Viscosity of aqueous ionic liquids analogues as a function of water content and temperature

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 tool 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 informa- tion presented in this work on the viscosity of aqueous DES solutions may 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.

Removal of Basic Nitrogen Compounds from Coker Diesel by Eutectic Ionic Liquid

The eutectic ionic liquid （EIL） tetraethyl ammonium bromide-malonic acid （TEAB-Mal） was synthesized, with its structure characterized by the FT-IR spectroscopy and the 1H NMR spectrometry. The performance for removal of basic nitrogen compounds by EIL was studied using coker diesel as the feedstock. Experimental results showed that the EIL （TEAB-Mal） exhibited a good denitrogenation performance, leading to a 93.6% of basic N-removal efficiency under reaction conditions covering： a temperature of 30 ℃, an EIL to oil mass ratio of 1：1, an extraction time of 30 min, and a settling time of 120 min, while the basic nitrogen content in diesel dropped from 580 μg/g to 37 gg/g. In addition, the efficiency for extraction of basic N-compounds could still reach 62.9% at am EIL/oil mass ratio of 1：7 after four recycles of the EIL.

Molar volume of eutectic solvents as a function of molar composition and temperature

The conventional Rackett model for predicting liquid molar volume has been modified to cater for the effect of molar composition of the Deep Eutectic Solvents(DES). The experimental molar volume data for a group of commonly used DES has been used for optimizing the improved model. The data involved different molar compositions of each DES. The validation of the new model was performed on another set of DESs. The average relative deviation of the model on the training and validation datasets was approximately 0.1% while the Rackett model gave a relative deviation of more than 1.6%. The modified model deals with variations in DES molar composition and temperature in a more consistent way than the original Rackett model which exhibits monotonic performance degradation as temperature moves away from reference conditions. Having the composition of the DES as a model variable enhances the practical utilization of the predicting model in diverse design and process simulation applications.

Novel manganese(Ⅱ)-based deep eutectic solvents: Synthesis and physical properties analysis

Type IV deep eutectic solvent（DES） involves the formation of metal-based eutectics from metal salts or metal salt hydrate in combination with various hydrogen-bond donors（HBDs） such as urea, ethylene glycol or acetamide. In current study, two distinguished approaches were used to synthesize potential DESs, given as the direct heating and the evaporating methods. Successful synthesized DESs were subjected for physical properties characterization by Fourier Transform Infrared（FTIR） Spectroscopy, thermal stability, viscosity,and conductivity analyses. Five novel manganese（II）-based DESs were successfully synthesized as reported in this study. Data obtained indicated that the Mn Cl2á4H2Oáacetamide DES exhibits the lowest freezing point（27.5℃）, highest thermal stability（193℃ point of dehydration）, lowest viscosity（E = 112.8cP） and the highest conductivity（0.12723 mS/cm）. The findings obtained reveal the characteristics, nature or features of synthesized DESs as potential industrial solvents.