Core-shell-corona micelles by PS-b-P2VP-b-PEO copolymers:: Focus on the water-induced micellization process

It is now well established that amphiphilic PS-b-P2VP-b-PEO linear triblock copolymers can form multilayered assemblies, thus core-shell-corona (CSC) micelles, in water. Micellization is triggered by addition of a small amount of water into a dilute solution of the PS-b-P2VP-b-PEO copolymer in a non-selective organic solvent. However, the phenomena that take place at the very beginning of this process are poorly documented. How these copolymer chains are perturbed by addition of water was investigated in this work by light and neutron scattering techniques and transmission electron microscopy. It was accordingly possible to determine the critical water concentration (CWC), the compactness of the nano-objects in solution, their number of aggregation, and their hydrodynamic diameter at each step of the micellization process.