Twist grain boundaries in cubic surfactant phases

Belushkin, M.; Gompper, G.

doi:10.1063/1.3096987

Journal Article

PreJuSER-4228

Twist grain boundaries in cubic surfactant phases

Belushkin, M.FZJ* ; Gompper, G.FZJ*

2009
American Institute of Physics Melville, NY

The journal of chemical physics 130, 134712 (2009) [10.1063/1.3096987]

This record in other databases:

Please use a persistent id in citations: http://hdl.handle.net/2128/18972 doi:10.1063/1.3096987

Abstract: Twist grain boundaries in bicontinuous cubic surfactant phases are studied by employing a Ginzburg-Landau model of ternary amphiphilic systems. Calculations are performed on a discrete real-space lattice with periodic boundary conditions for the lamellar L(alpha), gyroid G, diamond D, and the Schwarz P phases for various twist angles. An isosurface analysis of the scalar order parameter reveals the structure of the surfactant monolayer at the interfaces between the oil-rich and water-rich regions. The curvature distributions show that the grain boundaries are minimal surfaces. The interfacial free energy per unit area is determined as a function of the twist angle for the G, D, P, and lamellar phases using two complementary approaches: the Ginzburg-Landau free-energy functional and a geometrical approach based on the curvature energy of a monolayer. For the L(alpha), G, and D phases the interfacial free energy per unit area is very small, has the same order of magnitude, and exhibits a nonmonotonic dependence on the twist angle. The P phase is found to be unstable with respect to the nucleation of grain boundaries.

Keyword(s): J ; diamond (auto) ; free energy (auto) ; Ginzburg-Landau theory (auto) ; liquid crystals (auto) ; monolayers (auto) ; surface energy (auto) ; surfactants (auto) ; twist boundaries (auto)