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A novel supramolecular miktoarm star polymer was successfully constructed in water from a pyridine end-decorated polymer (Py-PmDEGA) and a metalloporphyrin based star polymer (ZnTPP-(PEG) 4 ) via metal-ligand coordination. The Py-PmDEGA moiety was prepared via a combination of reversible addition-fragmentation chain transfer polymerization (RAFT) and subsequent aminolysis and Michael addition reactions to introduce the pyridine end-group. The ZnTPP(PEG) 4 star-polymer was synthesized by the reaction between tetrakis(p-hydroxyphenyl)porphyrin and toluenesulfonyl-PEG, followed by insertion of a zinc ion into the porphyrin core. The formation of a well-defined supramolecular AB 4 -type miktoarm star polymer was unambiguously demonstrated via UV-Vis spectroscopic titration, isothermal titration calorimetry (ITC) and diffusion ordered NMR spectroscopy (DOSY).

We report on a straightforward strategy to fabricate bioactive glycosylated gold nanoparticles via a combination of RAFT polymerization, carbohydrate ligation through reductive amination and thiol-gold self-assembly. This approach is used for the design of gold nanoparticles decorated with the complex sialylated glycan Neu5Ac-α-2-6-Gal, and we demonstrate multivalent and specific recognition between the nanoparticles, lectins and hemagglutinin on the surface of the influenza virus.

We report on transiently responsive protein-polymer conjugates that temporarily change their protein conformation from the soluble to the particle-like state. 'Grafting-from' RAFT polymerization of a dioxolane-containing acrylamide with a protein macroCTA is used to design polymer-protein conjugates that self-assemble into nanoparticles at physiological temperature and pH. Acid triggered hydrolysis of the dioxolane units into diol moeities rendered the conjugates fully water soluble irrespective of temperature.

Cationic ring-opening polymerizations of 2-oxazolines were investigated in continuous microflow reactors. Fast homopolymerizations of 2-ethyl-2-oxazoline (EtOx) and 2-n-propyl-2-oxazoline (nPropOx) were carried out up to 180 °C, yielding well-controlled polymers. Also well-defined diblock and triblock copolymers were produced in a microfluidic reactor cascade, demonstrating the high value of microflow synthesis for the built-up of advanced poly(2-oxazoline)-based polymers.

Polyampholytes with controlled equimolar ratio of charges were synthesized by reversible addition-fragmentation chain transfer (RAFT) copolymerization of cationic and anionic monomers. The resulting charge-neutral polyampholytes exhibit upper critical solution temperature (UCST) thermoresponsive behavior in ethanol-water and methanol-water solvent mixtures based on electrostatic attraction. Finally, the temperature induced self-assembly of a polyampholyte with oligo(ethylene glycol) side chains into defined nanoparticles below the UCST transition is demonstrated.

Polymeric multilayer films assembled via hydrogen-bonding are witnessing increased interest from the scientific community. Here we report on hydrogen bonded multilayers of tannic acid and neutral poly(2-oxazoline)s. Importantly we demonstrate, to the best of our knowledge, for the first time that a temperature responsive polymer, in this case poly(2-(n-propyl)-2-oxazline), can be assembled below and above its TCP with distinctly different growth mechanisms.

We describe the synthesis of self-assembling cyclic octapeptides of alternating D- and L-chirality conjugated to two poly(2-ethyl-2-oxazoline) chains. The resulting conjugates form nanotubes in water, which are reversibly transformed into microparticles as the temperature reaches the cloud point temperature of the conjugate.

An efficient method for the preparation of cyclopentadienyl endcapped poly(2-ethyl-2-oxazoline) (PEtOx-Cp) via cationic ring-opening polymerization utilizing sodium cyclopentadienide as a termination agent is presented. Subsequent Diels-Alder reactions with N-substituted maleimides proceed quantitatively at ambient temperature. A block copolymer (PEtOx-b-PEG) is prepared employing maleimide terminated poly(ethylene glycol)., (This journal is © The Royal Society of Chemistry 2011)

This feature article provides, for the first time, an overview of the research that guided the way from fundamental studies of the thermo-responsive phase separation of aqueous polymer solutions to polymeric sensor systems. The incorporation of solvatochromic dyes into thermoresponsive polymers as well as the concepts of polymeric sensors are presented and discussed in detail., (This journal is © The Royal Society of Chemistry 2011)

The aqueous gelation of a quaternary ammonium oligo(propylene oxide)-based ionic liquid yields ion gels with a reverse thermoresponsive behavior (i.e., mechanical moduli and viscosity increase with temperature) and enhanced ionic conductivities.

The self-assembly of a new type of triblock terpoly(2-oxazoline) was investigated in water revealing vesicular and aggregated cylindrical micellar structures.

Micellization and micellar gel formation of poly(styrene)-block-poly(methyl methacrylate) [PS-b-PMMA] are demonstrated in a water-ethanol solvent mixture; full hydration of the PMMA causes a large radius of gyration resulting in micellar gel formation at only 1 wt% polymer concentration.

The synthesis of a new difunctional nitroxide initiator combining two orthogonal supramolecular entities is reported; controlled radical polymerization of styrene using this initiator is demonstrated to generate well-defined heterotelechelic polymers in a one-step procedure.

The cloud point of copolymers of 2-ethyl-2-oxazoline and 2-n-propyl-2-oxazoline could be tuned from 25 degrees C to 100 degrees C by varying molecular weight and composition; the reversibility and concentration dependence of the cloud points were evaluated to assess the potential of these copoly(2-oxazoline)s as alternatives to poly(N-isopropylacrylamide).

This communication reports a versatile post-modification reaction of poly(pentafluorostyrene) building blocks in order to design multifunctional graft copolymers by taking advantage of the selective replacement of the para-fluorine groups.

Poly(2-nonyl-2-oxazoline-block-2-ethyl-2-oxazoline) block copolymer micelles were investigated as an alternative system to the approach proposed by He and Lodge (Y. He and T. P. Lodge, J. Am. Chem. Soc., 2006, 128, 12666) for the thermoreversible transfer of micelles between a hydrophobic ionic liquid phase and an aqueous phase; this work describes the possibility of thermally triggering and controlling this process.

The living cationic ring-opening polymerization of 2-oxazolines with fluorinated aromatic substituents was found to be strongly accelerated by o-fluoro substituents.

Intrigued by natural responsive systems based on a combination of macromolecules and non-covalent interactions, polymer scientists have mimicked such systems by the formation of supramolecular polymers based on ionic interaction, hydrogen bonding and metal coordination. In recent years, the focus has shifted from rather simple non-directional and self-complementary interactions to the use of asymmetrical directional supramolecular interactions that allow the formation of complex responsive macromolecular architectures such as block copolymers, star-shaped polymers and graft copolymers. This feature article covers these recent developments on the use of asymmetrical supramolecular interactions in polymer science. Special attention is given to the formation of complex macromolecular architectures using directional supramolecular interactions. In addition, the responsiveness of the resulting macromolecular systems is discussed based on the assembly and/or disassembly that can be triggered by changes in external conditions.

The synthesis of star-shaped poly(epsilon-caprolactone) is described via azide-alkyne cycloaddition ('click' chemistry) and via self-assembly of polymeric ligands into [2 x 2] grid-like metal complexes ('supramolecular click' chemistry).

The living cationic ring opening polymerization of 2-ethyl-2-oxazoline performed in an ionic liquid under microwave irradiation showed an enhanced polymerization rate in comparison to the reaction in common organic solvents; the ionic liquid was efficiently recovered and reused in new reaction cycles, completely avoiding the use of organic volatile compounds.