Packing entropy in micelle self-assembly

Results are presented from simulations of a lattice model which exhibits th e self-assembly of micelles and a well-defined critical micelle concentrati on. It is possible, unambiguously, to extract the entropy associated with p acking the chains into a micelle and to demonstrate that micellisation aris es From a competition between the enthalpy and the packing entropy of the c luster. The effect; of changing the length of the amphiphile head is report ed and it is found that the loss of entropic freedom of the headgraups cont rols the position of the cmc.