scholarly journals Penentuan Resistivitas Tak-Terkompensasi Cairan Ion Berbasis Imidazol dengan Metode EIS: Pengaruh Panjang Alkil dan Perbedaan Anion

2020 ◽  
Vol 11 (2) ◽  
pp. 106-112
Author(s):  
Aep Patah ◽  
Yulia Rachmawati ◽  
Riyadini Utari ◽  
Achmad Rochliadi

Ionic liquids have interesting properties because they have several advantages compared to conventional organic solvents, such as high thermal stability, high viscosity, good solvent properties, non-flammable, and non-volatile. In electrochemistry, ionic liquids can be used as solvents without the addition of electrolytes. However, ionic liquids still have resistivity properties (uncompensated resistance), thus ohmic drop measurements are needed for a potential correction. Imidazole-based ionic liquids, which are known for their high conductivity and commonly used as a solvent, have been measured of their resistivity as a function of temperature, and type of their cations/anions. Electrochemical Impedance Spectroscopy (EIS) method was chosen to measure the resistivity of ionic liquids and Bode plot was generated for the analysis of the results. The measured resistivities of ionic liquids are in the range of 420 to 1500 ohm. It is concluded that the resistivity of the imidazole-based ionic liquid is influenced by the size of their constituent ions, the viscosity, and the resistance is decreased with increasing temperature.

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 183 ◽  
Author(s):  
Marcelo Rodríguez ◽  
Luís Ayala ◽  
Pedro Robles ◽  
Rossana Sepúlveda ◽  
David Torres ◽  
...  

The unique properties of ionic liquids (ILs) drive the growing number of novel applications in different industries. The main features of ILs are high thermal stability, recyclability, low flash point, and low vapor pressure. This study investigated pure chalcopyrite dissolution in the presence of the ionic liquid 1-butyl-3-methylimidazolium hydrogen sulfate, [BMIm]HSO4, and a bromide-like complexing agent. The proposed system was compared with acid leaching in sulfate media with the addition of chloride and bromide ions. The results demonstrated that the use of ionic liquid and bromide ions improved the chalcopyrite leaching performance. The best operational conditions were at a temperature of 90 °C, with an ionic liquid concentration of 20% and 100 g/L of bromide.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Malgorzata M. Jaworska ◽  
Andrzej Górak ◽  
Joanna Zdunek

Chitin cannot be dissolved in conventional solvents due to the strong inter- and intrasheet network of hydrogen bonds and the large number of crystalline regions. Some ionic liquids (ILs) have been suggested in the literature as possible solvents for chitin. Seven of them, all having an ethyl group as substituent in the cationic ring, have been tested in this work: [Emim][Cl], [Emim][Br], [Emim][I], [Emim][OAc], [Emim][Lact], [Epyr][I], and [EMS][BFSI]. Chitin was insoluble in [EMS][BFSI] while for all other ILs solubility was limited due to high viscosity of solutions and equilibria have not been reached. Changes in physical structure, particle size distribution, and crystallinity of recovered chitin depended on ionic liquid used. Increase in porosity was observed for chitin treated with [Emim][Cl], [Emim][I], [Emim][Br], and [Emim][Lact]; changes in particle size distribution were observed for [Emim][AcOH] and [EMS][BFSI]; increase in crystallinity was noticed for chitin treated with [Epyr][I] while decrease in crystallinity for [Emim][I] was noticed. All tested ionic liquids were reused four times and changes in FTIR spectra could be observed for each IL.


Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 80 ◽  
Author(s):  
Karolina Matuszek ◽  
Ewa Pankalla ◽  
Aleksander Grymel ◽  
Piotr Latos ◽  
Anna Chrobok

Low solubility of terephthalic acid in common solvents makes its industrial production very difficult and not environmentally benign. Ionic liquids are known for their extraordinary solvent properties, with capability to dissolve a wide variety of materials, from common solvents to cellulose, opening new possibilities to find more suitable solvents for terephthalic acid. This work presents studies on the solubility of terephthalic acid in ionic liquids, and demonstrates that terephthalic acid is soluble in ionic liquids, such as 1-ethyl-3-methylimidazolium diethylphosphate, 1-butyl-3-methylimidazolium acetate, and dialkylimidazolium chlorides up to four times higher than in DMSO. Additionally, the temperature effect and correlation of ionic liquid structure with solubility efficiency are discussed.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2611
Author(s):  
Esther Udabe ◽  
Anthony Sommers ◽  
Maria Forsyth ◽  
David Mecerreyes

Chromate free corrosion inhibitors are searched for to mitigate the economic loss caused by mid-steel corrosion. Here, we show metal-free organic inhibitors having free coumarate anions that can be used either as direct corrosion inhibitors or incorporated into a polymer coating obtained by UV-curing. Four different ionic liquid monomers and polymer coatings with hexoxycoumarate anion and different polymerizable counter cations were investigated. Potentiodynamic polarization, electrochemical impedance spectroscopy, and surface analyses have verified their corrosion inhibition performance on a mild steel AS1020 surface. In the case of the coumarate ionic liquid monomers, the most promising inhibitor is the one coupled with the ammonium cation, showing an inhibition efficiency of 99.1% in solution followed by the imidazolium, pyridinium, and anilinium. Next, the ionic liquid monomers were covalently integrated into an acrylic polymer coating by UV-photopolymerization. In this case, the barrier effect of the polymer coating is combined with the corrosion inhibitor effect of the pendant coumarate anion. Here, the best polymer coatings are those containing 20% imidazolium and pyridinium cations, presenting a greater impedance in the EIS (Electrochemical Impedance Spectroscopy) measurements and less evidence of corrosion in the scribe tests. This article shows that the cationic moiety of coumarate based ionic liquids and poly(ionic liquid)s has a significant effect on their excellent corrosion inhibition properties for a mild steel surface exposed to aqueous chloride solutions.


2021 ◽  
Author(s):  
Nicole S.M. Vieira ◽  
Margarida L. Ferreira ◽  
Paulo J. Castro ◽  
João M.M. Araújo ◽  
Ana B. Pereiro

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.


Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1227 ◽  
Author(s):  
Olga Bartlewicz ◽  
Izabela Dąbek ◽  
Anna Szymańska ◽  
Hieronim Maciejewski

This mini-review briefly describes the recent progress in the design and development of catalysts based on the presence of ionic liquids. In particular, the focus was on heterogeneous systems (supported ionic liquid (IL) phase catalysts (SILPC), solid catalysts with ILs (SCILL), porous liquids), which due to the low amounts of ionic liquids needed for their production, eliminate basic problems observed in the case of the employment of ionic liquids in homogeneous systems, such as high price, high viscosity, and efficient isolation from post-reaction mixtures.


Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 436 ◽  
Author(s):  
Qiang Xu ◽  
Wei Jiang ◽  
Jianbai Xiao ◽  
Xionghui Wei

A series of tetraglyme–sodium salt ionic liquids have been prepared and found to be promising solvents to absorb SO2. The experiments here show that [Na–tetraglyme][SCN] ionic liquid has excellent thermal stability and a 30% increase in SO2 absorption capacity compared to other sodium salt ionic liquids and the previously studied lithium salt ionic liquids in terms of molar absorption capacity. The interaction between SO2 and the ionic liquid was concluded to be physical absorption by IR and NMR.


2014 ◽  
Vol 625 ◽  
pp. 549-552 ◽  
Author(s):  
Rizwan Safdar ◽  
Abdul Aziz Omar ◽  
Lukman Ismail ◽  
Bhajan Lal

The aim of this research is to find out the potential usage of water miscible ammonium based ionic liquids (ILs) towards CO2capture. To measure the solubility of CO2in 55 wt. % aqueous solution of Tetra butyl ammonium hydroxide (TBAOH), the experiments were carried out using high pressure solubility cell. Solubilities were determined in the temperature range of (303.15 to 333.15) K by varying the pressure from (2 to 10) bar and are reported as loading capacity (mol CO2/mol TBAOH). The solubility of CO2in this aqueous IL decreased with increasing temperature and increased with increasing pressure.


2018 ◽  
Vol 42 (9) ◽  
pp. 6990-6996 ◽  
Author(s):  
Abhishek Dhar ◽  
Nadavala Siva Kumar ◽  
Mohammad Asif ◽  
Rohit L. Vekariya

A new series of pyridinium based dicationic ionic liquids was designed and synthesized. The synthesized ionic liquids have excellent thermal stability and good ionic conductivity. They can be used as electrolytes in photovoltaic devices.


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