Aggregation Behavior and Catalytic Action of Carbamate-Bearing Surfactants in Aqueous Solutions.

Mirgorodskaya, A. B.; Kushnazarova, R. A.; Kuznetsov, D. M.; Tyryshkina, A. A.; Zakharova, L. Ya.

The aggregation behavior of new cationic hexadecyl surfactants with one or two alkylcarbamate fragments in the head group in water was studied using conductometry, spectrophotometry, fluorescence spectroscopy, and dynamic light scattering, and their catalytic action in hydrolytic processes was examined. Kinetic parameters of the alkaline hydrolysis of carboxylic acid esters (p-nitrophenyl acetate and p-nitrophenyl caprinate) were obtained upon the variation of the structures of surfactant head groups and the pH of solution. It was shown that the catalytic effect of micelle-forming surfactants with a single carbamate fragment is higher than that of the corresponding dicarbamate compounds, and it decreases with the alkyl chain length of substituents in head groups. It was found that carbamate surfactants capable of vesicle formation accelerate the hydrolysis of the test esters to a greater extent than their analogs forming micelles: the observed acceleration of the process can exceed two orders of magnitude in the case of a compound with the decyl substituent in a carbamate fragment.

SURFACE active agents; CATIONIC surfactants; AQUEOUS solutions; CATALYSIS; ESTERS; HYDROLYSIS; LIGHT scattering

Kinetics & Catalysis, 2022, Vol 63, Issue 3, p261

0023-1584

Academic Journal

10.1134/S0023158422030065