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.

Flower-like Micelles of Polyethylene Oxide End-Capped with Cholesterol

“…Figure shows the distribution functions of hydrodynamic radii R h s of the P1, P2, and P3 solutions (with the same polymer concentration of 2.5 mg/mL), analyzed from their field correlation functions (Figure S6), yielding (103 ± 2), (140 ± 3), and (192 ± 3) Å, respectively, as the average of five measurements (Table ). No large clusters (i.e., >500 Å) originating from the bridging micelles are found, as previously reported from other ABA triblock copolymers . The average scattering intensity of P1 is always higher than the other two with all at the same concentration.…”

“…No large clusters (i.e., >500 Å) originating from the bridging micelles are found, as previously reported from other ABA triblock copolymers. 16 The average scattering intensity of P1 is always higher than the other two with all at the same concentration. Note that all the scattering species (even for the largest one) are in the Guinier regime, where qR is less than 1 (in fact <0.3); therefore, it is expected that the intensity of the smaller objects at the same concentration would result in a lower intensity.…”

“…Flower-like micelles, − larger micellar bridging clusters, − and unimers − can be formed in certain triblock copolymers with the middle block and two end blocks being solvophilic and solvophobic, respectively. It has been proposed that as a result of solvophobic interactions, the end blocks could form the core of the micelles with the middle block adopting a hairpin configuration to form the corona of the micelles.…”

Fast-Bactericidal Effect of Polyion Complex Nanoparticles on Gram-Negative Bacteria

“…Such high Rg/Rh value indicates that PIC nanoparticles could possess an anisotropic shape. 32 It appears that zeta-potential of homopolymers PAMPTMA trend more positive with increasing chain length, while block copolymers PAMPTMA-b-PBuMAc present even higher zetapotential than homopolymers. It is known that zeta-potential significantly depends on particle property and solution conditions.…”

“…For all PIC nanoparticles, independent of the molecular weight, the value of R g / R h is about 1.7. Such a high R g / R h value indicates that PIC nanoparticles could possess an anisotropic shape …”