Study of aggregative stability of selenium nanoparticles stabilized with cocamidopropylamine oxide

In this work, samples of selenium nanoparticles stabilized with cocamidopropylamine oxide were obtained by chemical reduction in an aqueous medium. Quantum chemical modeling of the process of stabilization of selenium nanoparticles by cocamidopropylamine oxide molecules was carried out, as a result of which it was found that this interaction is energetically favorable (∆E ≥ 2399.568 kcal/mol) and chemically stable (0.035 ≤ n ≤ 0.067 eV), and the interaction of the selenium atom with cocamidopropylamine oxide through a secondary amino group (∆E = 2400,099, n = 0.067 eV). As a result of optimization of the synthesis method, optimal concentrations of selenic acid, ascorbic acid and cocamidopropylamine oxide were determined – 0.004, 2.118 and 0.180 mol/dm³. The stability of selenium nanoparticles was also studied depending on the active acidity of the medium and the ionic strength of the solution. It has been established that selenium particles have high stability in the pH range of the medium from 1.81 to 4.56 (from 12 ± 2 nm to 24 ± 5 nm). Based on the analysis of the dependences of the average hydrodynamic radius on the ionic strength, it was found that Na⁺ and Cl^- ions do not significantly affect the stability of the particles (R varies from 12 ± 2 to 15 ± 2 nm), and selenium nanoparticles are stable when SO₄^2– ions with concentrations up to 0.5 mol/dm³ are added to the sol.