Surface patterns, formed by the coassembly of cationic-anionic amphiphiles into cylindrical micelles, were analyzed. The competition between electrostatic forces and the net incompatibility χ arising from the different chemical natures of those oppositely charged amphiphiles resulted in the formation of segregated domains. These surface domains are not macroscopically segregated due to the electrostatics penalty associated with their growth. In charged stoichiometric coassemblies into cylinders, a lamellar-charged surface pattern is predicted analytically and observed by Monte Carlo simulations. The symmetry of the lamellar pattern is either ring (perpendicular to the long cylinder axis) or helical. Previous work was extended by incorporating variance of the dielectric constant of the medium εo to different values of the cylinder’s radius Rc and χ and studying how the transition between these two symmetries is affected. The critical surface in the space {Rc, εo, χ} separating the helical and ring symmetries is presented and its dependence on εo computed. It was found that εo is a significant parameter in the control of the helical-ring transition; the ring pattern is strongly associated with the prevalence of short-range nonelectrostatic forces, while the helical pattern develops in response to a greater predominance of long-range electrostatic strain.

Last modified

• 07/18/2018

Creator

• Marc Michael D. Lim
• Yury S. Velichko
• Graziano Vernizzi
• Monica Olvera de la Cruz

DOI

• https://doi.org/10.21985/N2142Z

Keyword

• Volume 4

Date created

• 2007

Resource type

• Article

Rights statement

• In Copyright