title: Simulations of a lattice model of two-headed linear amphiphiles: influence of amphiphile asymmetry.
abstract: Using a 2D lattice model, we conduct Monte Carlo simulations of micellar aggregation of linear-chain amphiphiles having two solvophilic head groups. In the context of this simple model, we quantify how the amphiphile architecture influences the critical micelle concentration (CMC), with a particular focus on the role of the asymmetry of the amphiphile structure. Accordingly, we study all possible arrangements of the head groups along amphiphile chains of fixed length N = 12 and 16 molecular units. This set of idealized amphiphile architectures approximates many cases of symmetric and asymmetric gemini surfactants, double-headed surfactants, and boloform surfactants. Consistent with earlier results, we find that the number of spacer units s separating the heads has a significant influence on the CMC, with the CMC increasing with s for s < N/2. In comparison, the influence of the asymmetry of the chain architecture on the CMC is much weaker, as is also found experimentally.
authors.affiliation: Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4J3, Canada.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Jackson
authors.forename: Amir
authors.initials: A
authors.lastname: Mohareb
authors.forename: Jennifer
authors.initials: J
authors.lastname: MacNeil
authors.forename: M Shajahan G
authors.initials: MS
authors.lastname: Razul
authors.forename: D Gerrard
authors.initials: DG
authors.lastname: Marangoni
authors.forename: Peter H
authors.initials: PH
authors.lastname: Poole