Room Temperature Ionic Liquids from 20 Natural Amino Acids

We first succeeded in synthesizing ionic liquids from 20 natural amino acids. Amino acid ionic liquids dissolved native amino acids, despite water-free conditions. Furthermore, these ionic liquids are soluble in various organic solvents, such as chloroform. Effects of acidity, hydrogen bonding ability, and steric factors on the properties of these ionic liquids were analyzed as the function of side groups

Superior Solubility of Polysaccharides in Low Viscosity, Polar, and Halogen-Free 1,3-Dialkylimidazolium Formates

We successfully prepared low viscosity, polar, and halogen-free ionic liquids as potential solvents for a wide range of polysaccharides. A series of 1,3-dialkylimidazolium formates were produced as liquids having strong hydrogen bond acceptability. These formates had significantly lower viscosity than previously reported polar ionic liquids, in particular 1-allyl-3-methylimidazolium formate (viscosity 66cP at 25 °C) and 1-allyl-3-ethylimidazolium formate (67cP at 25 °C). Because of their strong hydrogen bond ability, various polysaccharides including amylose and (scarcely soluble) cellulose were dissolved in high concentrations under mild condition

Selective Ion Transport in Organoboron Polymer Electrolytes Bearing a Mesitylboron Unit

Selective Ion Transport in Organoboron Polymer Electrolytes Bearing a Mesitylboron Uni

3D Continuous Water Nanosheet as a Gyroid Minimal Surface Formed by Bicontinuous Cubic Liquid-Crystalline Zwitterions

Co-organization of amphiphilic zwitterions and bis­(trifluoromethanesulfonyl)­imide led to the formation of bicontinuous cubic liquid-crystalline structures having 3D continuous hydrophilic gyroid minimal surface. The gyroid surface, incorporating a small amount of water, provided extremely thin but macroscopically continuous water nanosheet with a thickness of approximately 5 Å. The water nanosheet functioned as alignment free proton conduction pathway

Maintenance-Free Cellulose Solvents Based on Onium Hydroxides

Here, we report maintenance-free cellulose solvents that dissolve much cellulose within a few minutes under mild conditions even in the presence of water. We have examined a series of aqueous solutions of tetraalky-phosphonium and tetraalkyl-ammonium hydroxides to clarify the effect of cation species on cellulose dissolving. Aqueous solutions of the many hydroxides examined here were found to dissolve cellulose at room temperature, and electrostatic interaction and/or steric hindrance of component ions are suggested to affect the cellulose-dissolving ability. In spite of increasing water content after dissolution of wet cellulose, the water content automatically reduced to less than 60% just by keeping the filtrated solution in the air. The solvation state of cellulose in aqueous onium hydroxide solutions is discussed with ¹³C NMR chemical shift of cellobiose signals in these solutions. They dissolve cellulose only when the ¹³C NMR signal of the carbon atom at the 12 position of cellobiose is 64.8 ppm or larger in the hydroxide aqueous solution

One-Dimensional Ion Transport in Self-Organized Columnar Ionic Liquids

New fan-shaped ionic liquids forming columnar liquid crystalline phases have been prepared to obtain one-dimensional ion-transporting materials. The ionic liquids consist of two incompatible parts:  an imidazolium-based ionic part as an ion-conducting part and tris(alkyloxy)phenyl parts as insulating parts. Two compounds having octyl and dodecyl chains have been synthesized. Self-assembly of these materials leads to the formation of thermotropic hexagonal columnar liquid crystalline states at room temperature. Anisotropic one-dimensional ionic conductivities have been successfully measured by the cells having comb-shaped gold electrodes. The self-organized columns have been aligned macroscopically in two directions by shearing perpendicular and parallel to the electrodes. The ionic conductivities parallel to the column axis are higher than those perpendicular to the axis. The incorporation of lithium salts in these columnar materials leads to the enhancement of the ionic conductivities and their anisotropy. These materials would be useful for anisotropic transportation of ions at the nanometer level

Isolation and Quantification of Polyamide Cyclic Oligomers in Kitchen Utensils and Their Migration into Various Food Simulants

<div><p>Small amounts of cyclic monomers and oligomers are present in polyamide (PA)-based kitchen utensils. In this study, we isolated eight PA-based cyclic monomers and oligomers from kitchen utensils made from PA6 (a polymer of ε-caprolactam) and PA66 (a polymer of 1,6-diaminohexane and adipic acid). Their structures were identified using high-resolution mass spectrometry and ¹H- and ¹³C-nuclear magnetic resonance spectroscopy, and their residual levels in PA-based kitchen utensils and degree of migration into food simulants were quantified by high-performance liquid chromatography/mass spectrometry using purchased PA6 monomer and isolated PA66 monomers, and isolated PA6 and PA66 oligomers as calibration standards. Their total residual levels among 23 PA-based kitchen utensils made from PA6, PA66, and copolymers of PA6 and PA66 (PA6/66) ranged from 7.8 to 20 mg/g. Using water, 20% ethanol, and olive oil as food simulants, the total migration levels of the PA monomers and oligomers ranged from 0.66 to 100 μg/cm² under most examined conditions. However, the total migration levels of the PA66 monomer and oligomers from PA66 and PA6/66 kitchen utensils into 20% ethanol at 95°C were very high (1,700 and 2,200 μg/cm², respectively) due to swelling by high-temperature ethanol.</p></div

Migration levels of PA cyclic monomers and oligomers from the sesame grinder (PA6) and cake server (PA6/66) into three simulants at 60°C.

<p>Migration levels of PA cyclic monomers and oligomers from the sesame grinder (PA6) and cake server (PA6/66) into three simulants at 60°C.</p

Migration levels of PA cyclic monomers and oligomers from ladles 1 (PA6), 8 (PA66), and 5 (PA6/66) into three simulants at 95°C.

Migration levels of PA cyclic monomers and oligomers from ladles 1 (PA6), 8 (PA66), and 5 (PA6/66) into three simulants at 95°C.</p

Nanostructured Liquid Crystals Combining Ionic and Electronic Functions

New molecular materials combining ionic and electronic functions have been prepared by using liquid crystals consisting of terthiophene-based mesogens and terminal imidazolium groups. These liquid crystals show thermotropic smectic A phases. Nanosegregation of the π-conjugated mesogens and the ionic imidazolium moieties leads to the formation of layered liquid-crystalline (LC) structures consisting of 2D alternating pathways for electronic charges and ionic species. These nanostructured materials act as efficient electrochromic redox systems that exhibit coupled electrochemical reduction and oxidation in the ordered bulk states. For example, compound 1 having the terthienylphenylcyanoethylene mesogen and the imidazolium triflate moiety forms the smectic LC nanostructure. Distinct reversible electrochromic responses are observed for compound 1 without additional electrolyte solution on the application of double-potential steps between 0 and 2.5 V in the smectic A phase at 160 °C. In contrast, compound 2 having a tetrafluorophenylterthiophene moiety and compound 3 having a phenylterthiophene moiety exhibit irreversible cathodic reduction and reversible anodic oxidation in the smectic A phases. The use of poly(3,4-ethylenedioxythiophene)−poly(4-styrene sulfonate) (PEDOT−PSS) as an electron-accepting layer on the cathode leads to the distinct electrochromic responses for 2 and 3. These results show that new self-organized molecular redox systems can be built by nanosegregated π-conjugated liquid crystals containing imidazolium moieties with and without electroactive thin layers on the electrodes