The design and fabrication of chiral nanostructures is a promising approach to realize enantiomeric recognition and separation. In our work, gold nanorod@chiral mesoporous silica core–shell nanoparticles (GNR@CMS NPs) have been successfully synthesized. This novel material exhibits strong and tunable circular dichroism signals in the visible and near-infrared regions due to the optical coupling between the CMS shells and the GNR cores. When chiral cysteine molecules are loaded in the porous shells, the corresponding surface enhanced Raman scattering spectroscopy demonstrates a distinct chiral recognition effect, which can be used to semiquantitatively measure the composition of chiral enantiomers. A detailed sensing mechanism has been disclosed by density functional theory calculations.

Gold nanorod@chiral mesoporous silica core-shell nanoparticles with unique optical properties.

Amino acid-based surfactants – do they deserve more attention?

Helical conducting polymer nano-structures have attracted increasing attention because of their superior optical and electrical activities, lightweight, and flexibility as well as controllable morphologies at several levels of a hierarchy. Nevertheless, hardly any research has focused on helical conducting polymer nano-structure based electromagnetic protecting materials. Herein, we synthesized single-handed helical polypyrrole (PPy) nano-structures by a chiral inducing route and demonstrated their amazing electromagnetic protecting abilities. A gradually constructed conducting network and helical chirality may be the main reasons for the tunable and impressive electromagnetic protecting performance of the as-prepared helical PPy nano-structures. This research opens up an opportunity for the application of single-handed helical conducting polymer nano-structures as a lightweight and tunable high-performance electromagnetic protecting material, especially in the fields of special aircraft, aerospace and fast-growing next-generation flexible electronics.

Chiral induced synthesis of helical polypyrrole (PPy) nano-structures: a lightweight and high-performance material against electromagnetic pollution

Non-conventional surfactants from amino acids and glycolipids: Structure, preparation and properties

Properties and applications of amino acid based surfactants

Long chain N-acylglutamic acid was prepared in a high yield by a reaction of glutamic acid with fatty acid chloride in a mixed solvent of water and a water miscible organic solvent such as acetone, methyl ethyl ketone, dioxane, tetrahydrofuran,t-butyl alcohol or cyclohexanone. In this reaction the composition of the mixed solvent influenced the yield of N-acylated glutamic acid and the best yield was obtained when the reaction was carried out in the mixed solvent comprising 30–60% v/v of the organic solvent. Long chain N-acylaspartic acid was also obtained in a high yield by the same method. As the other method to obtain N-lauroyl-D L-glutamic acid, it was examined that N-acyl-α-aminoglutarodinitrile which was obtained by a reaction of α-aminoglutarodinitrile with fatty acid chloride was hydrolyzed with an aqueous alkaline solution. The salts of long chain N-acylglutamic acid are known as the surface active agents that react mildly on the human skin.

Surface active N-acylglutamate: I. Preparation of long chain N-acylglutamic acid

The physicochemical properties of long chain N-acylglutamic acids (AGA) and their sodium salts (AGSn) are described. The solubility, Krafft point, pH value, critical micelle concentration, surface tension and foaming power were measured. The properties of the optically active AGA or AGSn differed from those of the corresponding racemates, especially in solubility. The monosodium salts generally had high Krafft points, but monosodium N-oleoylglutamate had a low Krafft point. The monosodium salts hydrolyzed in the diluted aqueous solution to liberate the AGA. The aqueous solutions of the monosodium salts had low surface tensions and good foaming properties. The disodium salts were highly soluble in water, while surface tensions and foaming properties were inferior to those of the corresponding monosodium salts.

Surface active N-acylglutamate: II. Physicochemical properties of long chain N-acylglutamic acids and their sodium salts

The physicochemical properties of triethanolamine long chain N-acylglutamates are described. The monotriethanolamine salts were less soluble in water and superior in surface activity, compared with the corresponding ditriethanolamine salts. The monotriethanolamine salt showed weak acidity in an aqueous solution. There were some differences between optically active and racemic N-acylglutamates, especially in the values of critical micelle concentration.

Surface-active N-acylglutamate: IV. Physicochemical properties of triethanolamine long chain N-acylglutamates

The physicochemical properties of sodium long chain N-acylglutamate (AGSn) are described. The wetting power, emulsifying power, dispersing power and calcium ion stability were measured. Monosodium N-lauroyl-l-glutamate (l-LGS) had good wetting and emulsifying properties, but disodium N-acylglutamate (AGS2) was inferior tol-LGS in those properties. In the dispersing power using carbon black as powder,l-LGS was inferior but AGS2, having a palmitoyl or stearoyl radical, was excellent. The AGSn with a few exceptions had good calcium ion stabilities.

Surface active N-acylglutamate: III. Physicochemical properties of sodium long chain N-acylglutamates

Epoxides and acrylonitrile react with spiroacetal diamines of the formula TO FORM A VISCOUS LIQUID WHICH IS A GOOD HARDENER FOR EPOXY RESIN INTERMEDIATES, IN THE FORMULA R being hydrogen, methyl, or ethyl, and R' being alkyl having one to six carbon atoms. Epoxy resins cured by means of the hardener are flexible, colorless and transparent.

Ippei Yoshimura

Papers

Surface active N-acylglutamate: I. Preparation of long chain N-acylglutamic acid

Surface active N-acylglutamate: II. Physicochemical properties of long chain N-acylglutamic acids and their sodium salts

Surface-active N-acylglutamate: IV. Physicochemical properties of triethanolamine long chain N-acylglutamates

Surface active N-acylglutamate: III. Physicochemical properties of sodium long chain N-acylglutamates

Curing agent for epoxy resins