Temperature Effect on Supramolecular Hydrogel Gelation Process: A High-Resolution and Fast-Field Cycling NMR Study

Peptide-based supramolecular hydrogels are well known for their biocompatibility and the various range of applications in biotechnologies. The grafting of nucleobases along with the multicomponent approach allows a fine tuning of the hydrogel properties to match new uses. Such adjustments rely on a precise understanding of the material at the atomic level, and nuclear magnetic resonance (NMR) spectroscopy is a tool of choice for soft matter study. High-resolution NMR and fast-field cycling NMR relaxation can be used to investigate the hydrogel gelation process through the study of the gelator signal and the water dynamical behavior along the gelation time. NMR dispersion profiles can also bring insights into the presence of different water pools and their mobility inside the hydrogel matrix by modeling dispersion curves and extracting correlation times. Measurements were performed at two different temperatures, 295 K and 313 K. Examining the effect of temperature provides insight into the mechanism underlying the transition from solution to gel. This approach highlights not only how an increase in temperature influences the gelation process but also how it affects solvent dynamics within the gelator structure.