| 1. |
- Gusain, Rashi, et al.
(author)
-
Thermophysical properties of trioctylalkylammonium bis(salicylato)borate ionic liquids: Effect of alkyl chain length
- 2018
-
In: Journal of Molecular Liquids. - : Elsevier. - 0167-7322 .- 1873-3166. ; 269, s. 540-546
-
Journal article (peer-reviewed)abstract
- Thermophysical properties of halogen-free ionic liquids are gaining significant attention for industrial applications. In this context, trioctylalkylammonium bis(salicylato)borate (N888n-BScB) ionic liquids having variable alkyl chain length (n = 4, 8, 12, 16) are synthesized to explore the effect of chain length and temperature on their physicochemical properties. The density (ρ), refractive index (nD), and speed of sound (u) are measured in the temperature range of 293.15 to 333.15 K. The tetraoctylammonium-BScB is found to be highly dense ionic liquid, and it was attributed to the closer packing of symmetric structure of tetraoctylammonium cation. Furthermore, derived thermodynamic properties such as isentropic compressibility (βs), coefficient of thermal expansion (α), standard entropy (S°), intermolecular free length (Lf) and lattice energy (UPOT) are calculated for the N888n-BScB ionic liquids using the experimental data and shown the effect of variable chain length. This study provides a comprehensive insight on the thermophysical properties of halogen-free ionic liquids.
|
|
| 2. |
- Kumari, Sangita, et al.
(author)
-
Octadecanethiol-grafted molybdenum disulfide nanosheets as oil-dispersible additive for reduction of friction and wear
- 2017
-
In: FlatChem. - : Elsevier. - 2452-2627. ; 3, s. 16-25
-
Journal article (peer-reviewed)abstract
- Molybdenum disulfide (MoS2) easily shears at the contact interfaces because of weak interplaner interaction and exhibits high mechanical strength, which promises its potential for tribological applications. However, poor dispersibility of MoS2 in the lube oils has been a great challenge. Herein, a facile and scalable hydrothermal approach is presented to synthesize the MoS2 nanosheets and then chemically functionalized with octadecanethiol (ODT). The structural defects and vacant sulfur sites on the Mo-atoms of MoS2 nanosheets are targeted for grafting of ODT via Mo-S dative linkage. The chemical and structural features of MoS2-ODT are characterized by FTIR, XPS, XRD and HRTEM analyses. The dispersion stability of MoS2-ODT nanosheets in the polyol ester lube oil is examined by UV–Visible spectroscopy. The van der Waals interaction between the octadecyl chain of MoS2-ODT and oleate chains of polyol ester lube oil facilitates the dispersion of MoS2-ODT nanosheets. Tribological results revealed that minute dosing (0.05 mg.mL−1) of thoroughly dispersed MoS2-ODT nanosheets, as an additive to polyol lube oil, significantly reduced the friction and the wear of steel tribo-pair. The uninterrupted supply of MoS2-ODT nanosheets on the tribo-contacts, formation of MoS2 thin film on tribo-interfaces, ease of shearing driven by weak van der Waals interaction between MoS2 lamellae and high mechanical strength of MoS2, collectively enhanced the tribo-performance, when thoroughly dispersed MoS2-ODT was used as an additive to the polyol lube base oil.
|
|
| 3. |
- Shah, Faiz Ullah, 1981-, et al.
(author)
-
Transport and Association of Ions in Lithium Battery Electrolytes Based on Glycol Ether Mixed with Halogen-Free Orthoborate Ionic Liquid
- 2017
-
In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7
-
Journal article (peer-reviewed)abstract
- Ion transport behaviour of halogen-free hybrid electrolytes for lithium-ion batteries based on phosphonium bis(salicylato)borate [P4,4,4,8][BScB] ionic liquid mixed with diethylene glycol dibutyl ether (DEGDBE) is investigated. The Li[BScB] salt is dissolved at different concentrations in the range from 0.15 mol kg−1 to 1.0 mol kg−1 in a mixture of [P4,4,4,8][BScB] and DEGDBE in 1:5 molar ratio. The ion transport properties of the resulting electrolytes are investigated using viscosity, electrical impedance spectroscopy and pulsed-Field Gradient (PFG) NMR. The apparent transfer numbers of ions are calculated from the diffusion coefficients measured by using PFG NMR. PFG NMR data suggested ion association upon addition of Li salt to the [P4,4,4,8][BScB] in DEGDBE solution. This is further confirmed by liquid state 7Li and 11B NMR, and FTIR spectroscopic techniques, which suggest strong interactions between the lithium cation and oxygen atoms of the [BScB]− anion in the hybrid electrolytes.
|
|
