Non-Newtonian viscous shear thinning in ionic liquids

Physico-Chemical Properties of Non-Newtonian Shear Thickening Diisopropyl-ethylammonium-Based Protic Ionic Liquids and Their Mixtures with Water and Acetonitrile

“…Non-Newtonian shear thinning behaviors have been then reported for different AILs and recently for PILs. 50 For the PILs studied, we have first observed a nonlinear relationship between the shear stress and the shear rate, which corresponds to a non-Newtonian behavior as reported in Figure 3. Thus, the shear stress increases monotonically with the shear rate until a shear rate close to (5000 and 4000) s The zero-shear viscosity (denoted η 0 ) and the viscosity (η) are reported in Table 6 for all the pure compounds studied.…”

“…Nevertheless, by increasing the added water in a PIL, presenting originally a non-Newtonian shear thinning behavior, Burrell et al showed that the flow behavior of the mixture changes from nonNewtonian shear thinning to Newtonian and then from Newtonian to non-Newtonian shear thickening. 49,50 Altin et al 56 have reported, in the case of the Newtonian IL 1-ethyl-3-methyl ethylsulfate, that depending on the concentration of Fe 2 O 3 particles in this IL the flow behavior of the mixture can change also from Newtonian to nonNewtonian shear thinning and shear thickening.…”

“…In fact, non-Newtonian behavior has been described for several AILs and PILs. [46][47][48][49][50] For example, Seddon et al 46 have shown that the alkylimidazolium tetrafluoroborate family (number of carbon atoms is typically 12) is thixotropic fluids whose viscosity decreases when increasing the shear rate. Kulkarni et al 48 have reported that the flow behavior may change from Newtonian to non-Newtonian by increasing the alkyl chain length on the cation like alkyl-methylimidazoliumbased AILs.…”

“…51 In this paper, the authors have presented information on the micellar structure changes based on rheology and freezefracture images. 51 On the basis of these papers, [49][50][51] we have also reported herein the rheological study of the selected PILs and mixtures to investigate briefly the rheological behaviors of these PILs, the impact of additions of water or acetonitrile on this property, and the formation of aggregates in these media.…”

“…[42][43][44][45] Nevertheless, non-Newtonian behaviors have already been reported for some AILs [46][47][48] 49,50 Non-Newtonian shear thinning phenomena have recently been described in several PILs by Burrell et al 50 In this paper, Burrell et al have also investigated the effect of water on this property, and they showed that by increasing the water concentration the rheological behavior of the (PIL þ water) binary system changes from non-Newtonian shear thinning, to Newtonian, to non-Newtonian shear thickening behaviors. 50 More recently, a publication of Guo and Guo reports also that ionic liquid induced structure transition of nonionic wormlike micelles composed of Tween 80 and Brij 30. 51 In this paper, the authors have presented information on the micellar structure changes based on rheology and freezefracture images.…”