Self-Assembly and Dynamics Driven by Oligocarbonate-Fluorene End-Functionalized Poly(ethylene glycol) ABA Triblock Copolymers

Abstract

The closed assembly transition from polymers to micelles and open assembly to clusters are induced by supramolecular π-π stacking in model oligocarbonate-fluorene (F-TMC) end-group telechelic polymers. The critical micelle concentration (CMC) depends on the F-TMC degree of polymerization that further controls the weak micelle association and strong clustering of micelles regimes. Clustering follows a multistep equilibria model with average size scaling with concentration reduced by the CMC as R ∼ (c/CMC)1/4. The F-TMC packing that drives the supramolecular self-assembly from polymers to micelles stabilizes these larger clusters. The clusters are characterized by internal relaxations by dynamic light scattering. This signifies that while F-TMC groups drive the clustering, the micelles interconnected via F-TMC bridging interactions remain coupled to the extent that the clusters relax via Rouse-Zimm dynamics, reminiscent of microgels.