scholarly journals Electrical Conductivity and Nyquist Plot of C4C1Im BF4 at Room Temperature by Impedance Spectroscopy

2020 ◽  
Vol 3 (1) ◽  
pp. 119
Author(s):  
Pablo Vallet ◽  
Juan José Parajó ◽  
Félix Sotuela ◽  
Angel Morcillo ◽  
María Villanueva ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Electrical Conductivity ◽  
Ionic Liquids ◽  
Ionic Conductivity ◽  
Impedance Spectroscopy ◽  
Vapour Pressure ◽  
Room Temperature ◽  
Nyquist Plot ◽  
High Thermal Stability ◽  
Wide Potential

Ionic liquids (ILs) represent a real alternative for electrochemical applications due to their remarkable characteristics, namely a very low vapour pressure, low flammability, high thermal stability, wide potential window and high ionic conductivity. In this work, Nyquist plot and impedance spectroscopy at room temperature is proposed as an alternative method to obtain the ionic conductivity for ionic liquids by using an Agilent HP 4284A RLC precision meter. For this propose, the IL 1-butyl-3-methylimidazolium tetrafluoroborate (C4C1Im BF4) was selected and results were compared with the previously obtained from the conductimeter CRISON GLP31.

scholarly journals Fluorinated Ionic Liquids as Task-Specific Materials: An Overview of Current Research

2021 ◽  
Author(s):  
Nicole S.M. Vieira ◽  
Margarida L. Ferreira ◽  
Paulo J. Castro ◽  
João M.M. Araújo ◽  
Ana B. Pereiro
Keyword(s):  
Drug Delivery ◽  
Thermal Stability ◽  
Surface Tension ◽  
Ionic Liquids ◽  
Surface Activity ◽  
Vapour Pressure ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
High Thermal Stability ◽  
Gas Solubility

This chapter is focused on the massive potential and increasing interest on Fluorinated Ionic Liquids (FILs) as task-specific materials. FILs are a specific family of ionic liquids, with fluorine tags equal or longer than four carbon atoms, that share and improve the properties of both traditional ionic liquids and perfluoro surfactants. These compounds have unique properties such as three nanosegregated domains, a great surfactant power, chemical/biological inertness, easy recovery and recyclability, low surface tension, extreme surface activity, high gas solubility, negligible vapour pressure, null flammability, and high thermal stability. These properties allied to the countless possible combinations between cations and anions allow the design and development of FILs with remarkable properties to be used in specific applications. In this review, we highlight not only the unique thermophysical, surfactant and toxicological properties of these fluorinated compounds, but also their application as task-specific materials in many fields of interest, including biomedical applications, as artificial gas carries and drug delivery systems, as well as solvents for separations in engineering processes.

Ionic Liquids: A Versatile Medium for the Synthesis of Six-membered Two Nitrogen- Containing Heterocycles

2019 ◽  
Vol 23 (1) ◽  
pp. 76-96 ◽  
Author(s):  
Navjeet Kaur
Keyword(s):  
Thermal Stability ◽  
Ionic Liquids ◽  
High Activity ◽  
Organic Synthesis ◽  
Vapour Pressure ◽  
Reaction Medium ◽  
High Thermal Stability ◽  
Organic Reaction ◽  
Major Subject ◽  
The Subject

Due to special properties of ILs (ionic liquids) like their wide liquid range, good solvating ability, negligible vapour pressure, non-inflammability, environmentfriendly medium, high thermal stability, easy recycling and rate promoters etc. they are used in organic synthesis. Therefore, ionic liquids have attracted the attention of chemists and act as a catalyst and reaction medium in organic reaction with high activity. There is no doubt that ionic liquids have become a major subject of study for modern chemistry. More publications in the field have been observed each year, although there is some evidence that this is beginning to plateau at approximately 3500 papers each year. They have been the subject of several major reviews and books, dealing with different applications and aspects of their behavior. Highly efficient methods are explored for the preparation of six-membered two nitrogen-containing heterocycles with the application of IL as a catalyst and reaction medium from 1893 to 2018.

scholarly journals Effects of Substitution of Y with Yb and Ce on the Microstructures and Mechanical Properties of Mg88.5Zn5Y6.5

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Hongxin Liao ◽  
Taekyung Lee ◽  
Jiangfeng Song ◽  
Jonghyun Kim ◽  
Fusheng Pan
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Creep Resistance ◽  
Room Temperature ◽  
High Thermal Stability ◽  
Long Period ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of the Mg88.5Zn5Y6.5-XREX (RE = Yb and Ce, X = 0, 1.5, 3.0, and 4.5) (wt.%) alloys were investigated in the present study. Mg88.5Zn5Y6.5 is composed of three phases, namely, α-Mg, long-period stacking ordered (LPSO) phases, and intermetallic compounds. The content of the LPSO phases decreased with the addition of Ce and Yb, and no LPSO phases were detected in Mg88.5Zn5Y2.0Yb4.5. The alloys containing the LPSO phases possessed a stratified microstructure and exhibited excellent mechanical properties. Mg88.5Zn5Y5.0Ce1.5 exhibited the highest creep resistance and mechanical strength at both room temperature and 200 °C, owing to its suitable microstructure and high thermal stability. The yield strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature was 358 MPa. The ultimate tensile strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature and 200 °C was 453 MPa and 360 MPa, respectively.

scholarly journals Ionic Liquid Electrolytes for Safer and More Reliable Sodium Battery Systems

2020 ◽  
Vol 10 (18) ◽  
pp. 6323 ◽  
Author(s):  
Mariangela Bellusci ◽  
Elisabetta Simonetti ◽  
Massimo De Francesco ◽  
Giovanni Battista Appetecchi
Keyword(s):  
Thermal Stability ◽  
Ionic Liquid ◽  
Ionic Conductivity ◽  
Low Temperature ◽  
Room Temperature ◽  
Side Chain ◽  
Electrolyte Mixtures ◽  
Sodium Battery ◽  
Sodium Batteries ◽  
Battery Systems

Na+-conducting, binary electrolytic mixtures, based on 1-ethyl-3-methyl-imidazolium, trimethyl-butyl-ammonium, and N-alkyl-N-methyl-piperidinium ionic liquid (IL) families, were designed and investigated. The anions were selected among the per(fluoroalkylsulfonyl)imide families. Sodium bis(trifluoromethylsulfonyl)imide, NaTFSI, was selected as the salt. The NaTFSI-IL electrolytes, addressed to safer sodium battery systems, were studied and compared in terms of ionic conductivity and thermal stability as a function of the temperature, the nature of the anion and the cation aliphatic side chain length. Room temperature conductivities of interest for sodium batteries, i.e., largely overcoming 10−4 or 10−3 S cm−1, are displayed. Similar conduction values are exhibited by the EMI-based samples even below −10 °C, making these electrolyte mixtures potentially appealing also for low temperature applications. The NaTFSI-IL electrolytes, with the exception of the FSI-ones, are found to be thermally stable up to 275 °C, depending on the nature of the cation and/or anion, thus extending their applicability above 100 °C and remarkably increasing the reliability and safety of the final device, especially in the case of prolonged overheating.

scholarly journals ON/OFF Photostimulation of Isatin Bipyridyl Hydrazones: Photochemical and Spectral Study

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2668 ◽  
Author(s):  
Róbert Šandrik ◽  
Pavol Tisovský ◽  
Klaudia Csicsai ◽  
Jana Donovalová ◽  
Martin Gáplovský ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Spectral Study ◽  
Photochemical Reaction ◽  
Room Temperature ◽  
High Thermal Stability ◽  
Light Stimulation ◽  
Fluoride Ions ◽  
Isomerization Process

Four novel isatin hydrazones containing bipyridyl fragments were synthesized as potential ON/OFF switches. Hydrazone Z-isomers exhibit high thermal stability. The characteristic photochemical reaction for all studied hydrazones is the Z–E isomerization in CHCl3. After irradiation of hydrazones 1 and 2 in dimethylformamide (DMF), the photoreaction products are tautomers. When using light with the appropriate wavelength, the photo-tautomerization reaction is reversible. In these conditions, studied hydrazones have ON/OFF switch properties. In the case of hydrazones 1 and 2, by alternating heat and light stimulation it is possible to control the isomerization process reversibly. In the presence of fluoride ions, NH hydrogen from the studied hydrazones is cleaved, and the corresponding anions are formed. The resulting anions of Z-isomers are changed to the corresponding E-isomer at room temperature.

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