scholarly journals A Presentation of Ionic Liquids as Lubricants: Some Critical Comments

2021 ◽  
Vol 11 (12) ◽  
pp. 5677
Author(s):  
Pietro Calandra ◽  
Elisabeta I. Szerb ◽  
Domenico Lombardo ◽  
Vincenzo Algieri ◽  
Antonio De Nino ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Electrostatic Interactions ◽  
High Viscosity ◽  
Point Of View ◽  
Added Value ◽  
Intrinsic Nature ◽  
Aggregation Pattern ◽  
New Ideas ◽  
Traditional Pattern

Ionic liquids (ILs) are liquid materials at room temperature with an ionic intrinsic nature. The electrostatic interactions therefore play a pivotal role in dictating their inner structure, which is then expected to be far from the traditional pattern of classical simple liquids. Therefore, the strength of such interactions and their long-range effects are responsible for the ionic liquid high viscosity, a fact that itself suggests their possible use as lubricants. More interestingly, the possibility to establish a wide scenario of possible interactions with solid surfaces constitutes a specific added value in this use. In this framework, the ionic liquid complex molecular structure and the huge variety of possible interactions cause a complex aggregation pattern which can depend on the presence of the solid surface itself. Although there is plenty of literature focusing on the lubricant properties of ionic liquids and their applications, the aim of this contribution is, instead, to furnish to the reader a panoramic view of this exciting problematic, commenting on interesting and speculative aspects which are sometimes neglected in standard works and trying to furnish an enriched vision of the topic. The present work constitutes an easy-to-read critical point of view which tries to interact with the imagination of readers, hopefully leading to the discovery of novel aspects and interconnections and ultimately stimulating new ideas and research.

scholarly journals Modification of Chitin Particles with Ionic Liquids Containing Ethyl Substituent in a Cation

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Malgorzata M. Jaworska ◽  
Andrzej Górak ◽  
Joanna Zdunek
Keyword(s):  
Particle Size ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Hydrogen Bonds ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
High Viscosity ◽  
Physical Structure ◽  
Ethyl Group ◽  
Network Of Hydrogen Bonds

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.

scholarly journals Heterogeneous Catalysis with the Participation of Ionic Liquids

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1227 ◽  
Author(s):  
Olga Bartlewicz ◽  
Izabela Dąbek ◽  
Anna Szymańska ◽  
Hieronim Maciejewski
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Heterogeneous Catalysis ◽  
Recent Progress ◽  
Heterogeneous Systems ◽  
High Viscosity ◽  
High Price ◽  
Solid Catalysts ◽  
Supported Ionic Liquid ◽  
Homogeneous Systems

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.

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
Keyword(s):  
Thermal Stability ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Electrochemical Impedance ◽  
High Viscosity ◽  
High Thermal Stability ◽  
Bode Plot ◽  
Ohmic Drop ◽  
Increasing Temperature ◽  
Solvent Properties

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.

scholarly journals Synthesis of cellulose graft ionic liquid using silanization reaction

2019 ◽  
Vol 22 (2) ◽  
pp. 228-234 ◽  
Author(s):  
Ut Dong THACH ◽  
Thi Lan Nhi Do ◽  
Ngoc Lan Anh Do ◽  
Minh Huy Do
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
High Performance ◽  
High Efficiency ◽  
High Capacity ◽  
High Viscosity ◽  
Batch Adsorption ◽  
Hydroxyl Groups ◽  
Base Catalyst ◽  
Low Efficiency

Introduction: Ionic liquids (ILs) have attached many attentions due to their interesting physicochemical properties. However, ionic liquids have several disadvantages including high viscosity, difficult to purify, separate and recycle, and expensive. Therefore, supported ionic liquids (SIL) have been developed to overcome these problems. SIL based on cellulose material was conventionally synthesized by silanization reaction between ionic liquid trialkoxyl silane and hydroxyl groups on the surface of cellulose. However, low reactivity of cellulose hydroxyl groups causes the low efficiency of silanization reaction. With the aim to resolve these problems and improve the reactivity of cellulose silanization reaction, cellulose graft ionic liquid was synthesized and characterized. Methods: Cellulose graft ionic liquid (CL-IL) material was synthesized by silanization reaction. The influence of reaction condition such as IL/CL (w/w) ratio, base catalyst (NH3) and agent coupling tetraethyl orthosilicate (TEOS) on silanization reaction was investigated. The modified CL-IL materials were characterized using FT-IR, TGA, SEM. The ion exchange properties were evaluated via batch adsorption studies to evidence the efficiency of silanization reaction of cellulose. Results: The study indicated that adding TEOS with NH3 catalyst could significantly increase the number of imidazolium groups grafted on cellulose about 75% compared to the conventional approach. CL-IL material is an efficient anion exchange materials displaying fast kinetic adsorption and high capacity adsorption of MO up to 1.4 mmol g-1. Conclusion: High-efficiency of cellulose silanization was obtained by using coupling agent TEOS and base catalyst. Therefore, the silanization reaction can be used for synthesis divers of functional cellulose materials. This approach can be aimed for the design of cheaper and high-performance materials for catalysis, polymer composite and adsorption in water treatment and depollution of industrial wastewater.  

scholarly journals Computational solvation analysis of biomolecules in aqueous ionic liquid mixtures

2018 ◽  
Vol 10 (3) ◽  
pp. 825-840 ◽  
Author(s):  
Veronika Zeindlhofer ◽  
Christian Schröder
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Liquid Mixtures ◽  
High Viscosity ◽  
Full Potential ◽  
New Class ◽  
Fundamental Knowledge ◽  
Structure And Dynamics ◽  
Significant Interest ◽  
The Impact

Abstract Based on their tunable properties, ionic liquids attracted significant interest to replace conventional, organic solvents in biomolecular applications. Following a Gartner cycle, the expectations on this new class of solvents dropped after the initial hype due to the high viscosity, hydrolysis, and toxicity problems as well as their high cost. Since not all possible combinations of cations and anions can be tested experimentally, fundamental knowledge on the interaction of the ionic liquid ions with water and with biomolecules is mandatory to optimize the solvation behavior, the biodegradability, and the costs of the ionic liquid. Here, we report on current computational approaches to characterize the impact of the ionic liquid ions on the structure and dynamics of the biomolecule and its solvation layer to explore the full potential of ionic liquids.

Mapping the “Extra Solvent Power, ESP” of Ionic Liquids for Monomers, Polymers and Globular Nanoparticles

2017 ◽  
Author(s):  
Jose A. Pomposo
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Linear Polymers ◽  
Green Solvents ◽  
Ionic Polymers ◽  
First Time ◽  
Solvent Power

Understanding the miscibility behavior of ionic liquid (IL) / monomer, IL / polymer and IL / nanoparticle mixtures is critical for the use of ILs as green solvents in polymerization processes, and to rationalize recent observations concerning the superior solubility of some proteins in ILs when compared to standard solvents. In this work, the most relevant results obtained in terms of a three-component Flory-Huggins theory concerning the “Extra Solvent Power, ESP” of ILs when compared to traditional non-ionic solvents for monomeric solutes (case I), linear polymers (case II) and globular nanoparticles (case III) are presented. Moreover, useful ESP maps are drawn for the first time for IL mixtures corresponding to case I, II and III. Finally, a potential pathway to improve the miscibility of non-ionic polymers in ILs is also proposed.

Dynamics of Ion Locking in Doubly Polymerized Ionic Liquids

2020 ◽  
Author(s):  
Swati Arora ◽  
Julisa Rozon ◽  
Jennifer Laaser
Keyword(s):  
Dielectric Constant ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Ion Pairs ◽  
Polymer Chains ◽  
Ion Motion ◽  
Charged Species ◽  
Broadband Dielectric Spectroscopy ◽  
Covalently Linked ◽  
Insight Into

<div>In this work, we investigate the dynamics of ion motion in “doubly-polymerized” ionic liquids (DPILs) in which both charged species of an ionic liquid are covalently linked to the same polymer chains. Broadband dielectric spectroscopy is used to characterize these materials over a broad frequency and temperature range, and their behavior is compared to that of conventional “singly-polymerized” ionic liquids (SPILs) in which only one of the charged species is attached to the polymer chains. Polymerization of the DPIL decreases the bulk ionic conductivity by four orders of magnitude relative to both SPILs. The timescales for local ionic rearrangement are similarly found to be approximately four orders of magnitude slower in the DPILs than in the SPILs, and the DPILs also have a lower static dielectric constant. These results suggest that copolymerization of the ionic monomers affects ion motion on both the bulk and the local scales, with ion pairs serving to form strong physical crosslinks between the polymer chains. This study provides quantitative insight into the energetics and timescales of ion motion that drive the phenomenon of “ion locking” currently under investigation for new classes of organic electronics.</div>

Ionic Liquid Assisted Synthesis of Some 2-Aminobenzenethiols

2019 ◽  
Vol 16 (7) ◽  
pp. 550-555
Author(s):  
Dinesh K. Jangid ◽  
Keshav L. Ameta ◽  
Surbhi Dhadda ◽  
Anjali Guleria ◽  
Prakash G. Goswami ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Comparative Study ◽  
Maximum Yield ◽  
Efficient Synthesis ◽  
Target Molecules ◽  
Presence And Absence

Ionic Liquid assisted efficient synthesis of some 2-aminobenzenethiols has been reported using three different Ionic Liquids (ILs) namely methylimidazolium tetrafluoroborate [MIM]+[BF4]−, methylimidazolium chloride [MIM]+[Cl]− and methylimidazolium nitrate [MIM]+[NO3]−. A comparative study has been carried out for the synthesis of target molecules in the presence and absence of IL, leading to conclusion that maximum yield has been observed with [MIM]+[BF4]−.

Dispersive Liquid-Liquid Microextraction Based on Ionic Liquid and Spectrophotometric Determination of Bilirubin in Biological Samples

2020 ◽  
Vol 16 (5) ◽  
pp. 652-659
Author(s):  
Asiye A. Avan ◽  
Hayati Filik
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Biological Samples ◽  
Urine Samples ◽  
Spectrophotometric Detection ◽  
Full Color ◽  
Dispersive Liquid Liquid Microextraction ◽  
Urine And Serum ◽  
Liquid Microextraction

Background: An Ionic Liquid-based based Dispersive Liquid-Liquid Microextraction (IL-DLLME) method was not applied to preconcentration and determination of bilirubin. Ionic Liquids (ILs) are new chemical compounds. In recent years, Ionic Liquids (ILs) have been employed as alternative solvents to toxic organic solvents. Due to these perfect properties, ILs have already been applied in many analytical extraction processes, presenting high extraction yield and selectivity for analytes. Methods: In this study, IL-DLLME was applied to biological samples (urine and serum) for the spectrophotometric detection of bilirubin. For bilirubin analysis, the full-color development was based on the reaction with periodate in the presence of hydrochloric acid. The high affinity of bilirubin for the ionic liquid phase gave extraction percentages above 98% in 0.3 M HCl solution. Results: Several IL-extraction parameters were optimized and room temperature ionic liquid 1-butyl- 1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and ethanol were used as extraction and disperser solution. The linear range was found in the range of 0.5-6.0 μM (0.3-3.5 μg mL-1) and the limits of detection of the proposed method was 0.5 μM (0.3 μg mL-1). The proposed method was applied for the preconcentration and separation of trace bilirubin in real urine samples. Also, the recoveries for bilirubin in spiked biological samples (urine and serum) were found to be acceptable, between 95-102%. Conclusion: The proposed IL-DLLMEapproach was employed for the enrichment and determination of trace levels of bilirubin in urine samples using NaIO4 as an oxidizing agent and Uv-vis spectrophotometric detection. The periodate oxidation of bilirubin is rapid, effective, selective, and simple to perform. The method contains only HCl, NaOI4, and an anionic surfactant. The method may be useful for economizing in the consumption of reagents in bilirubin determining. The IL-DLLMEmethod ensures a high yield and has a low toxicity no skin sensitization, no mutagenicity and no ecotoxicity in an aquatic environment since only very low quantities of an IL is required. For full-color formation, no any extra auxiliary reagents are required. Besides, the IL-DLLME technique uses a low-cost instrument such as Uv-vis which is present in most of the medical laboratories.

Analysis of the Most Valued Organization to Work for in Spain, According to Nationality and Location

2019 ◽  
Vol 5 (2) ◽  
pp. 83-99
Author(s):  
Francisco Jesús Ferreiro Seoane ◽  
Manuel Octavio Del Campo Villares
Keyword(s):  
Work Environment ◽  
Talent Management ◽  
Point Of View ◽  
Added Value ◽  
Quantitative Character ◽  
Autonomous Communities ◽  
Professional Performance ◽  
Significant Relationships ◽  
Pearson Correlations ◽  
Selection Of

Background: The objective of this article is to analyse if there are significant relationships between the most valuable companies operating in Spain regarding professional performance, according to nationality and location within their Autonomous Communities or any superior aggrupation. To do that, a sample of 100 companies has been selected. Methods: The methodology followed is based on the selection of the 100 highestvalued companies from the point of view of Human Resources’ policy for the period 2013-2016 and through the measurement of six factors: Talent Management, Retribution, Work environment, CSR, Training and Employees’ perception, and classified by nationality and location. The study was based on 12 hypotheses, using the Unifactorial Variance’s Analysis, Pearson correlations and regressions. One limitation could be the fact that this study refers to a particular period, focusing on Spain and the variables mentioned, based on questionnaires. The added value of this work lies on the newness as it has a quantitative character, and on the fact that most of the hypotheses do not comply. Results and Conclusion: This allows to deny certain beliefs that affirm that European and American companies operating in Spain are more attractive than the Spanish or the Mediterranean ones.

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