Ajay K. Jain

Effect of alcohols on counteriono association in aqueous solutions of sodium dodecyl sulfate

The study of counterion association is of importance as it throws light on the parameters affecting micellar behavior. A number of methods have been used to determine the extent of counterion association and they often tend to give widely different values. Ion-selective membrane electrodes of adequate mechanical and chemical stability which are not poisoned by surfactants are expected to give a direct measure of counterion activity. A number of membrane electrodes have been investigated to determine counterion association. In this study a report is given on the use of a new membrane electrode system of adequate mechanical and chemical stability which is not poisoned by surfactants and alcohols. The effect of alcohols on counterion association of sodium dodecyl sulfate is investigated systematically. 13 references.

Electrometric determination of critical micelle concentration of soap solutions

Abstract The variation of detergent anion activity with, concentration in solutions of potassium laurate, myristate, palmitate and stearate has been studied using the cobalt, cobalt soap electrode. The detergent anion activity increases at first, reaches a maximum at the c.m.c. and thereafter remains almost constant. The constant value of the activity above the c.m.c. shows that the excess of soap added goes into solution in the form of micelles. The c.m.c. values of potassium laurate, myristate, palmitate and stearate are 2.512 × 10−2 M, 6.918 × 10−3M ,3.162 × 10−3 M and 8.71 × 10−4M, respectively. In the presence of urea, the rnicellization of potassium laurate and myristate takes place at higher concentrations.

Solubility of cobalt laurate in water and non-aqueous solvents

Die bisher unbekannte Löslichkeit von Kobaltlaurat wurde mit Hilfe der Tracer-Technik unter Verwendung von58Co bestimmt. Die Löslichkeit in Wasser und organischen Lösungsmitteln (mit Ausnahme von Methanol) ist sehr gering. Die relativ grosse Löslichkeit in Methanol wird auf Bildung von Co2+-Methanol-Komplexen zurückgeführt.

Solutions of soaps in organic solvents

The solubilities of silver and chromium soaps in nonaqueous solvents have been determined by a radiotracer technique. The metal soaps are sparingly soluble in nonaqueous solvents but more soluble in alcohols. The solubility data at different temperatures in benzene, toluene, and m-xylene has been used to determine the critical micelle concentration (c.m.c) of these soaps. Small amounts of methanol enhance the solubility of the metal soaps in benzene and the viscosity of soap solutions in methanol–benzene (15% methanol) showed the existence of micelles at high soap concentrations. The solubility of silver laurate in aqueous solutions of dioctyl sodium sulphosuccinate and Nonidet-P40 has been determined and the data was used to calculate the c.m.c. of aqueous surfactants.

Solubility of cadmium laurate using radioactive 115mCadmium as a tracer

Abstract The solubility of cadmium laurate in water, many nonaqueous solvents, and aqueous solutions of Manoxol OT has been determined by using 115mCd as a tracer and in methanol-benzene mixtures by an evaporation method. The cadmium soap has been found to be spare both in water and in many nonaqueous solvents. However, its solubility in alcohols is relatively much higher, owing to solute-solvent interaction. The c.m.c. values of cadmium laurate in benzene, toluene, and m-xylene have been calculated from the solubility data at different temperatures and found to be 3.8 × 10−5 M, 9.0 × 10−5 M, and 9.8 × 10−5 M, respectively. Solubility data have also been used to calculate the c.m.c. of Manoxol OT in aqueous solution. Small amounts of methanol in benzene enhance the solubility of cadmium soap in the latter solvent tremendously.