scholarly journals The physicochemical properties of the deep eutectic solvents with triethanolamine as a major component

2020 ◽  
Vol 85 (10) ◽  
pp. 1303-1315
Author(s):  
Biljana Djordjevic ◽  
Dragan Troter ◽  
Vlada Veljkovic ◽  
Mirjana Kijevcanin ◽  
Ivona Radovic ◽  
...  

Different deep eutectic solvents (DESs) of triethanolamine (TEOA) and oxalic acid (OA), glacial acetic acid (AA), L-(+)-lactic acid (LA), oleic acid (OLA), glycerol (G), ethylene glycol (EG), propylene glycol (PEG), choline chloride (ChCl) or 1,3-dimethylurea (DMU) were prepared and characterized regarding their physicochemical (density, viscosity, electrical conductivity, refractive index, coefficient of volume expansion, molecular volume, lattice energy and heat capacity) properties over the temperature range of 293.15?363.15 K at 101.325 kPa. For all tested DESs, the density, viscosity and refractive index decreased with rising temperature, while the electrical conductivity increased. The temperature dependence of viscosity and electrical conductivity are described by the Vogel?Tamman?Fulcher equations. The viscosity and molar conductivity, which exhibited a linear behaviour, were correlated by the fractional Walden rule. Besides, the Fourier transform infrared spectroscopy (FTIR) was used to study the functional groups of these DESs while thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) provided the information about their stability. The tested DESs of TEOA possess desirable properties for use in various industrial processes, such as extractions, separations, chemical technology and biotechnology.

2017 ◽  
Vol 82 (9) ◽  
pp. 1039-1052 ◽  
Author(s):  
Dragan Troter ◽  
Zoran Todorovic ◽  
Dusica Djokic-Stojanovic ◽  
Biljana Djordjevic ◽  
Vanja Todorovic ◽  
...  

This paper reports the physicochemical (density, dynamic viscosity, electrical conductivity and refractive index) and the thermodynamic (thermal expansion coefficient, molecular volume, lattice energy and heat capacity) properties of several choline chloride (ChCl) based deep eutectic solvents (DESs), with 1:2 mole ratio, respectively: ChCl:propylene glycol, ChCl:1,3-dimethylurea and ChCl:thiourea, at atmospheric pressure as a function of temperature over the range of 293.15?363.15 K. Their properties were also compared with those of some already characterized ChCl-based DESs, namely ChCl:ethylene glycol, ChCl:glycerol and ChCl:urea (1:2 mole ratio). Density, viscosity and refractive index of all DESs decrease with the increasing temperature while the electrical conductivity increases. Viscosity and conductivity of the tested DESs were fitted by both Arrhenius-type and Vogel?Tamman?Fulcher equations. The changes of molar enthalpy, entropy and Gibbs energy of activation, determined using the Eyring theory, demonstrated the interactional factor as predominant over the structural factor for all DES systems. The fractional Walden rule, used to correlate molar conductivity and viscosity, showed an excellent linear behaviour. It was shown that ChCl:propylene glycol DES had properties similar to ChCl:ethylene glycol and ChCl:glycerol DESs. However, the properties (density, viscosity and electrical conductivity) of ChCl:1,3-dimethylurea and ChCl: :thiourea DESs were inferior to those of the ChCl:urea DES.


2015 ◽  
Vol 31 (8) ◽  
pp. 1468-1473 ◽  
Author(s):  
Hong-Zhen. SU ◽  
◽  
Jing-Mei. YIN ◽  
Qing-Shan. LIU ◽  
Chang-Ping. LI ◽  
...  

2020 ◽  
Vol 92 (1) ◽  
pp. 10901
Author(s):  
Saloua El Asri ◽  
Hamid Ahamdane ◽  
Lahoucine Hajji ◽  
Mohamed El Hadri ◽  
Moulay Ahmed El Idrissi Raghni ◽  
...  

Forsterite single phase powder Mg2SiO4 was synthesized by sol–gel method alongside with heat treatment, using two different cation alkaline salts MCl as mineralizers (M = Na, K) with various mass percentages (2.5, 5, 7.5, and 10 wt.%). In this work, we report on the effect of the cation type and the added amount of used mineralizer on microstructure and electrical conductivity of Mg2SiO4. The formation of forsterite started at 680–740  °C and at 630–700  °C with KCl and NaCl respectively, as shown by TG-DTA and confirmed by XRD. Furthermore, the Fourier transform infrared (FTIR) transmission spectra indicated bands corresponding to vibrations of forsterite structure. The morphology and elemental composition of sintered ceramics were examined by SEM-EDX analyses, while their densities, which were measured by Archimedes method, increased with addition of both alkaline salts. The electrical measurements were performed by Complex Impedance Spectroscopy. The results showed that electrical conductivity increased with the addition of both mineralizers, which was higher for samples prepared with NaCl than those prepared with KCl.


2021 ◽  
Vol 332 ◽  
pp. 115843
Author(s):  
Aboozar Khajeh ◽  
Khalil Parvaneh ◽  
Mehdi Shakourian-Fard

Soft Matter ◽  
2021 ◽  
Author(s):  
Meng Sun ◽  
Qintang Li ◽  
Xiao Chen

Luminescent gels have been successfully fabricated through the self-assembly of sodium cholate and a europium ion in choline chloride-based deep eutectic solvents.


2021 ◽  
Vol 23 (3) ◽  
pp. 1300-1311 ◽  
Author(s):  
Dasom Jung ◽  
Jae Back Jung ◽  
Seulgi Kang ◽  
Ke Li ◽  
Inseon Hwang ◽  
...  

The in vitro and in vivo studies suggest that choline chloride-based deep eutectic solvents may not be considered as pure, safe mixtures even if they consist of safe compounds.


2020 ◽  
Vol 32 (4) ◽  
pp. 733-738 ◽  
Author(s):  
R. Manurung ◽  
Taslim ◽  
A.G.A. Siregar

Deep eutectic solvents (DESs) have numerous potential applications as cosolvents. In this study, use of DES as organic solvents for enzymatic biodiesel production from degumming palm oil (DPO) was investigated. Deep eutectic solvent was synthesized using choline chloride salt (ChCl) compounds with glycerol and 1,2-propanediol. Deep eutectic solvent was characterized by viscosity, density, pH and freezing values, which were tested for effectiveness by enzymatic reactions for the production of palm biodiesel with raw materials DPO. Deep eutectic solvent of ChCl and glycerol produced the highest biodiesel yield (98.98%); weight of DES was only 0.5 % of that of the oil. In addition, the use of DES maintained the activity and stability of novozym enzymes, which was assessed as the yield until the 6th usage, which was 95.07 % biodiesel yield compared with the yield without using DES. Hence, using DES, glycerol in enzymatic biodiesel production had high potentiality as an organic solvent for palm oil biodiesel production


2021 ◽  
pp. 116928
Author(s):  
Jie Zhu ◽  
Hui Shao ◽  
Lin Feng ◽  
Yingzhou Lu ◽  
Hong Meng ◽  
...  

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 247
Author(s):  
Aida Albu ◽  
Cristina-Gabriela Radu-Rusu ◽  
Ioan Mircea Pop ◽  
Gabriela Frunza ◽  
Gherasim Nacu

Romania is known among the main European honey producers, due to the variety of landforms as well as the diversity of the flora. Thirty-four honey samples of the acacia, linden and multifloral types, produced in eastern Romania and collected during 2013–2018, were physico-chemically analyzed using methods provided by the national and EU standards. The results of water-insoluble solids, color and refractive index were found to be 0.023–0.131%, 0.3–76.4 mm Pfund and 1.485–1.499, respectively. The moisture content ranged between 15.20% and 20.77%, solid substances content ranged between 79.23% and 84.80% and total soluble substances content ranged between 77.83 °Brix and 83.26 °Brix. The obtained values of specific gravity were from 1.414 to 1.450 g/cm3, pH ranged from 3.673 to 5.503 and free acidity ranged between 2.4 meq and 50 meq kg−1. The ash content and the electrical conductivity varied between 0.030 and 0.543% and 130 and 679 µS cm−1, respectively. Pearsonʹs correlation analysis showed an intense association of the ash content with electrical conductivity (r = 0.81). Our findings reveal the qualitative level of Romanian honey and the variation in quality parameters due to factors such as geographical region, climatic conditions, botanical origin and handling or storage conditions.


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