn3m, Ia3d, lamellar). The supramolecular assemblies evolve from a bicontinuous cubic structure of the reversed type to the two-dimensional hexagonal phase as the content of DTA-DNA is increased. While DTA-DNA tends to form a reversed hexagonal phase, DTAB is incorporated into the existing lamellar phase formed by MO and water giving rise to swelling and to significant extension of the lamellar phase region. There is only a small tendency of the cubic phases existing in the binary system MO/water to accommodate DTAB or DTA-DNA.

Details

Authors
  • Azat Bilalov
  • Jonas Elsing
  • Eva Haas
  • Claudia Schmidt
  • Ulf Olsson
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Chemistry
Original languageEnglish
Pages (from-to)360-367
JournalJournal of Colloid and Interface Science
Volume394
Issue numberOnline 28 December 2012
Publication statusPublished - 2013
Publication categoryResearch
Peer-reviewedYes