Display omitted
•COSMO-RS calculations performed over more than 36,000 ILs.•Experiments show a strong correlation between PS solubility and battery performance.•Machine learning models developed ...using experiment-guided target solubility limits.•XGBoost models successfully predict the PS solubility and IL properties.•ARM and feature importance analysis show that anion descriptors are more dominant.
The polysulfide (PS) shuttle mechanism (PSM) is one of the most significant challenges of lithium-sulfur (Li-S) batteries in achieving high capacity and cyclability. One way to minimize the shuttle effect is to limit the PS solubilities in the battery electrolyte. Ionic liquids (IL) are particularly suited as electrolyte solvents because of their tunable physical and chemical properties. In this work, thousands of ILs are screened to narrow down potentially viable candidates to be used as electrolytes in Li-S batteries. To that end, the COnductor-like Screening Model for Realistic Solvents (COSMO-RS) calculations are performed over more than 36,000 ILs. An extensive database containing PS solubilities and other relevant properties is constructed at 25 °C. First, the effectiveness of the COSMO-RS calculations is experimentally tested with six different ILs having a wide range of solubility and viscosity values; a strong correlation between the PS solubility and battery performance is obtained. After specifying the target limits for promising ILs using the experimental battery performance data, machine learning (ML) tools are used to predict and identify the relationship between IL properties and PS solubilities and structural and molecular descriptors of ILs. The extreme gradient boosting (XGBoost) method successfully predicts the solubility and property values. Association rule mining (ARM) and the feature importance analysis show that anion descriptors are more dominant, whereas cations have less impact on the solubilities and properties of ILs. Finally, the imidazolium and pyridinium ILs with bis_imide and borate anion groups are identified as the most promising ones.
A new method for integrated ionic liquid (IL) and absorption process design is proposed where a rigorous rate‐based process model is used to incorporate absorption thermodynamics and kinetics. ...Different types of models including group contribution models and thermodynamic models are employed to predict the process‐relevant physical, kinetic, and thermodynamic (gas solubility) properties of ILs. Combining the property models with process models, the integrated IL and process design problem is formulated as an MINLP optimization problem. Unfortunately, due to the model complexity, the problem is prone to convergence failure. To lower the computational difficulty, tractable surrogate models are used to replace the complex thermodynamic models while maintaining the prediction accuracy. This provides an opportunity to find the global optimum for the integrated design problem. A pre‐combustion carbon capture case study is provided to demonstrate the applicability of the method. The obtained global optimum saves 14.8% cost compared with the Selexol process.
Display omitted
•The IL-based advanced porous organic HCPs for CO2 capture and conversion are reviewed.•The structures, synthesis, and physical properties of ILHCPs are collected and ...discussed.•Structures and IL-moieties contents of ILHCPs are highlighted for designing CO2-philic sorbents.•Further investigations on CO2 capture and conversion by ILHCPs are required.
Ionic liquids (ILs) and hyper-crosslinked polymers (HCPs) have attracted many attentions as tunable sorbents and catalysts owing to their unique properties. Their composites, ionic liquid‐based hyper-crosslinked polymers (ILHCPs), with predesignable structures and customizable functionalities, have a promising development since 2015. However, reviews regarding the composites of ILs and HCPs have not been reported, especially based on the viewpoint of ILs. This critical review summarizes the synthetic strategies based on the synthesis of ILs and HCPs, and the types of structures of ILHCPs as well as their future synthesis directions are proposed for the first time. The detail information including physical properties and CO2 capture capacities of these ILHCPs are summarized to obtain the general relationships for further designing the efficient ILHCPs adsorbents. Furthermore, CO2 conversions into value-added chemicals via (1) N-formylation of N-methylaniline and (2) cycloaddition of epoxide are briefly introduced. Moreover, this review briefly highlights the opportunities and challenges faced by rapidly developing but still in the early stage of ILHCPs. It is expected that this article will play a role in “Turning Bricks into Jade” in the fields of advanced functional materials for CO2 capture and conversion.
Due to their distinctive properties, ionic liquids have attracted the great and unflagging interest of researchers for over 30 years. This interest has been focused mainly on their use as a green ...alternative to volatile organic solvents. However, they often act not only as solvents but also as catalysts, catalyst immobilizers and initiators. Over 100 types of chemical reactions are known in which ionic liquids (ILs) were applied successfully. This Special Issue is aimed at showing the most recent advances and trends in the design, synthesis and characterization of catalysts based on ILs, as well as presenting their activity and application potential.
Display omitted
•Cytotoxicity of 10 mono- and dicationic pyridinium-based ILs was evaluated.•HeLa, MCF-7, BGM and EA.hy926 cells were used with dicationic ILs for the first time.•Dicationic ILs have ...lower cytotoxic effect than their monocationic counterparts.•IL cytotoxicity is highly dependent on the cell type.•HeLa cells exposed to C12PyrBr died by an apoptotic mechanism.
Dicationic ionic liquids (ILs) generally possess higher thermal and electrochemical stability than the analogous monocationic ILs, which makes them more suitable for high-temperature applications as solvents for organic reactions, lubricants or stationary phase in gas chromatography. However, knowledge on dicationic IL cytotoxicity is still scarce. Here we explore the cytotoxicity of twelve mono- and dicationic pyridinium-based ILs on HeLa, MCF-7, BGM and EA.hy926 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell cycle arrest assays, apoptosis experiments and orange staining were carried out. The results showed that dicationic ILs are generally less cytotoxic than their monocationic counterparts. In monocationic ILs, cytotoxicity was stronger when they contain long alkyl chains, because of their higher lipophilicity. However, the full effect of the length of the linkage alkyl chain of dicationic ILs on cytotoxicity is not clear probably because the chain is “trapped” between both cationic moieties. IL cytotoxicity is highly dependent on the cell type, and HeLa cells exposed to C12PyrBr die via apoptosis. The present study increases our knowledge of IL cytotoxicity on human and monkey cells and clarifies the cell death mechanism. The results suggest that dicationic ILs offer the potential to replace some monocationic ILs because of their lower cytotoxicity.
In this work we have demonstrated how to prepare a novel gel polymer electrolyte (GPE) with remarkable adhesive characteristics by combining a synthesized poly(ionic liquid) consisting of ...poly(1-vinyl-3-propylimidazolium bis(fluorosulfonyl)imide) (poly(VPIFSI)) and a commercial ionic liquid: 1-ethyl-3-methyl imidazolium bis(fluorosulfonyl)imide (EMIFSI). For this purpose several PIL/IL-GPEs systems (considering the amount of IL) were subjected to electrochemical characterization. The influence of the PIL/IL-GPE (50 wt% of IL) on the properties of a flexible solid state supercapacitor was evaluated using electrochemical impedance spectroscopy, cyclic voltammetry and the galvanostatic charge/discharge technique that allows synchronous measurements of the cell voltage and the potential of the positive and negative electrodes. The influence of the ions on the formation of the electric double layer in the device during cycling employing different conditions and folding angles is discussed. The properties of the adhesive PIL/IL-GPE, such as high conductivity, good interaction between the PIL matrix and the IL liquid phase that prevents any leakage (thereby contributing to greater safety) together with the good adherability and wettability of the gel electrolyte on the electrode surface have produced a device with an improved rate capability and cyclability that undergoes hardly any changes in Csp,cell, Ereal, and Preal of the cell when folded.
Display omitted
•A novel PIL/IL-GPE with remarkable adhesive characteristics has been developed.•The performance of the PIL/IL-GPE was tested in a flexible supercapacitor (SC).•PIL/IL GPE supercapacitor was studied using galvanostatic synchronous measurements.•The PIL/IL GPE led to a device with an improved rate capability and cyclability.•The SC showed no significant changes in Csp, Ereal and Preal when the cell was folded.
Supported ionic liquid phases offer several advantages related with catalysis. Immobilization of ionic liquid on the solid support provides catalytic activity or efficient matrix for active phases, ...as enzymes or metal compounds. Ionic liquid can be physically adsorbed on the carrier (supported ionic liquid phase) or chemically grafted to the material surface (supported ionic liquid-like phase). The use of supported ionic liquid phases improves mass transport, reduces ionic amount in the process and, most importantly, enables effortless catalyst separation and recycling. Moreover, chemical modification of the surface material with ionic liquid prevents its leaching, enhancing length of catalyst life. Silica-based materials have become an effective and powerful matrix for supported ionic liquid-like phase due to its cost-efficiency, presence of hydroxyl groups on the surface enabling its functionalization, and specific material properties, such as the size and shapes of the pores. For these reasons, supported ionic liquid-like phase silica-based materials are successfully used in the organic catalysis.
•One-step method was proposed to fabricate concentration gradient CSEs for LMBs.•Gravity was used to develop a multifunctional monolayer without adding resistance.•MD simulation reveals distinct Li+ ...transport mechanisms on each side of the CSE.•The SCE displays 2300-hour stability and compatibility with high-voltage cathodes.
Multilayer composite solid electrolytes (CSEs) exhibit many advantages over uniform monolayer CSEs but are hindered by high interlayer resistance and complex preparation methods. Herein, for the first time, a natural sedimentation strategy was developed to construct concentration gradient CSEs (GCSEs) for lithium-metal batteries (LMBs). This method utilizes intrinsic gravity and photopolymerization to achieve multiple functions in the monolayer, avoiding additional interlayer resistance and reducing preparation time. Owning to the concentration gradient structure, the Li+ transport on the PolyIL-rich side relies on the weak solvation of Li+ with EMIMTFSI, while the Li+ transport on the LLZTO-rich side follows the 'vehicular diffusion' mechanism with the aid of TFSI−, improving the Li+ transport and enhances the Li+ transference number, leading to the high stability to 2300 h for the Li//Li cell and stable operation at 4.3 V with 89.6 % capacity retention after 100 cycles for the assembled LMB. Moreover, compared with the monolayer uniform hybrid CSEs, the gradient structure alleviates uncoordinated thermal expansion between LLZTO and PolyIL, avoiding stress increase during cycling and battery capacity fade. This gradient strategy mitigates high interlayer resistance and offers a universal path to address the sluggish Li+ transportation in multilayer CSEs and improves compatibility between the electrolyte and electrodes in fabricating solid-state batteries.
•Interaction of biomass with ionic liquid (IL) pretreatment studied by XRD.•Swelling and dissolution of cellulose control the resultant crystalline structure.•Proper manipulation of IL’s swelling ...ability leds to low-order structures.
X-ray diffraction (XRD) was used to understand the interactions of cellulose in lignocellulosic biomass with ionic liquids (ILs). The experiment was designed in such a way that the process of swelling and solubilization of crystalline cellulose in plant cell walls was followed by XRD. Three different feedstocks, switchgrass, corn stover and rice husk, were pretreated using 1-butyl-3-methylimidazolium acetate (C4mimOAc) at temperatures of 50–130°C for 6h. At a 5wt.% biomass loading, increasing pretreatment temperature led to a drop in biomass crystallinity index (CrI), which was due to swelling of crystalline cellulose. After most of the crystalline cellulose was swollen with IL molecules, a low-order structure was found in the pretreated samples. Upon further increasing temperature, cellulose II structure started to form in the pretreated biomass samples as a result of solubilization of cellulose in C4mimOAc and subsequent regeneration.
PDF
