Micellization behavior of Poly[2,7-(9,9-dihexylfluorene)]-$b$-Poly(2-vinylpyridine) in MeOH/THF Mixed Solvents via a Combination of Coarse-Grained and All-Atom Molecular Dynamics Methods

Coarse-grained (CG) and all-atom (AA) molecular dynamics (MD) methods are proposed to investigate the micellar behavior of a semiconducting conjugated diblock polymer, poly[2,7-(9,9-dihexylfluorene)]-$b$-poly(2-vinylpyridine) (PF-$b$-P2VP) in MeOH/THF. We adopt the iterative Boltzmann inversion method to obtain CG force filed through mapping route with AA MD data. In order to compare experimental result [1], we first choose PF$_{8}$-$b$-P2VP$_{11}$ with $\Phi =$0.1 and varying ratio of MeOH/THF. When MeOH/THF $=$ 0/100, due to the fact the THF is a common solvent. We observe no micellar formation with increasing ratio of P2VP selective solvent in MeOH/THF from 0/100 to 30/70. The PF block tends to aggregate to form micelles, and size of micelle keeps increasing. The spherical micelles transform into the worm-like formation in 90/10. Our simulation results are in agreement with the experimental study, indicating the constructive CGMD parameters are successful to describe the PF-$b$-P2VP in MeOH/THF.\\[4pt] [1] \textit{Macromolecules}, \textbf{41}, 8759-8769 (2008)