Mitsuo Okahara

Preparation and surface active properties of amphipathic compounds with two sulfate groups and two lipophilic alkyl chains

These compounds with various connecting groups between the two lipophilic groups were prepared by the reaction of glycol diglycidyl ethers with long-chain alcohols, followed by sulfation with chlorosulfonic acid or with a mixture of chlorosulfonic acid and acetic acid. The Krafft point of all these new amphipathic compounds was below 0°C, and they had good water solubility. These compounds were superior in surface active properties to general anionic surfactants with one lipophilic chain and one hydrophilic group, such as sodium dodecylsulfate. The effect of the structure of the connecting group on CMC, γCMC, foaming properties and wetting ability was investigated. They also showed excellent lime-soap dispersing ability.

Preparation and properties of glycerol-based double- or triple-chain surfactants with two hydrophilic ionic groups

A novel series of glycerol-based double- or triple-chain surfactants with two sulfonate, two sulfate or two carboxylate groups was conveniently prepared by reactions of 1-O-alkylglycerol diglycidyl ethers with long-chain fatty alcohols, and followed by reactions with propanesultone, chlorosulfonic acid or bromoacetic acid, respectively. The sulfate and carboxylate types of compounds have higher water solubilities than the corresponding sulfonate type of compound bearing the same lipophilic group. The triple-chain surfactants show excellent surface-active properties, such as micelle forming and ability to lower surface tension, compared not only with the corresponding single-chain anionic surfactants, but also with the corresponding double-chain surfactants. The effect of the difference in head groups of these compounds on surface-active properties is described. Foaming properties, wetting ability and lime-soap dispersing requirement are also discussed.

Sodium-selective PVC membrane electrodes based on bis(12-crowns-4)s

Abstract Sodium-selective PVC membrane electrodes based on newly synthesized bis(crown ether)s containing 12-crown-4 moities were prepared using o -nitrophenyloctylether as a plasticizer of the PVC membrane. The selectively coefficients for alkali metal ions k NaM , were sufficiently small, and markedly depend on the chain lenght and structure of bis(12-crown-4)s. These electrodes show excellent properties, and the electrode response was stable in a wide pH range.

Preparation and surface- active properties of new amphipathic compounds with two phosphate groups and two long- chain alkyl groups

New compounds bearing two dihydrogen phosphate groups and two long- chain alkyl groups (octyl or decyl) were prepared in good yields by the reaction of 1,ω-bis(alkyloxymethyl)- oligo (ethylene glycol)s with polyphosphoric acid.Amphipathic di- or tetrasodium phosphates were obtained by neutralization of the free acids with sodium hydroxide, and their surface- active properties in water were measured. Almost all these di- or tetrasodium phosphates showed good water solubility. Their abilities to form micelles and to lower surface tension were fairly good as compared with general monoalkyl phosphates consisting of one longer alkyl chain and one hydrophilic group. The foaming property of aqueous solutions of the tetrasodium salts was different from that of the disodium salts. The former showed very low foaming ability.

Preparation, surface-active properties and acid decomposition profiles of a new “soap” bearing a 1,3-dioxolane ring

New soap-type surfactants bearing a 1,3-dioxolane ring were prepared in good yields by the acid-catalyzed condensation of 1-O-alkylglycerols (alkyl: decyl, dodecyl, tetradecyl, heptadecyl, octadecyl, orcis-9-octadecenyl) with oxocarboxylic acid esters, followed by alkaline hydrolysis without any expensive reagent and special equipment. These surfactants were soluble in alkaline water at room temperature. Their critical micelle concentrations were much smaller than that of sodium dodecanoate. An alkaline solution of the octadecyl homologue was nonfoaming, but the other homologues, including thecis-9-octadecenyl derivative, showed high foaming ability in alkaline solutions. The structural effect of these compounds on the area per molecule at the surface is also discussed. Because these surfactants contain a 1,3-dioxolane ring, they can be utilized as a new acid-decomposable type of cleavable surfactant. At pH 1, they decompose almost completely into nonsurface-active species after 80 min.

Extractive Separation of Lithium Isotopes by Crown Ethers

Abstract Separative abilities of crown ethers to lithium isotopes were investigated for the number of oxygen atoms composing crown rings and for the substituted groups to 15-crown-5. The separation factors at 0°C were 1.057 for 12-crown-4, 1.042 for benzo-15-crown-5, 1.041 for lauryloxymethyl-15-crown-5, 1.043 for tolyloxymethyl-15-crown-5, and 1.024 for dicyclohexano-18-crown-6. The enthalpy change of the isotopic equilibrium in the absolute value was the greatest for 12-crown-4; ΔH° = −0.78 kJ/mol. In the substituted 15-crown-5s the separation factor was greatest for tolyloxymethyl-15-crown-5, and ΔH° values decreased in the order: benzo- > tolyloxymethyl- > lauryloxymethyl-15-crown-5. For enthalpy changes, benzo-15-crown-5 has the possibility of giving a larger separation factor than the present one, α = 1.042, by choosing more suitable conditions. In spite of its large distribution coefficient, dicyclohexano-18-crown-6 is not superior for isotopic separation of lithium in regard to the small enthalpy ...

Preparation and properties of double- or triple- chain surfactants with two sulfonate groups derived fromN- Acyldiethanolamines

Bis(sulfonate) types of amphipathic compounds with three long- chain alkyl groups were prepared by the reaction ofN- (long- chain acyl)diethanolamine diglycidyl ethers with long- chain fatty alcohols, followed by the reaction with propanesultone. The diglycidyl ethers were easily obtained from the correspondingN- acyldiethanolamines and epichlorohydrin in the presence of a phasetransfer catalyst. The same types of compounds with two longchain alkyl groups were also prepared from Nacetyldiethanolamine according to similar procedures. All these new double- or triple- chain surfactants were soluble in water and showed much better micelle forming and ability to lower surface tension than general types of single- chain surfactants with one sulfonate group. The critical micelle concentration (CMC) and γCMC values of the triple- chain compounds were still much smaller than those of the corresponding double- chain compounds with two common alkyl groups. The efficiency of adsorption at the water/air interface (pC20) of these surfactants was very high. Their foaming properties, wetting ability toward a felt chip, and lime- soap dispersing ability were measured.

Complexing ability of N-oligoethylene glycol monoaza crown ethers with sodium and potassium cations

Abstract N-Oligoethylene glycol monoaza crown ethers were prepared, and the notable effect of oxyethylene oxygen atoms of the side chain on complexing ability with sodium and potassium cations was confirmed.

Active transport of ions using synthetic ionophores derived from macrocyclic polyethers and the related compounds

In the biological field, much attention has been directed toward the transport phenomena through membrane. Although the function of some natural ionophores has been known, the investigation of active and selective transport of ions using the artificial ionophores in the simple model systems may be important to simulate the biological systems and clarify the transport behaviour of natural membranes.

Double-chain surfactant as a new and useful micelle-forming reagent for micellar electrokinetic chromatography

Abstract Disodium 5,12-bis(dodecyloxymethyl)-4,7,10,13-tetraoxa-1,16-hexadecanedisulphonate, a surfactant with two ionic groups and two lipophilic chains, was f