Rheological characterisation of bis-urea based viscoelastic solutions in an apolar solvent

The rheological properties of hydrogen bonded reversible aggregates in apolar solvent have been investigated. The zero shear viscosity, the plateau modulus and the terminal viscoelastic relaxation time exhibit power laws dependencies with the concentration that have been compared with the behaviours expected for reversible polymers. It appears that the dynamics originate from scission/recombination mechanisms. Moreover, the growth of the aggregates with concentration follows the laws observed and predicted for worm-like micelles at low concentrations allowing the length of the aggregates to be estimated 500 nm at 3 g L−1. However, at the highest concentrations investigated, deviations from the power laws suggest the presence of some intrinsic chain stopper poisons in the solutions.

When dissolved in apolar solvents, bis-urea self assemble into flexible filaments leading to viscoelastic solutions. Their dynamics originate from scission/recombination mechanisms like for surfactant-based worm-like micelles.Figure optionsDownload as PowerPoint slide