Formation and degradation of multicomponent multicore micelles: insights from dissipative particle dynamics simulations.

Dissipative particle dynamics (DPD) simulation is employed to examine (i) the multicomponent multicore micelle (MMM) formation from two kinds of star-shaped copolymers: A2B4B4 and C2B4B4 where A, B, and C are the segments of the copolymers and (ii) the degradation of multicomponent multicore micelles. Regarding the micelle formation, single-core micelles with the core composed of two components (SCII), multicomponent multicore micelles with each core composed of two components (MMII), multicomponent multicore micelles with each of the cores composed of one component (MMI), and multicomponent multicore rod micelles (MMRI) are considered. By changing the ratio between the number of segments of one of the polymers and the total number of segments of the two copolymers, the number of cores generated and their composition can be controlled. Considering that only C2B4B4 is degraded to 2C1 + 2B4, it was found that SCII, MMII, and MMI micelles degraded to a single irregular network core, to multicores with cores formed of loose aggregates, and to multicore micelles, respectively. The dynamics of micelle formation has several stages (small aggregates (nuclei) → growth of aggregates → micellization) whereas the dynamics of degradation involves the diffusion of the degraded components inside and outside micelles and the rearrangement of the cores of the micelles into new cores.