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arXiv · 1010.1421

Simulations of a lattice model of two-headed linear amphiphiles: influence of amphiphile asymmetry

Douglas R. Jackson·Amir Mohareb·Jennifer MacNeil·M. Shajahan G. Razul·D. Gerrard Marangoni·Peter H. Poole
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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.

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Douglas R. Jackson, Amir Mohareb, Jennifer MacNeil, M. Shajahan G. Razul, D. Gerrard Marangoni, Peter H. Poole. 2010-10-07. Simulations of a lattice model of two-headed linear amphiphiles: influence of amphiphile asymmetry. https://doi.org/10.1063/1.3593404

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