Unimolecular Janus Micelles by Microenvironment-Induced, Internal Complexation.

A noncentrosymmetric, star-shaped polymeric system is presented, which forms unimolecular micelles upon complexation of poly(propylene oxide) (PPO) with poly(dimethylaminoethyl methacrylate) (PDMAEMA). The influence of macromolecular architecture on the hydrophobicity of PPO and its interaction with PDMAEMA is investigated. Within stars, a complex between PPO and PDMAEMA is formed, lowering the interfacial tension of the hydrophobic domain (PDMAEMA acts as a "microsurfactant" for PPO).

Poly(ether-ester) conjugates with enhanced degradation.

When a linear or a four arm star-shaped polyglycidol is used as macroinitiator, densely grafted poly(glycidol-graft-epsilon-caprolactone) and poly(glycidol-graft-L-lactide) and loosely grafted poly[(glycidol-graft-epsilon-caprolactone)-co-glycidol] copolymers have been synthesized by chemical or, in the latter case, by enzymatic catalyzed ring-opening polymerization of epsilon-caprolactone and L-lactide. The well-defined copolymers possess similar molecular weights, but differ in their architecture, microstructure and chemical composition. The hydrolytic degradation behavior was studied in a phosphate buffer solution at pH 7.

From multifunctionalized poly(ethylene imine)s toward antimicrobial coatings.

Primary amine groups of branched poly(ethylene imine) (PEI) were functionalized with quaternary ammonium groups, alkyl chains of different length, allylic and benzylic groups in a one-step reaction, using a carbonate coupler. The structure of the obtained amphiphilic polymers was determined by means of 1H and 13C NMR spectroscopy. Depending on their hydrophilic/hydrophobic balance, the obtained polymers can be used as water-soluble disinfectants and for antimicrobial coating materials.

Self-organization of polybases neutralized with mesogenic wedge-shaped sulfonic acid molecules: an approach toward supramolecular cylinders.

Complexes consisting of poly(4-vinylpyridine) and mesogenic wedge-shaped ligands 4'-[3",4",5"-tris(dodecyloxy)benzoyloxy]azobenzene-4-sulfonic acid and 4'-[3",4",5"-tris(octyloxy)benzoyloxy]azobenzene-4-sulfonic acid have been prepared with different monomer/ligand ratios. Upon protonation of the poly(4-vinylpyridine) chains by the wedge-shaped sulfonic acid molecules a hypsochromic and hyperchromic effect was observed with the pi-pi* transition of the azo-chromophor, allowing us to monitor the neutralization process by means of UV-vis spectroscopy in solution. The changes of the absorption characteristics implied a conformational change of the polymer backbone.