Example of the evolution of a branched micelle from a supersaturated surfactant solution

1. Collaborative Research: Development of Additive Selection Criteria based on Interface Complexions W. Craig Carter, Massachusetts Institute of Technology, DMR 0906931 Outcome: Researchers at MIT developed a new model which predicts branching morphologies in growth of micelles and their effect on physical properties. Impact: Emulsification polymerization and targeted drug delivery depend on the physical properties of micelle suspensions; the evolution of such suspension has been modeled. Explanation: Micelles precipitate out of solutions that have supersaturated surfactant concentrations. The micelles are composed of hydrophobic/phillic head-tail groups which generally have different sizes. Thus, the micelle tends to have a preferred curvature. Analogous to dendritic growth, a growing micelle’s morphology is a competition between surfactant absorption, reduced surface energy, and local equilibrium curvature. We have established the conditions for growing micelles to form branched structures; the branches cause a discontinuous change in the viscosity of a micelle suspension Example of the evolution of a branched micelle from a supersaturated surfactant solution