Micellization Dynamics and Impurity Solubilization of the Block-Copolymer L64 in an Aqueous Solution

The dynamics of the micellization of Pluronic® L64 (EO₁₃PO₃₀EO₁₃, PEO/PPO = 2/3) was studied by employing the iodine laser temperature-jump technique. These studies show a more complex behavior than previously described. Three relaxation processes were observed, depending on the temperature at which experiments were performed. The first two of these relaxation processes are related to the unimer incorporation into micelles and the redistribution of micelles after incorporation of the unimers. The third relaxation process, which had not been previously observed, occurs at high temperatures and is related to the clustering of micelles into larger aggregates. In addition, the presence of impurities and hydrophobic components was shown for the first time to significantly affect the dynamics of L64 micellization.