Soluble Fluorinated Cardo Copolyimide as an Effective Additive to Photopolymerizable Compositions Based on Di(meth)acrylates: Application for Highly Thermostable Primary Protective Coating of Silica Optical Fiber.

The development of photocurable compositions is in high demand for the manufacture of functional materials for electronics, optics, medicine, energy, etc. The properties of the final photo-cured material are primarily determined by the initial mixture, which needs to be tuned for each application. In this study we propose to use simple systems based on di(meth)acrylate, polyimide and photoinitiator for the preparation of new photo-curable compositions. It was established that a fluorinated cardo copolyimide (FCPI) based on 2,2-bis-(3,4-dicarboxydiphenyl)hexafluoropropane dianhydride, 9,9-bis-(4-aminophenyl)fluorene and 2,2-bis-(4-aminophenyl)hexafluoropropane (1.00:0.75:0.25 mol) has excellent solubility in di(met)acrylates. This made it possible to prepare solutions of FCPI in such monomers, to study the effect of FCPI on the kinetics of their photopolymerization in situ and the properties of the resulting polymers. According to the obtained data, the solutions of FCPI (23 wt.%) in 1,4-butanediol diacrylate (BDDA) and FCPI (15 wt.%) in tetraethylene glycol diacrylate were tested for the formation of the primary protective coatings of the silica optical fibers. It was found that the new coating of poly(BDDA-FCPI23%) can withstand prolonged annealing at 200 °C (72 h), which is comparable or superior to the known most thermally stable photo-curable coatings. The proposed approach can be applied to obtain other functional materials.

Exploring the effect of fluorinated anions on the CO2/N2 separation of supported ionic liquid membranes.

The CO2 and N2 permeation properties of ionic liquids (ILs) based on the 1-ethyl-3-methylimidazolium cation ([C2mim]+) and different fluorinated anions, namely 2,2,2-trifluoromethylsulfonyl-N-cyanoamide ([TFSAM]-), bis(fluorosulfonyl) imide ([FSI]-), nonafluorobutanesulfonate ([C4F9SO3]-), tris(pentafluoroethyl)trifluorophosphate ([FAP]-), and bis(pentafluoroethylsulfonyl)imide ([BETI]-) anions, were measured using supported ionic liquid membranes (SILMs). The results show that pure ILs containing [TFSAM]- and [FSI]- anions present the highest CO2 permeabilities, 753 and 843 Barrer, as well as the greatest CO2/N2 permselectivities of 43.9 and 46.1, respectively, with CO2/N2 separation performances on top of or above the Robeson 2008 upper bound. The re-design of the [TFSAM]- anion by structural unfolding was investigated through the use of IL mixtures. The gas transport and CO2/N2 separation properties through a pure [C2mim][TFSAM] SILM are compared to those of two different binary IL mixtures containing fluorinated and cyano-functionalized groups in the anions. Although the use of IL mixtures is a promising strategy to tailor gas permeation through SILMs, the pure [C2mim][TFSAM] SILM displays higher CO2 permeability, diffusivity and solubility than the selected IL mixtures. Nevertheless, both the prepared mixtures present CO2 separation performances that are on top of or above the Robeson plot.

Ionic liquids with anions based on fluorosulfonyl derivatives: from asymmetrical substitutions to a consistent force field model.

Herein, seven anions including four imide-based, namely bis[(trifluoromethyl)sulfonyl]imide (TFSI), bis(fluorosulfonyl)imide (FSI), bis[(pentafluoroethyl)sulfonyl]imide (BETI), 2,2,2-trifluoromethylsulfonyl-N-cyanoamide (TFSAM) and 2,2,2-trifluoro-N-(trifluoromethylsulfonyl) acetamide (TSAC), and two sulfonate anions, trifluoromethanesulfonate (triflate, TF) and nonafluorobutanesulfonate (NF), are considered and compared. The volumetric mass density and dynamic viscosity of five ionic liquids containing these anions combined with the commonly used 1-ethyl-3-methylimidazolium cation (C2C1im), [C2C1im][FSI], [C2C1im][BETI], [C2C1im][TFSAM], [C2C1im][TSAC] and [C2C1im][NF] are measured in the temperature range of 293.15 ≤ T/K ≤ 353.15 and at atmospheric pressure. The results show that [C2mim][FSI] and [C2mim][TFSAM] exhibit the lowest densities and viscosities among all the studied ionic liquids. The experimental volumetric data is used to validate a more consistent re-parameterization of the CL&P force field for use in MD simulations of ionic liquids containing the ubiquitous bis[(trifluoromethyl)sulfonyl]imide and trifluoromethanesulfonate anions and to extend the application of the model to other molten salts with similar ions.

A New Volume-Based Approach for Predicting Thermophysical Behavior of Ionic Liquids and Ionic Liquid Crystals.

Volume-based prediction of melting points and other properties of ionic liquids (ILs) relies on empirical relations with volumes of ions in these low-melting organic salts. Here we report an accurate way to ionic volumes by Bader's partitioning of electron densities from X-ray diffraction obtained via a simple database approach. For a series of 1-tetradecyl-3-methylimidazolium salts, the volumes of different anions are found to correlate linearly with melting points; larger anions giving lower-melting ILs. The volume-based concept is transferred to ionic liquid crystals (ILs that adopt liquid crystalline mesophases, ILCs) for predicting the domain of their existence from the knowledge of their constituents. For 1-alkyl-3-methylimidazolium ILCs, linear correlations of ionic volumes with the occurrence of LC mesophase and its stability are revealed, thus paving the way to rational design of ILCs by combining suitably sized ions.

Synthesis and X-ray Characterization of Alkali Metal 2-Acyl-1,1,3,3-tetracyanopropenides.

A novel route for synthesis of 2-acyl-1,1,3,3-tetracyanopropenides (ATCN) salts in high yields and excellent purities starting from readily available methyl ketones, malononitrile, bromine, and alkali metal acetates is reported. The starting aryl(heteroaryl) methyl ketones were oxidized to the corresponding α-ketoaldehydes by new a DMSO-NaBr-H2SO4 oxidation system in yields up to 90% within a short reaction time of 8-10 min. The subsequent stages of ATCN preparation are realized in aqueous media without use of any toxic solvents, in accordance with principle 5 of "green chemistry". Lithium, sodium, potassium, rubidium, and cesium 2-benzoyl-1,1,3,3-tetracyanopropenides were characterized by X-ray diffraction analysis. These salts show a good potential for synthesis of five- and six-membered heterocycles and may serve as potentially useful ligands in coordination and supramolecular chemistry.

Ionic Polyureas-A Novel Subclass of Poly(Ionic Liquid)s for CO2 Capture.

The growing concern for climate change and global warming has given rise to investigations in various research fields, including one particular area dedicated to the creation of solid sorbents for efficient CO2 capture. In this work, a new family of poly(ionic liquid)s (PILs) comprising cationic polyureas (PURs) with tetrafluoroborate (BF4) anions has been synthesized. Condensation of various diisocyanates with novel ionic diamines and subsequent ion metathesis reaction resulted in high molar mass ionic PURs (Mw = 12 ÷ 173 × 103 g/mol) with high thermal stability (up to 260 °C), glass transition temperatures in the range of 153-286 °C and remarkable CO2 capture (10.5-24.8 mg/g at 0 °C and 1 bar). The CO2 sorption was found to be dependent on the nature of the cation and structure of the diisocyanate. The highest sorption was demonstrated by tetrafluoroborate PUR based on 4,4'-methylene-bis(cyclohexyl isocyanate) diisocyanate and aromatic diamine bearing quinuclidinium cation (24.8 mg/g at 0 °C and 1 bar). It is hoped that the present study will inspire novel design strategies for improving the sorption properties of PILs and the creation of novel effective CO2 sorbents.

Single-Ion Block Copoly(ionic liquid)s as Electrolytes for All-Solid State Lithium Batteries.

Polymer electrolytes have been proposed as replacement for conventional liquid electrolytes in lithium-ion batteries (LIBs) due to their intrinsic enhanced safety. Nevertheless, the power delivery of these materials is limited by the concentration gradient of the lithium salt. Single-ion conducting polyelectrolytes represent the ideal solution since their nature prevents polarization phenomena. Herein, the preparation of a new family of single-ion conducting block copolymer polyelectrolytes via reversible addition-fragmentation chain transfer polymerization technique is reported. These copolymers comprise poly(lithium 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethylsulfonyl)imide) and poly(ethylene glycol) methyl ether methacrylate blocks. The obtained polyelectrolytes show low Tg values in the range of -61 to 0.6 °C, comparatively high ionic conductivity (up to 2.3 × 10(-6) and 1.2 × 10(-5) S cm(-1) at 25 and 55 °C, respectively), wide electrochemical stability (up to 4.5 V versus Li(+)/Li), and a lithium-ion transference number close to unity (0.83). Owing to the combination of all mentioned properties, the prepared polymer materials were used as solid polyelectrolytes and as binders in the elaboration of lithium-metal battery prototypes with high charge/discharge efficiency and excellent specific capacity (up to 130 mAh g(-1)) at C/15 rate.

A first truly all-solid state organic electrochromic device based on polymeric ionic liquids.

Using polymeric ionic liquids and PEDOT as ion conducting separators and electrodes, respectively, an all-polymer-based organic electrochromic device (ECD) has been constructed. The advantages of such an ECD are: fast switching time (3 s), high coloration efficiency (390 cm(2) C(-1) at 620 nm), optical contrast up to ΔT = 22% and the possibility of working under vacuum.

Ammonium 3-cyano-4-(dicyanomethylene)-5-oxo-4,5-dihydro-1H-pyrrol-2-olate monohydrate.

Each anion of the title salt, NH4+.C8HN4O2-.H2O, is linked by two N-H...O hydrogen bonds to another anion, thus forming an essentially planar centrosymmetric dimer. The dimers are considered to be molecular building blocks of an anionic wall. The building blocks form infinite ribbons via -C-N...N-C- dipole-dipole and pi-pi interactions. Adjacent ribbons are stacked by means of pi-pi interactions, thus forming an anionic wall. Neighbouring walls are connected by (NH4+...H2O)n chains running along the b axis.