초록 |
We will present novel block copolymers with long fluoroalkyl pendent chain, which show bottlebrush-polymer-like behavior (e.g., negligible entanglement and relatively large free volume), and the impact of such behavior on the dynamics of self-assembly. In a selective solvent, the copolymers readily self-assembled to micelles having super-stretched core, due to the strong incompatibility of the fluoroalkyl core block with the solvent. However, the exchange of single polymer chain between micelles was found to be exceptionally fast at near-ambient temperature, despite of high energy penalty for the chain pull-out. Kinetic study of the chain exchange was performed using time-resolved small-angle neutron scattering (TR-SANS), and an existing model for micelle dynamics was found to nicely describe the results quantitatively. We attribute this fast exchange to significantly low friction of the fluoroalkyl block, which may be originated from its bottlebrush-type molecular characteristics. |