Synthesis and study of disperse characteristics of selenium nanoparticles stabilized by octadecyltrimethylammonium bromide

Abstract

Within the framework of this work, the optimization of synthesis and study of dispersive characteristics of selenium nanoparticles stabilized by octadecyltrimethylammonium bromide was carried out, and the study of the aggregate stability of the obtained nanoparticles from the active acidity of the pH of the medium was carried out. At the first stage, quantum-chemical modeling of the interaction process of selenium nanoparticles stabilized by octadecyltrimethylammonium bromide was carried out, which resulted in the establishment that the addition of octadecyltrimethylammonium bromide forms an energetically favorable and chemically stable interaction. The interaction of OTAB with selenium occurs through the quaternary amino group and is energetically favorable (Delta E > 2399 kcal/mol) and chemically stable (0,031 <= eta <= 0,057 eV). The synthesis was carried out using a chemical reduction method in an aqueous environment. Solution of selenous acid and octadecyltrimethylammonium bromide was prepared at a constant temperature and stirred, and a separate solution of the reducing agent, selenous acid, was added to the precursor solution with a stabilizer. The synthesis was optimized using an experimental design matrix with varying concentrations of system parameters. The samples were studied using photon correlation spectroscopy and acoustic electron spectroscopy. As a result of the research, it was found that the optimal sample has an average hydrodynamic diameter of 36 nm and a zeta-potential value of 46 mV. Then, the coagulation stability of selenium nanoparticles stabilized by octadecyltrimethylammonium bromide was studied in relation to changes in the pH of the medium. To conduct the study, buffer solutions with pH values ranging from 1,81 to 11,98 were prepared. The obtained samples of selenium nanoparticles stabilized by octadecyltrimethylammonium bromide were mixed with buffer solutions in a 1:1 ratio. As a result of the studies of the obtained samples, it was found that the change in the active acidity of the pH of the medium does not have a significant effect on the values of the average hydrodynamic diameter and zeta-potential of the samples at any point in the selected pH range of the medium.