The role of geometric constraints in amphiphilic self-assembly: A Brownian dynamics study

We use a stochastic molecular dynamics simulation method to investigate the effect of optimal head group area in amphiphilic self-assembly. For a fixed tail geometry, we choose several sizes of the effective head group area and carry out a detailed study of how this affects the critical micelle concentration ~CMC!, the cluster distribution, and the shape of micelles for different concentrations and temperature. We find that with an increase of the effective head group area, the CMC is attained at a larger concentration of the free chains at all temperatures. Likewise, for a given concentration, amphiphiles with the larger effective head group exhibit a sharper cluster distribution with a tendency to form more spherical micelles. Our study shows a way to control the size and shape of the micelles and can have potential impact on the synthesis of nano-structures through surfactant mediated templating methods. © 2003 American Institute of Physics. @DOI: 10.1063/1.1614210#