Self-Assembly Behavior of Bis(terpyridine) and Metallo-bis(terpyridine) Pluronics in Dilute Aqueous Solutions Manuela Chiper, Stephanie Hoeppener, Ulrich S. Schubert, Charles-Andre ´ Fustin,* Jean-Franc ¸ois Gohy* Introduction Water soluble poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) triblock copolymers generally known as PEO x -PPO y -PEO x are commercially branded as Poloxomers (produced by ICI) or Pluronics (produced by BASF). Their numerous applications in various industrial fields (e.g., dispersion stabilization, foaming, emulsification, drug delivery, separation, ink, etc.) prove once more the benefit of the self-assembly process of block copolymers in solution. [1] In comparison to poly(ethylene oxide) (PEO), which is hydrophilic in a large interval of temperature, the interaction of poly(propylene oxide) (PPO) with water is strongly temperature dependent (PPO is hydrophilic at temperatures lower than 4 8C and molecular masses lower than 1 000 g  mol 1 ). Consequently, Pluronics act as amphiphilic systems in which the interaction with water can be manipulated by varying their com- position and the temperature. [2] Indeed, the phase behavior of these non-ionic amphiphilic copolymers is strongly influenced by the composition, molecular mass and concentration of the block copolymer, and more importantly by the temperature and nature of the utilized solvent or mixture of solvents. Thus, various micellar morphologies including spheres and rod-like micelles have been reported for Pluronics in solution (e.g., water, alcohols, etc.). [3,4] Full Paper M. Chiper, C.-A. Fustin, J.-F. Gohy Institute of Condensed Matter and Nanosciences (IMCN), Universite ´ catholique de Louvain (UCL), Place Pasteur 1, 1348 Louvain-la-Neuve, Belgium E-mail: charles-andre.fustin@uclouvain.be, jean-francois.gohy@uclouvain.be S. Hoeppener, U. S. Schubert Laboratory of Organic and Macromolecular Chemistry, Friedrich- Schiller-Universita ¨t Jena, Humboldtstraße 10, 07743 Jena, Germany Bis(terpyridine) and metallo-bis(terpyridine) Pluronics have been synthesized starting from commercially available P105 and P123 hydroxytelechelic Pluronics. The grafting of terpyridine ligands at the extremity of the Pluronic chains results in the further association of the Pluronic micelles in water. Increasing temperature decreases the solubility of the Pluronics, but also increases the solubility of the terpyridine groups. The addition of 0.5 equiv. nickel(II) ions compared to terpyridine groups induces the formation of bis(terpyridine) nickel(II) complexes and disrupts the initial hydrophobic terpyr- idine aggregates. In that case, formation of flower-like micelles in which the coronal chains form loops due to the terpyridine nickel(II) complexes is observed in the dilute regime. Macromol. Chem. Phys. 2010, 211, 2323–2330 ß 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim wileyonlinelibrary.com DOI: 10.1002/macp.201000484 2323