Impact of subtle change in branched amino acid on the assembly and properties of perylene bisimides hydrogels

We investigate how apparent slight changes to the chemical structure of amino acid-functionalised perylene bisimides (PBIs) affect the self-assembled aggregates formed and their resulting physical and optical properties. PBIs functionalised with L-valine (PBI-V), L-leucine (PBI-L) and L-isoleucine (PBI-I) are investigated due to their similarly branched structure and their assemblies in water were studied using UV-vis absorption spectroscopy, cyclic voltammetry (CV), small angle X-ray scattering (SAXS) and viscosity at different pHs. It was seen that each PBI behaved differently. Each of the PBIs were then used to prepare hydrogels, and their properties again assessed, with PBI-I forming different hydrogels than the other PBIs. By understanding how slight changes in chemical structure can affect bulk properties we become a step closer to designing gels with specific physical and electrical properties.