English English

Erasov V.S.

Candidate of Chemical Sciences (Ph.D.), Lecturer, Lomonosov Institute of Fine Chemical Technologies, MIREA – Russian Technological University

Surface-active and micelle-forming properties of binary mixtures of glycyrrhizin and decyl glycoside and stabilization of foam stabilized by such a mixture with xanthan and keratin additives

,
 27-42 p.
Abstract
The surface and micelle-forming properties of two surface-active sugar derivatives and their binary mixtures were studied: dipotassium glycyrrhizinate, which is an anionic surfactant of natural origin (saponin) and has biologically active properties, and a nonionic sugar surfactant decyl glycoside. Decyl glycoside has a noticeably higher surface activity and a noticeably lower CMC value than dipotassium glycyrrhizinate. Using Rubin's equations, the composition of mixed micelles and the parameters of surfactant interaction in them were calculated. It has been shown that a synergistic effect is observed in aqueous solutions of binary mixtures of these surfactants. Due to this, dipotassium glycyrrhizinate can be used together with decyl glycoside as a base for foaming solutions for cosmetic, pharmaceutical and medical foams. Using dispersion analysis of foam over time, the stability of foam stabilized with a mixture of dipotassium glycyrrhizinate and decyl glycoside in a molar ratio of 0.2:0.8 and the ef-fect on the stability of foam of the addition of two different biopolymers: polysaccharide - xanthan (xanthan gum) and protein - keratin of sheep wool hydrolyzate were studied. Based on dispersion analysis of foam micrographs, it was shown that both polymers increase the durability of the foam over time. Foam containing xanthan breaks down primarily through Ostwald ripening rather than coalescence. Foam with keratin hydrolyzate has a lower initial dispersion and number of bubbles than foam with keratin hydrolyzate. The stability of both foams is close, but slightly higher in the case of the addition of keratin.
PDF

Adsorption of kappa-carrageenan on the surface of chitosan and its sulfuric acid salt and stabilization of chitosan-sulfate nanoparticles by it

,
 5-18 p.
Abstract
Objectives: to investigate the adsorption of k-carrageenan on the surface of chitosan at pH 7.4 and chitosan treated with dilute sulfuric acid solution (pH 2.5-2.7). To develop a method for obtaining the sol of the chitosan sulfate salt - chitosan sulfate (CX) and to investigate its stability in time depending on the use of various acids as precursors, and its increase with the addition of different concentrations of k–carrageenan.
Methods. To determine the viscosity of polymer solutions, their molecular weight and to study the adsorption of k-carrageenan on CX, the method of capillary viscometry was used. The assessment of the stability of the zones over time was carried out photometrically.
Results. The adsorption of k-carrageenan on chitosan and CX has been studied: experimental isotherms of k-carrageenan adsorption have been constructed.on the surfaces of chitosan and CX, the constants of the Langmuir equation are calculated and complete theoretical adsorption isotherms are constructed using them. A method for obtaining a CX hydrosol with a positive particle charge has been developed. The stability of CX sols in time both without additives and with additives of k-carrageenan in time has been studied.
Conclusions. The adsorption of k-carrageenan on chitosan and CX is monomolecular. The adsorption equilibrium constant is greater with the adsorption of k-carrageenan on the surface of CX, and the maximum adsorption value is greater with the adsorption on the surface of chitosan. Of the acids used as precursors, the sol obtained using citric acid has the greatest stability. With an additional additive to the sols of the protective colloid - k-carrageenan to sols obtained using hydrochloric acid and citric acid, the sol obtained with the use of hydrochloric acid and carrageenan additives in the range of 0.04-0.06% has the greatest aggregate stability.
PDF