Electrogenerated BF3 From Tetrafluoroborate-Based Ionic Liquids: Theoretical And Experimental Studies Towards Selective Styrene Oxide Isomerization

The anodic oxidation of tetrafluoroborate anion yields the Lewis acid BF3. If this reaction is carried out in an imidazolium ionic liquid, a quite stable system containing BF3 is obtained, whose reactivity is similar to the one of BF3·Et2O, but less harmful. The two reagents’ stabilities were compared by computational analysis, strongly suggesting a higher stability for BF3/BMIm-BF4 system. The effect of substituents on the imidazolium ring and of the electrochemical configuration on BF3 reactivity were studied in a model reaction, styrene oxide isomerization. The experimental conditions were defined for the selective formation of phenylacetaldehyde or of 2-benzyl-4-phenyl-1,3-dioxolane. Moreover, the formation of N-heterocyclic carbene-BF3 adduct was confirmed when carrying out the electrolysis in an undivided cell. Electrogenerated BF3/BMIm-BF4 system demonstrated to be a valid alternative to commercial BF3·Et2O.

Differential Influence of Imidazolium Ionic Liquid on Cellulase Kinetics in Saccharification of Cellulose and Lignocellulosic Biomass Substrate

The effect of [Emim][OAc] on Celluclast 1.5 L, Accellerase 1500, and IL-tolerant (MSL2) cellulase during the saccharification of carboxymethylcellulose (CMC), Avicel (AV), rice straw (RS) was studied in one pot process (pretreatment and saccharification). The inhibition caused by [Emim][OAc] (0.5–2.0 M) with substrate loading (20–50 mg/mL) were also evaluated. In most cases, the inhibition mode of saccharification for CMC and AV was identified to be uncompetitive inhibition when the concentration of [Emim][OAc] was higher than 0.5 M. Under the influence of 0.5 M of [Emim][OAc], the Critical Concentration of Substrate (CCS) values of the Celluclast 1.5 L and Accellerase 1500 on CMC hydrolysis were determined to be at 26.59 and 33.65 mg/mL, respectively. Also, increasing in [Emim][OAc] concentration could increase in CCS values, suggesting the positive effect of [Emim][OAc] on the improvement of enzymatic saccharification. This study provides insight into the process optimization for integration of [Emim][OAc] in one pot process of biorefinery.

Surface Analyses of PVDF/NMP/[EMIM][TFSI] Solid Polymer Electrolyte

Thermal treatment conditions of solid polymer polymer electrolyte (SPE) were studied with respect to their impact on the surface morphology, phase composition and chemical composition of an imidazolium ionic-liquid-based SPE, namely PVDF/NMP/[EMIM][TFSI] electrolyte. These investigations were done using scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry as well as X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy. A thoroughly mixed blend of polymer matrix, ionic liquid and solvent was deposited on a ceramic substrate and was kept at a certain temperature for a specific time in order to achieve varying crystallinity. The morphology of all the electrolytes consists of spherulites whose average diameter increases with solvent evaporation rate. Raman mapping shows that these spherulites have a semicrystalline structure and the area between them is an amorphous region. Analysis of FTIR spectra as well as Raman spectroscopy showed that the β-phase becomes dominant over other phases, while DSC technique indicated decrease of crystallinity as the solvent evaporation rate increases. XPS and ToF-SIMS indicated that the chemical composition of the surface of the SPE samples with the highest solvent evaporation rate approaches the composition of the ionic liquid.

Ionogels Based on a Single Ionic Liquid for Electronic Nose Application

Ionogel are versatile materials, as they present the electrical properties of ionic liquids and also dimensional stability, since they are trapped in a solid matrix, allowing application in electronic devices such as gas sensors and electronic noses. In this work, ionogels were designed to act as a sensitive layer for the detection of volatiles in a custom-made electronic nose. Ionogels composed of gelatin and a single imidazolium ionic liquid were doped with bare and functionalized iron oxide nanoparticles, producing ionogels with adjustable target selectivity. After exposing an array of four ionogels to 12 distinct volatile organic compounds, the collected signals were analyzed by principal component analysis (PCA) and by several supervised classification methods, in order to assess the ability of the electronic nose to distinguish different volatiles, which showed accuracy above 98%.