SYNTHESIS AND CHARACTERIZATION OF SELENIUM NANOPARTICLES STABILIZED WITH DIDECYLDIMETHYLAMMONIUM CHLORIDE

Abstract

As part of this work, a synthesis procedure was developed and the characteristic of selenium nanoparticles stabilized with didecyldimethylammonium chloride (DDAC) was carried out. Nanoparticles were obtained by chemical reduction in an aqueous medium. Selenous acid was used as a selenium-containing precursor, ascorbic acid was used as a reducing agent, and didecyldimethylammonium chloride was used as a stabilizer. To determine the optimal parameters for the synthesis of selenium nanoparticles stabilized with didecyldimethylammonium chloride, a multifactorial experiment was carried out. The input parameters were the concentration of selenous acid, the concentration of didecyldimethylammonium chloride (DDAC) and the concentration of ascorbic acid. The average hydrodynamic radius of selenium particles, which was determined by the method of dynamic light scattering, was considered as an output parameter. The optimal parameters for the synthesis of selenium nanoparticles (R from 15 to 25 nm) have been established: reducing agent concentration – from 1.076 mol/l to 2.118 mol/l, stabilizer concentration – from 0.006 mol/l to 0.085 mol/l, precursor concentration – from 0.004 mol /l to 0.236 mol/l. At the next stage of research, the effect of solution pH on the average hydrodynamic radius of selenium nanoparticles was determined. It was shown that in the pH range from 1.81 to 2.21, the average hydrodynamic radius of selenium nanoparticles does not change significantly, which indicates the aggregative stability of selenium nanoparticles in this range. In the pH range from 2.21 to 4.56, there is a sharp increase in the average hydrodynamic radius from 21 to 497 nm. At pH ˃ 7.96, coagulation of selenium particles is observed.