22113-86-6Relevant articles and documents
Structure-energy relations in hen egg white lysozyme observed during refolding from a quenched unfolded state
Cho, Theresa Y.,Byrne, Nolene,Moore, David J.,Pethica, Brian A.,Austen Angell,Debenedetti, Pablo G.
, p. 4441 - 4443 (2009)
We use infrared spectroscopy to study the evolution of protein folding intermediate structures on arbitrarily slow time scales by rapidly quenching thermally unfolded hen egg white lysozyme in a glassy matrix, followed by reheating of the protein to refold; upon comparison with differential scanning calorimetric experiments, low-temperature structural changes that precede the formation of energetic native contacts are revealed. The Royal Society of Chemistry 2009.
Volumetric properties of ethylammonium nitrate + γ-butyrolactone binary systems: Solvation phenomena from density and raman spectroscopy
Zarrougui, Ramzi,Dhahbi, Mahmoud,Lemordant, Daniel
, p. 1531 - 1548 (2010)
The densities of binary mixtures of ethylammonium nitrate (EAN) ionic liquid (IL) and γ-butyrolactone (BL) have been measured over the entire range of concentrations at 293.15, 298.15, 303.15, 308.15, 313.15 and 318.15 K and under ambient pressure. Experimental densities were used to calculate excess molar volumes VmE, isobaric and excess isobaric expansion coefficients α and α E. The excess molar volumes have both negative and positive values, while the excess isobaric expansion coefficients are negative over the entire composition range. The V mE values have been fitted to the Redlich-Kister polynomial equation, and other volumetric properties such as the partial molar volumes V mi, the excess partial molar volume Vmi E and the partial molar volumes at infinite dilution V miE were calculated. The results have been interpreted in terms of dipole-dipole interactions, hydrogen bonds formation and structural factors of these mixtures. The FT-Raman spectroscopy study of the intensity variations of some characteristic bands such as the C=O stretching band at 1763 cm-1, C-O symmetric stretching band at 932 cm-1 and C-C stretching band at 872 cm-1 of BL has been undertaken. The solvation phenomenon is evidenced by the modifications of these band intensities due to the presence of the IL ions. Moreover, the Raman spectroscopy corroborates the volumetric study. The average number of BL molecules in the primary solvation shell of the ethylammonium cation lies between 3 and 4 depending on the temperature.
Measurements and correlation of viscosity and conductivity for the mixtures of ethylammonium nitrate with organic solvents
Litaeim, Yousra,Dhahbi, Mahmoud
, p. 42 - 50 (2010)
Transport physicochemical properties of binary mixtures ionic liquid/organic solvent (IL/OS) were studied. Systematical measurements of viscosities (η) and conductivities (Λ) for the binary mixtures of ethylammonium nitrate (EAN) with different OS, over the whole composition range and at temperature ranging from 273.15 K to 313.15 K, were performed. The variation tendency of viscosities/conductivities with composition of the mixtures was explained through the disruption of molecular solutes to ionic association or aggregation of the ionic liquids and correlation between them is carried out by means of Walden product (W). A semi-empirical equation proposed by Jones and Dole was used to describe the variation of viscosity with salt concentration (C). At low concentration of EAN, molar conductivity follows cube root law predicted by the quasi-lattice model. The two transport processes are well described by Arrhenius type laws from which the activation energies for the viscosity (Ea,η) and conductivity (Ea,Λ) are deduced.
Anhydrous proton exchange membranes at elevated temperatures: Effect of protic ionic liquids and crosslinker on proton conductivity
Yang, Yi,Gao, Hejun,Zheng, Liqiang
, p. 17683 - 17689 (2015)
A series of novel anhydrous proton exchange membranes (poly(vinyl alcohol)-citric acid-ionic liquid (PVA-CA-IL)) were prepared using the low cost ionic liquids ethylammonium nitrate (EAN), diethylammonium nitrate (DEAN), and triethylammonium nitrate (TEAN) as conductive fillers in PVA support membrane. The properties of the PVA-CA-IL membranes can be controlled by changing the molar ratio of the PVA, ILs and CA. The thermal stability of PVA-CA-IL membrane was measured by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and the microstructure was investigated using scanning electron microscopy (SEM) and the Anton-paar SAX Sess mc2 system (SAXS). The effects of temperature, ILs and crosslinker dosage on proton conductivity were also systematically investigated. The results showed that the PVA-CA-IL membranes had excellent performance. The proton conductivity of PVA-CA-EAN (mole ratio = 1:0.05:0.4) could reach up to 7.8 mS cm-1 at 140 °C. The introduction of ionic liquid into PVA membrane constituted a new and efficient kind of anhydrous proton exchange membrane. This journal is
First fluorinated zwitterionic micelle with unusually slow exchange in an ionic liquid
Wang, Xiaolin,Long, Panfeng,Dong, Shuli,Hao, Jingcheng
, p. 14380 - 14385 (2013)
The micellization of a fluorinated zwitterionic surfactant in ethylammonium nitrate (EAN) was investigated. The freeze-fracture transmission electron microscope (FF-TEM) observations confirm the formation of spherical micelles with the average diameter 25.45 ± 3.74 nm. The micellization is an entropy-driven process at low temperature but an enthalpy-driven process at high temperature. Two sets of 19F NMR signals above the critical micelle concentration (cmc) indicate that the unusually slow exchange between micelles and monomers exists in ionic liquid; meanwhile, surfactant molecules are more inclined to stay in micelle states instead of monomer states at higher concentration. Through the analysis of the half line width (Δν 1/2), we can obtain the kinetic information of fluorinated zwitterionic micellization in an ionic liquid.
Cytotoxicity of protic ionic liquids towards the HaCat cell line derived from human skin
Abraham, Amanda N.,Arunkumar, Radhika,Drummond, Calum J.,Greaves, Tamar L.,Shukla, Ravi
, (2020/07/03)
In this work we have investigated the toxicity of 10 PILs, consisting of ethyl-, ethanol-, diethanol- and triethanolammonium cations paired with nitrate, formate, acetate and glycolate anions. Their toxicity was quantified by the EC50 values of each of these PILs towards HaCat cells, which are derived from human skin cells. Additional salts and solvents were used for comparison including DMSO, choline chloride, potassium nitrate, sodium acetate and ethanol to distinguish if the toxicity changes were due to ionicity, short chain amphiphilic behaviour, or specific ion effects. The toxicity followed the general trend of choline chloride acetate containing PILs DMSO sodium acetate ethanol nitrate containing PILs or salt. Ethanolammonium acetate and ethylammonium acetate were identified as having the lowest toxicities of the PILs, being slightly more toxic than choline chloride or DMSO. Overall the toxicity was found to be highly dependent on the cation and anion combination, with the anion having a stronger affect. It was evident that the PILs can be tailored to vary their toxicities, and this is expected to be dependent on which cell lines are used.
Protic ionic liquids as catalysts for a three-component coupling/hydroarylation/dehydrogenation tandem reaction
Muntzeck, Maren,Wilhelm, René
, p. 515 - 519 (2018/06/18)
Protic ionic liquids with nitrate anions were used as solvents and catalysts for a three-component oxidative dehydrogenation tandem reaction via the coupling and hydroarylation of benzaldehyde, aniline, and phenylacetylene to a quinoline derivative. The reaction was supported by air and microwave irradiation. The presence of nitrate as counter anion in the protic ionic liquids was essential for the reaction.