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

Linear rheology of bis-urea functionalized supramolecular poly(butylacrylate)s: Part I – weak stickers

“…In earlier investigations of our group, the self-assembly and rheology of Ethyl Hexyl bis-Urea Toluene (EHUT), a strongly interacting polar molecule, in a non-polar solvent was extensively studied 33,34 . This small molecule (M n ~ 400 g/mol), chemically close to our bis-urea sticker, self-assembles into long rods in non polar solvents and the viscoelastic behavior of such solutions was well described by the theory of living polymers 17 proposed by Cates in the fast scission regime.…”

“…Figure 10: Cole-cole plot for PnBAX5 (A) and solutions of EHUT (B) in dodecane (reprinted from reference 34 ). The experimental data for PnBAX5 were measured at different temperatures while the experimental measures for EHUT solutions were obtained at different concentrations from c=2.9 to c=10g/L in dodecane, increasing in the direction of the arrow.…”

Large amplitude oscillatory shear of supramolecular materials

“…The hydrogen bonding between the amide groups and oxygen, represented by the dotted lines, is responsible for the aggregation. The tubular structures shown in the figure form entanglements/meshes which entrap the dodecane solvent [6,8]. It is also known that EHUT does not form these tubular structures in bulky solvents [9].…”

“…2,4 bis(2-ethyl hexyl ureido)toluene [EHUT], an organic gelator, has been shown to form tubular equilibrium aggregates in solvents such as dodecane [6]. The molecular structure of the EHUT monomer and the tubular aggregate are shown in Fig.…”

“…EHUT has been investigated for applications such as drag reducing agent and hardener for asphalt [10][11][12]. Supramolecular polymers, such as EHUT gels, have been characterized using rheological techniques like steady shear and dynamic oscillatory shear tests [6,[13][14][15]. The linear viscoelastic response of the gels was shown to be similar to the Maxwell model.…”