Biomedical subjects
Publications and source records attributed to René Pool.
We report molecular simulations suggesting that the kinetics of surfactant micelle formation can be sped up significantly by a replication mechanism, in which growing micelles become unstable and split into two similar sized micelles. We argue that for certain surfactants types around the critical micelle concentration, such a mechanism becomes more dominant than the commonly accepted nucleation pathway.
We determine the free energy of micelle formation for surfactants in a solvent by employing a hybrid semi-grand Monte Carlo simulation scheme in combination with umbrella sampling and configurational bias techniques. We compare results of two surfactant models: one based on Lennard-Jones interactions and one based on the soft repulsive potential that is often used in dissipative particle dynamics (DPD). The free energies of micellization in both models show similar behavior. However, although the critical micelle concentration for the Lennard-Jones systems lies within the experimental range, it is 13 orders of magnitude lower for the soft repulsive model. We discuss the implication for the applicability of soft repulsive potentials for the study of micelle formation.
We determine the free energy of micelle formation for model surfactants in a Lennard-Jones solvent by employing a hybrid semi-grand Monte Carlo simulation scheme in combination with umbrella sampling and configurational bias techniques. Comparing the results to theoretical prediction, we obtain good agreement for large micellar sizes. We also study the effect of changing the surfactant headgroup size and tail length on the critical micelle concentration. The values of and the trends in the calculated critical micelle concentrations do agree with experimental observation for nonionic surfactants. The results open up the way for the calculation of critical micelle concentrations using realistic atomic force fields.