Supramolecular fibers draw widespread attention due to their role in biological systems and ability to form complex materials exhibiting rich and dynamic behavior. Although the information about the supramolecular structure is encoded in their molecular blocks, a complete understanding of how this information translates into the final structure requires detailed insights into the energy landscape of the process and the possible routes across this landscape. Here, we study the formation of 1,3,5-cyclohexanetricarboxamide fibers by a Markov state model of molecular dynamics simulations with the polarizable CHARMM Drude force-field. We provide insights into all stages of supramolecular fiber formation up to microsecond timescales, starting from primary nucleation, through fiber elongation and secondary nucleation, and finally, the assembly of single fibers into bundles. Our results show that nucleation involves a rapid collapse of dissolved monomers into disordered assemblies, which gradually transform into nuclei and then grow into elongated fibers. Moreover, elongation and secondary nucleation appeared to be competing processes, depending on the density of the monomers adsorbed at the fiber-liquid interface. Finally, bundling involves the initial association of fibers by interactions between surface-exposed groups, followed by stabilization of the bundle by surface reorganization, which allows for favorable interactions between aromatic groups.

This study investigates the stabilization of oil/water emulsions as a function of addition of a biopolymer (scleroglucan) which acts as an emulsion stabilizer. Rheological characterization in the form of controlled stress creep measurements has been carried out and it reveals the colloidal gel exhibiting a delayed yielding in a certain applied stress window. The delay time and stresses that an emulsion can withstand depend strongly on the concentration of added scleroglucan. Increasing polymer concentration, however, is limited to a maximum value, above which a limited effect on the delay time is observed. Investigating of the emulsion under study was visualized by means of cryo transmission electron microscopy which shows adsorption of scleroglucan onto the surface of the oil particles and a gel-like structure that connects the oil phases. The results mentioned in this study support that scleroglucan-surfactant interactions play a key role in the stabilization of the oil/water emulsion.

The work presented here shows that the growth of supramolecular hydrogel fibers can be spatially directed at the nanoscale by catalytic negatively charged nanoparticles (NCNPs). The NCNPs with surfaces grafted with negatively charged polymer chains create a local proton gradient that facilitates an acid-catalyzed formation of hydrogelators in the vicinity of NCNPs, ultimately leading to the selective formation of gel fibers around NCNPs. The presence of NCNPs has a dominant effect on the properties of the resulting gels, including gelation time, mechanical properties, and network morphology. Interestingly, local fiber formation can selectively entrap and precipitate out NCNPs from a mixture of different nanoparticles. These findings show a new possibility to use directed molecular self-assembly to selectively trap target nano-objects, which may find applications in therapy, such as virus infection prevention, or engineering applications, like water treatment and nanoparticle separation.