From fundamental design to applications of supramolecular polymer bottlebrushes

By employing supramolecular chemistry, dynamic materials of different size and shape, however mostly lacking the complexity found in nature, are accessible. Nature's ability to organize macromolecular building blocks into hierarchical 1D structures inspired chemists to employ an interplay between polymer science and non-covalent synthesis to generate various anisotropic supramolecular polymeric systems with interesting properties, such as stimuli-responsiveness and a dynamic character. One way to form 1 dimensional, supramolecular polymer structures, is to employ weak directed interactions such as hydrogen bonds. This thesis aimed to evaluate the prerequisites for the formation of supramolecular polymer bottlebrushes via the self-assembly of 1,3,5-benzene trisamides equipped with polymer chains in water. To do so, the influence of interaction strength between the self-assembly units, the hydrophobic shielding, and the hydrophilicity of the polymer exterior was evaluated. Here, the strong effect of the packing parameter could be observed, besides the need for strong directional forces as exhibited by hydrogen bonds between urea groups. Furthermore, the assembly mechanism of the resulting supramolecular polymer bottlebrushes and the possibility of employing kinetic control over the system to tune the resulting sizes were examined. Further research has been conducted on the interaction between fibers from benzene trisurea building blocks obtained by pathway-dependent self-assembly at higher concentrations. At high concentrations the systems gel due to the entanglement of the nanofibers. Since these gels are of supramolecular nature, the aggregates can be reversibly broken and thus these gels feature stress-responsiveness and self-healing abilities. By utilizing different amounts of crosslinker and varying overall concentration, biocompatible hydrogels could be synthesized which can be processed by 3D printing methods.