Ionic Liquids and Deep Eutectics as a Transformative Platform for the Synthesis of Nanomaterials

Ionic liquids (ILs) are becoming a revolutionary synthesis medium for inorganic nanomaterials, permitting more efficient, safer and environmentally benign preparation of high quality products. A smart combination of ILs and...

Functionalized Organosolv Lignins Suitable for Modifications of Hard Surfaces

Two different organosolv lignins (OSLs), that is, wheat straw and corn stover OSLs, were chemically and enzymatically functionalized. Functional groups were attached via the formation of stable ether bonds exploiting the reactivity of free phenolic OH groups along the lignin backbone. The functional groups introduced a range from compact charged and chargeable building blocks for the generation of surface-active lignins to oligomeric and polymeric species used in lignin block-copolymer productions. Combination of selected functions led to novel charged or chargeable polymeric lignin-based materials. Products could be realized with different degrees of technical loadings in terms of introduced functional groups.

Size and shape-controlled synthesis of Ru nanocrystals

Mastery over the size/shape of nanocrystals (NCs) enables control of their properties and enhancement of their usefulness for a given application. Within the past decades, the development of wet-chemistry methods leads to the blossom of research in noble metal nanomaterials with tunable sizes and shapes. We herein would prefer to devote this chapter to introduce the solution-based methods for size and shape-controlled synthesis of ruthenium (Ru) NCs, which can be summarized into five categories: (i) Synthesis of spherical Ru NCs; (ii) synthesis of one-dimensional (1D) Ru NCs, e.g. wires and rods; (iii) synthesis of two-dimensional (2D) Ru NCs, e.g. nanoplates; (iv) synthesis of Ru NCs with hollow interiors and (v) synthesis of Ru NCs with other morphologies, e.g. chains, dendrites and branches. We aim at highlighting the synthetic approaches and growth mechanisms of these types of Ru NCs. We also introduce the detailed characterization tools for analysis of Ru NCs with different sizes/shapes. With respect to the creation of great opportunities and tremendous challenges due to the accumulation in noble metal nanomaterials, we briefly make some perspectives for the future development of Ru NCs so as to provide the readers a systematic and coherent picture of this promising field. We hope this reviewing effort can provide for technical bases for effectively designing and producing Ru NCs with enhanced physical/chemical properties.

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Monitoring the solvation process and stability of Eu2+ in an ionic liquid by in situ luminescence analysis

Ionic liquids (ILs) offer the remarkable possibility of the direct synthesis of Eu2+-doped nanophosphors in solution, under atmospheric conditions, without the necessity of a high-temperature post-synthetic reduction from its trivalent oxidation state. This work uses for the first time in situ luminescence measurements for monitoring the solvation process of Eu2+ from the solid salt to the IL and its stability against oxidation under atmospheric conditions. Upon the addition of EuBr2 to 1-butyl-3-methyl-imidazolium tetrafluoroborate, the formation of the solvation shell is detected by the shift of the emission band at approximately 24 100 cm−1 assigned to the 5d→4f electronic transitions of Eu2+ within EuBr2 to approximately 22 000 cm−1, assigned to Eu2+ within BminBF4, tracking the time-dependent influence of the Eu2+ coordination environment on the crystal field splitting of its d orbitals. Even though the solubility of EuBr2 was demonstrated to be improved by reducing the concentration and increasing the temperature to 60°C, the performance of reactions at room temperature is recommended for future synthesis of Eu2+ materials in ILs due to the slight oxidation to Eu3+ observed upon heating.

A novel approach to prepare optically active ion doped luminescent materials via electron beam evaporation into ionic liquids

A novel approach to prepare luminescent materials via electron-beam evaporation into ionic liquids is presented which even allows doping of host lattices with ions that have a strong size mismatch. To prove this, MgF2 nanoparticles doped with Eu(3+) were fabricated. The obtained nanoparticles featured an unusually high luminescence lifetime and the obtained material showed a high potential for application.

Triazolium based ionic liquid crystals: effect of asymmetric substitution

A new series of asymmetrical 1-dodecyl-3-alkyl-triazolium bromides has been synthesized to investigate the effect of asymmetric substitution on their phase behavior.

Novel luminescent soft materials of terpyridine-containing ionic liquids and europium(III)

Herein, we describe novel luminescent soft materials via reaction of Eu(3+)-coordinated carboxyl functionalized ionic liquids with terpyridine-functionalized imidazolium salts that are built from an imidazolium ring substituted on one side with a terpyridine derivative and, on the opposite side, a paraffin chain of various lengths. The obtained materials are either pastelike substances or viscous fluids, depending on the anions of the carboxyl functionalized ionic liquids. The soft luminescent materials were investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetry (TG), and luminescence spectroscopy. The soft materials show bright red emission irradiated with UV light, because of the energy transfer from terpyridine-functionalized imidazolium salts to the Eu(3+) ions. The absolute quantum yields of the materials were determined and the energy transfer efficiency was estimated according to the reported method.

Influence of the ionic liquid/gas surface on ionic liquid chemistry

Applications such as gas storage, gas separation, NP synthesis and supported ionic liquid phase catalysis depend upon the interaction of different species with the ionic liquid/gas surface. Consequently, these applications cannot proceed to the full extent of their potential without a profound understanding of the surface structure and properties. As a whole, this perspective contains more questions than answers, which demonstrates the current state of the field. Throughout this perspective, crucial questions are posed and a roadmap is proposed to answer these questions. A critical analysis is made of the field of ionic liquid/gas surface structure and properties, and a number of design rules are mined. The effects of ionic additives on the ionic liquid/gas surface structure are presented. A possible driving force for surface formation is discussed that has, to the best of my knowledge, not been postulated in the literature to date. This driving force suggests that for systems composed solely of ions, the rules for surface formation of dilute electrolytes do not apply. The interaction of neutral additives with the ionic liquid/gas surface is discussed. Particular attention is focussed upon H(2)O and CO(2), vital additives for many applications of ionic liquids. Correlations between ionic liquid/gas surface structure and properties, ionic liquid surfaces plus additives, and ionic liquid applications are given.

Sonochemical synthesis of 0D, 1D, and 2D zinc oxide nanostructures in ionic liquids and their photocatalytic activity

Ultrasound synthesis of zinc oxide from zinc acetate and sodium hydroxide in ionic liquids (ILs) is a fast, facile, and effective, yet highly morphology- and size-selective route to zinc oxide nanostructures of various dimensionalities. No additional organic solvents, water, surfactants, or templating agents are required. Depending on the synthetic conditions, the selective manufacturing of 0D, 1D, and 2D ZnO nanostructures is possible: Whereas the formation of rodlike structures is typically favored, ZnO nanoparticles can be obtained either under strongly basic conditions or by use of ILs with a long alkyl chain, such as 1-n-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C(n)mim][Tf(2)N]; n>8). A short ultrasound irradiation time favors the formation of ZnO nanosheets. Prolonged irradiation leads to the conversion of the ZnO nanosheets into nanorods. In contrast, ionothermal synthesis (conventional heating) does not allow for morphology tuning by variation of the IL or other synthesis conditions, as the longer reaction times required lead always to the formation of well-developed hexagonal nanocrystals with prismatic tips. The ZnO nanostructures synthesized by using ultrasound were efficient photocatalysts in the photodegradation of methyl orange. The photoactivity was observed to be as high as 95 % for ZnO nanoparticles obtained in [C(10)mim][Tf(2)N].