Coprecipitation of Nanocomposites Based on Colloidal Particles of Sulfur and Carbonates of Alkaline-Earth Metals from Polysulfide Solutions

It has for the first time been shown that the action of carbon dioxide on solutions of alkaline-earth metal polysulfides causes a reaction yielding nanoparticles of sulfur and calcium, barium, and strontium carbonates. It has been found that, initially, particles of sulfur and a corresponding carbonate are synthesized with average sizes of about 20-25 nm; then, the particles are enlarged (aggregated) with the precipitation of a composite, which consists of hydrophobic particles of sulfur and the carbonate (the latter become hydrophobic due to the adsorption of neonol present in the reaction mixture). It has been shown that only sulfur exhibits antifungal activity in the composites, while carbonates have no effect on pathogenic fungi. The composite consisting of sulfur and calcium carbonate nanoparticles has shown the highest biological activity during germination of wheat seeds.