Poly(1-vinyl-1,2,4-triazolium) poly(ionic liquid)s: synthesis and the unique behavior in loading metal ions

Herein we report the synthesis of a series of poly(4-alkyl-1-vinyl-1,2,4-triazolium) poly(ionic liquid)s either via straightforward free radical polymerization of their corresponding ionic liquid monomers, or via anion metathesis of the polymer precursors bearing halide as counter anion. The ionic liquid monomers were first prepared via N-alkylation reaction of commercially available 1-vinyl-1,2,4-triazole with alkyl iodides, followed by anion metathesis with targeted fluorinated anions. The thermal properties and solubilities of these poly(ionic liquid)s have been systematically investigated. Interestingly, it was found that the poly(4-ethyl-1-vinyl-1,2,4-triazolium) poly(ionic liquid) exhibited an improved loading capacity of transition metal ions in comparison with its imidazolium counterpart.Comment: 18 pages, 9 figure

Ionic-liquid-gating setup for stable measurements and reduced electronic inhomogeneity at low temperatures

The ionic-liquid-gating technique can be applied to the search for novel physical phenomena at low temperatures because of its wide controllability of the charge carrier density. Ionic-liquid gated field-effect transistors are often fragile upon cooling, however, because of the large difference between the thermal expansion coefficients of frozen ionic liquids and solid target materials. In this paper, we provide a practical technique for setting up ionic-liquid-gated field-effect transistors for low-temperature measurements. It allows stable measurements and reduces the electronic inhomogeneity by reducing the shear strain generated in frozen ionic liquid.Comment: 5 pages, 6 figure

First direct evidence of N-heterocyclic carbene in BMIm acetate ionic liquid. An electrochemical and chemical study on the role of temperature

Cyclic voltammetry provides the first direct evidence of N-­heterocyclic carbene (NHC) presence in neat 1-‐butyl-­3-­methylimidazolium acetate ionic liquid (BMImAcO) at 120°C. The NHC existence, proved by its oxidation current in cyclic voltammetry, was confirmed by the formation of a PhCHO-­NHC adduct in pure ionic liquid. The role of the temperature was considered

Electrospun nanosized cellulose fibers using ionic liquids at room temperature

Aiming at replacing the noxious solvents commonly employed, ionic-liquid-based solvents have been recently explored as novel non-volatile and non-flammable media for the electrospinning of polymers. In this work, nanosized and biodegradable cellulose fibers were obtained by electrospinning at room temperature using a pure ionic liquid or a binary mixture of two selected ionic liquids. The electrospinning of 8 wt% cellulose in 1-ethyl-3-methylimidazolium acetate medium (a low viscosity and room temperature ionic liquid capable of efficiently dissolving cellulose) showed to produce electrospun fibers with average diameters within (470 ± 110) nm. With the goal of tailoring the surface tension of the spinning dope, a surface active ionic liquid was further added in a 0.10 : 0.90 mole fraction ratio. Electrospun cellulose fibers from the binary mixture composed of 1-ethyl-3-methylimidazolium acetate and 1-decyl-3-methylimidazolium chloride ionic liquids presented average diameters within (120 ± 55) nm. Scanning electron microscopy, X-ray diffraction analysis, nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric assays were used as core methods to evaluate the structural integrity, morphology and crystallinity of the raw, electrospun, and regenerated samples of cellulose. Moreover, the photoluminescence spectra of both raw and electrospun fibers were acquired, and compared, indicating that the cellulose emitting centers are not affected by the dissolution of cellulose in ionic liquids. Finally, the use of non-volatile solvents in electrospinning coupled to a water coagulation bath allows the recovery of the ionic fluid, and represents a step forward into the search of environmentally friendly alternatives to the conventional approaches

High-performance nn-type organic field-effect transistors with ionic liquid gates

High-performance $n$-type organic field-effect transistors were developed with ionic-liquid gates and N,N$^"$-bis(n-alkyl)-(1,7 and 1,6)-dicyanoperylene-3,4:9,10-bis(dicarboximide)s single-crystals. Transport measurements show that these devices reproducibly operate in ambient atmosphere with negligible gate threshold voltage and mobility values as high as 5.0 cm$^2$/Vs. These mobility values are essentially identical to those measured in the same devices without the ionic liquid, using vacuum or air as the gate dielectric. Our results indicate that the ionic-liquid and $n$-type organic semiconductor interfaces are suitable to realize high-quality $n$-type organic transistors operating at small gate voltage, without sacrificing electron mobility

Lattice Model of an Ionic Liquid at an Electrified Interface

We study ionic liquids interacting with electrified interfaces. The ionic fluid is modeled as a Coulomb lattice gas. We compare the ionic density profiles calculated using a popular modified Poisson-Boltzmann equation with the explicit Monte Carlo simulations. The modified Poisson-Boltzmann theory fails to capture the structural features of the double layer and is also unable to correctly predict the ionic density at the electrified interface. The lattice Monte Carlo simulations qualitatively capture the coarse-grained structure of the double layer in the continuum. We propose a convolution relation that semiquantitatively relates the ionic density profiles of a continuum ionic liquid and its lattice counterpart near an electrified interface