Atomic force microscopy probing interactions and microstructures of ionic liquids at solid surfaces

Abstract

Ionic liquids (ILs) are room temperature molten salts that possess preeminent physicochemical properties and have shown great potential in many applications. However, the use of ILs in surface-dependent processes, e.g....

Microstructural probing of phosphonium-based ionic liquids on a gold electrode using colloid probe AFM

“…A steeper increase (green and pink lines in Fig. 6) in the force steps of [P 6,6,6,14 ][BScB] than [P 4,4,4,8 ][BScB] suggests a decreased compressibility in the ion layers 54,55 of the longer [P 6,6,6,14 ][BScB]. The observed less compressive ion layers in [P 6,6,6,14 ][BScB] is in accordance with the stiffer and more ordered ion layers of [P 6,6,6,14 ][BScB] detected by the contact resonance frequency as shown in Fig.…”

“…A steeper increase (green and pink lines in Fig. 6) in the force steps of [P 6,6,6,14 ][BScB] than [P 4,4,4,8 ][BScB] suggests a decreased compressibility in the ion layers 54,55 detected by the contact resonance frequency as shown in Fig. 5(a).…”

Immobilizing Ionic Liquids onto Functionalized Surfaces for Sensing Volatile Organic Compounds

“…The amount of adsorptive gaseous molecules is governed mainly by the surface properties for the thin interfacial ion layers of the IL film with a thickness < 10 nm. , Especially, the near-surface structuring ion layers of ILs were previously found to play a determinant role in the gaseous adsorption , and even the magnitude of the nanoscale friction. ,, Note that a smaller friction of the IL layer suggests a higher ionic mobility, which is beneficial to the faster gaseous mass transfer. , Thus, this work focuses on the gaseous sensing and adsorptive behavior of the structuring IL layers near the functionalized surfaces (thickness < 10 nm). The IL is diluted with ethanol not for controlling the bulk thickness of the IL layer but for decreasing the IL viscosity to facilitate its better immobilization with less amounts of the IL.…”

“…50,51 Especially, the near-surface structuring ion layers of ILs were previously found to play a determinant role in the gaseous adsorption 6,50 and even the magnitude of the nanoscale friction. 49,57,58 Note that a smaller friction of the IL layer suggests a higher ionic mobility, which is beneficial to the faster gaseous mass transfer. 21,22 Thus, this work focuses on the gaseous sensing and adsorptive behavior of the structuring IL layers near the functionalized surfaces (thickness < 10 nm).…”

Monitoring of the voltage-induced microstructure of C12mimBr ionic liquids on a HOPG surface usingin situXAFS

“…An et al also reported that the microstructures of ILs on solid surfaces are controlled by interactions including coulombic, van der Waals and solvophobic interactions between ILs and solid materials. 14 Bordes et al reported that the presence of large alkyl side-chains in the cations increases the ordering of ions on a graphite surface. 15 Sakka et al studied the effect of the length of alkyl chains on a electric double-layer structure using MD simulations and found that the difference in the number of butyl chains affects the composition of the first ionic layer and the orientation of butyl chains.…”