A fundamental understanding of the thermodynamic aspects of self-assembly is quintessential to develop supramolecular polymers with desired properties. This task is especially challenging in aqueous systems where supramolecular polymerization is principally determined by the intricate interplay between entropic contribution from solvation/dissolution of monomeric units and enthalpic contributions arising from the solvation of extended aggregates. We recently reported on the self-assembly behavior of bolaamphiphilic perylene bisimide dyes appended with oligoethylene glycol (OEG), which show an entropically driven aggregation process in water, while the process is enthalpically driven in the presence of THF as a co-solvent (Figure 1a).In the present study, a detailed thermodynamic profile of the self-assembly of various OEG based bolaamphiphilic rylene dyes is carried out in water at different temperatures, using isothermal titration calorimetry and UV/ Vis studies (Figure 1b). Remarkably, we found that the entropic release of water from the OEG chains overcomes the enthalpic contribution from π- π stacking interactions (Figure 1c), which has a determining influence on the thermodynamics of the aggregation process. This fundamental study sheds light on thermodynamics aspects of self-assembly in water, providing new elements to control the aggregation processes.

Thermodynamic insights into the entropically driven self-assembly of rylene bisimide dyes in water

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.