Despite interest from both industry and academia, simulating mixed surfactant micelles remains a challenge for modern computational chemistry.  The problem for molecular dynamics (MD) simulations is two-fold: i) The concentration of surfactants is low, millimolar or less, which requires a large number of waters per surfactant, and ii) micellization timescales are on the order of microseconds, far longer than a typical MD simulation.  Presented in this work is a method to overcome these constraints, which combines a coarse-grained model of aqueous surfactants with graphics processing unit accelerated MD software.  Using this method, we have investigated micellization of mixtures of both non-ionic (polyethylene glycol) and ionic (sodium alkyl sulfate) surfactants as a function of hydrocarbon chain length and relative surfactant concentration.  A number of thermodynamic, morphological, and dynamic properties are predicted from the simulation data, including aggregation number, polydispersity, critical micelle concentration, radius of gyration, molecular eccentricity, and monomer exchange lifetimes.

Simulating the self-assembly of mixed surfactant micelles with graphics processing unit accelerated coarse-grained molecular dynamics

243rd National Meeting (2012)

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