Effects of Polarity and Hydrogen Bonding on Physical Properties and Ion Dissociation in 1-Ethyl-3-methylimidazolium Ionic Liquid + Non-aqueous Solvent Systems

Dong

et al. 2023

Preprint

The present work designs a series of cycloalkyl ester oils and reports a comparative study on their physicochemical and tribological properties, biological toxicity and degradability. From the perspective of molecular structure, the factors affecting their physicochemical, tribological properties, biological toxicity and degradability were discussed, including steric hindrance, group polarity and so on. The results demonstrated that cycloalkyl ester oils had better thermal stability and viscidity-temperature capability than the reference oils. Additionally, their friction reducing and anti-wear performance was superior to the reference samples. Unexpectedly, the cycloalkyl ester oils were found to have higher toxicity to the experimental plants (wheat and pak choi) due to the introducing of the cycloalkyl group, which enhanced the lipophilicity of the corresponding oils and then strengthen the damaging of the oils to plant cell. Some of the cycloalkyl ester oils, on the other hand, were proved to be more biodegradable than the reference samples. On the whole, developing green lubricants by replacing aromatic rings is not entirely successful. Lubricants' biodegradability can be improved with this replacement, but their ecotoxicity cannot be reduced. Anyway, the present work provides a specific benchmark for the subsequent development of environmentally friendly, high-performance synthetic ester lubricants.

Section: Kinematic Viscosity and Viscosity Indexmentioning

confidence: 99%

WITHDRAWN: Is Replacement of Aromatic Compounds with Alkyl Ones Really the Effective Way toward Developing Greener Lubricants?

Dong

et al. 2023

Preprint

ACS Appl. Polym. Mater.

“…The maximum absorption wavelength measurements reveal significant disintegration behavior of the eutectogel in the DMSO solution due to the disruption of OH–OH hydrogen bonding in the eutectogel (Figure S16, Supporting Information). In addition to solvent polarity effects, it is found that the hydrogen bonding, primarily between the solvent and the ion, further increased the ion dissociation, in turn significantly influencing the transport behavior . However, the dissociation model would need to be enhanced considerably by developing more accurate Stokes Radii values and incorporating ion dynamics to adequately describe these complex hydrogen bonding systems .…”

Section: Resultsmentioning

confidence: 99%

Poly(vinyl alcohol)/Gelatin-Based Eutectogels for the Sensitive Strain Sensor with Recyclability and Multienvironmental Suitability

Chen

Mai

et al. 2022

Flexible gel-based strain sensors have made remarkable progress, emerging as promising candidates for wearable electronic devices. Too much attention was paid to the sensing sensitivity of the conventional gel sensors, and their environmental tolerance and green recyclability were ignored. This work designs a high ion conductive, multienvironmentally adaptable, and recyclable eutectogel, with gelatin-strengthened poly(vinyl alcohol) (PVA) and deep eutectic solvent (DES) as the gelator and disperser, respectively. Interestingly, the cross-linked network composed of PVA and gelatin polymer molecules endows the eutectogel with an ultimate tensile strength of 6.8 MPa. Moreover, the ionic liquid-like characteristic of DES at room temperature and abundant hydrogen bonds in DES can simultaneously improve the ionic conductivity (0.12 S/m) and environmental tolerance of the eutectogel. A reliable strain sensor based on this eutectogel exhibits high stability over a wide temperature range (−20∼100 °C) and harsh chemical environments (acid and base). Furthermore, this recyclable eutectogel can be easily disintegrated and regelatinized via a simple solvation–evaporation procedure, while retaining its initial mechanical and sensing performances. This study creates a candidate for applications in wearable electronic devices and sheds light on minimizing the environmental impact of other electronic wastes.

ACS Sustainable Chem. Eng.

“…They reported that this phenomenon was due to the competition between free-ion concentration and viscous forces hindering ion diffusion. 17 Existing studies offer qualitative insights into ion dissociation phenomena for a limited number of IL/solvent systems. A comprehensive theory is needed to understand how ion dissociation varies based on anion/cation size, type, and concentrations in diverse solvents.…”

Section: Investigation Of [Bmim][bf 4 ] and [Emim][bfmentioning

confidence: 99%

“…1,2 However, at an intermediate concentration range, the RTILs may undergo partial dissociation, the extent of which depends on the concentration of the RTIL and the type of solvent. 2,17 Electrolyte morphology reacts sensitively to solvent dilution, impacting the dissociation intensity and mixture properties. correlating the ionic conductivity with mixture composition over various concentrations.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Available ion dissociation studies span concentrated or dilute systems. Ions accumulate into clusters at high concentrations of RTILs, , which result in partial ionization, − whereas, at very dilute concentrations of IL in solvent systems (<1 mM), complete dissociation can be expected as the solvent screens the attractive forces between the anion and cation, , but there are exceptions. , However, at an intermediate concentration range, the RTILs may undergo partial dissociation, the extent of which depends on the concentration of the RTIL and the type of solvent. , Electrolyte morphology reacts sensitively to solvent dilution, impacting the dissociation intensity and mixture properties. A limited understanding of partial ion dissociation prompts us to explore IL/solvent electrolytes, correlating the ionic conductivity with mixture composition over various concentrations.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Theory-Enabled High-Throughput Screening of Ion Dissociation Explains Conductivity Enhancements in Diluted Ionic Liquid Mixtures

Chauhan,

Sartape,

Thorat

et al. 2023

The growing demand for room-temperature ionic liquids (RTILs) for energy applications necessitates the development of an efficient screening platform. In this study, we successfully developed a fully automated high-throughput RTIL screening platform specifically designed for assessing ionic conductivity. By utilizing the 96 wells of a microtiter plate as individual electrolysis cells, we measured the ionic conductivity of 22 different RTILs, encompassing various combinations of cations and anions, and benchmarked the values with existing literature. We also employed the screening platform to investigate the conductivities of RTIL mixtures with a nonaqueous solvent, ethylene glycol (EG). Specific combinations of RTILs with EG result in approximately 200% enhancement in the conductivity values compared to the pure RTILs. To understand the underlying mechanisms responsible for this enhancement, we developed a theoretical framework for ionic conductivity that considers factors such as the degree of dissociation, viscous forces, and molal volume of the RTIL-EG mixtures. The optimized electrolyte mixture was then employed in the migration-assisted moisture gradient (MAMG) CO 2 capture process to study the effects of improved ionic conductivity on the energy efficiency of the process. Notably, the enhanced conductivity of the RTIL-EG mixture led to a nearly 50% reduction in energy consumption for capturing CO 2 . These outcomes highlight the effectiveness of our strategy in screening RTILs and improving existing processes. Moreover, this fully automated high-throughput setup, combined with the developed theoretical framework, provides a comprehensive platform for screening and studying RTIL mixtures with different solvents, enabling their application in various fields.