En route to intelligent hydrogels: Copolymers of N‐isopropylacrylamide containing adamantyl groups can be cross‐linked noncovalently with cyclodextrin dimers. This results in thermosensitive hydrogels with cloud points that are lower than those of the pure copolymers. Addition of monomeric methylated cyclodextrin results in an increase in the cloud points but has no significant influence on the viscosity of the copolymer solution.

In this paper, we would like to present a novel system of host-guest hydrogels. By polymerizing adamantyl containing acrylamide monomers (12-15) with water soluble comonomers, we synthesized various copolymers bearing guest components. As host system we applied easily accessible β-cyclodextrin polymers with M n values of about 30K-100K g mol -1 . The viscosity of the resulting hydrogel could be influenced by the concentration of both substances, by the length of the carbon spacer chain of the guest monomer, by the pH value or by the conformation of the β-cyclodextrin polymers. Moreover, the hydrogels stayed stable in solutions of starch hydrolyzing enzyme taka-diastase from Aspergillus oryzae.

In this study, the association ("electrostatic self-assembly") of cationic generation 4 poly(amidoamine) dendrimer with a set of oppositely charged aromatic and aliphatic organic sulfonate counterions was investigated. Aggregate size and shape depend on the counterion structure. Formation of defined assemblies was possible with stiff, mutually interacting aromatic azo-dye counterions (acid red dyes Ar26, Ar44, Ar27, Ar18) but not with flexible or small aliphatic disulfonates and sulfate. Dynamic light scattering yielded sizes in the order of 100 nm. Particle shapes as investigated by small-angle neutron scattering were spherical, ellipsoidal, cylindrical, or of core-shell type. Results revealed that the molar charge ratio of the components is a crucial factor in the aggregation. UV-vis showed a cooperative binding process and yielded twist angles of dye molecules of 15 degrees to 30 degrees according to exciton theory. Isothermal titration calorimetry on dendrimer-dye assembly formation and comparison systems gave information on thermodynamics and contributing interaction energies. The main enthalpic contribution was provided by the mutual interaction of the dye molecules, while electrostatic interaction contributes a maximum of about 1/3 of the total interaction enthalpy.

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