Ionic liquids analogues known as Deep Eutectic Solvents (DESs) are gaining a surge of interest by the scientific community

and many applications involving DESs have been realized.Moisture content is one of the important factors that affects the physical and chemical characteristics of these fluids. In this work

the effect of mixing water with three common type Ⅲ DESs on their viscosity was investigated within the water mol fraction range of (0-1) and at the temperature range (298.15-353.15 K). Similar trends of viscosity variation with respect to molar composition and temperature were observed for the three studied systems. Due to the asymmetric geometry of the constituting molecules in these fluids

their viscosity could not be modeled effectively by the conventional Grunberg and Nissan model

and the Fang-He model was used to address this issue with excellent performance. All studied aqueous DES mixtures showed negative deviation in viscosity as compared to ideal mixtures. The degree of intermolecular interactions with water reaches a maximum at a composition of 30% aqueous DES solution. Reline

the most studied DES in the literature

showed the highest deviation. The information presented in thiswork on the viscosity of aqueous DES solutionsmay serve in tuning this important property for diverse industrial applications involving these novel fluids in fluid flow

chemical reactions

liquid-liquid separation and many more.