No abstract

No abstract

In this work the peculiarities of phase formation of the cement stone at presence of nanostructured modifier of the silica composition were identified using the method of x-ray diffraction and raster electronic microscopy. Also the character of influence of modifier on the structure formation of the cement stone was defined. Polydisperse modifier with the presence of a highly active colloidal component, on the one hand, acts as a pozzolanic component, and on the other hand – as a submicron filler.

This article proposes a method for silver nanoparticle (AgNP) stabilization in polymer coatings obtained from aqueous acrylic dispersions. The main objective of the study was to improve the biocidal properties of coatings using AgNPs due to the preservation of their nanoscale state. Two types of AgNP solutions with fundamentally different stabilization mechanisms were synthesized and compared. Two mechanisms were determined: an aqueous electrostatic mechanism with sodium docusate stabilizer (AOT) and a steric, propylene glycol with polyvinylpyrrolidone (PVP) stabilizer. The results showed that both solutions were unstable and prone to precipitation as early as the first day after synthesis. However, the saturation of the propylene glycol AgNP solution with ammonium hydroxide to pH < 9 allowed the strengthening of the electrostatic factor of aggregative stability, providing optimal conditions for mixing with acrylic dispersions stabilized by anionic surfactants. The obtained AgNPs in the acrylic dispersions stabilized over time, and when they became film-forming, stable AgNPs (~20-30 nm) occurred on the surface. As a result, the developed coatings using AgNPs synthesized in propylene glycol in the presence of non-ionic PVP and modified with ammonium hydroxide, demonstrated a high inactivation of bacteria colony-forming units (CFU) (> 60%) within 60 min of contact compared to aqueous AgNP solutions using anionic surfactants as stabilizers, where the decrease in CFU was around 25%.

No abstract