HYBRID NANOCOMPOSITES OF METHYLCELLULOSE: PHYSICO-CHEMICAL AND ANTIMICROBIAL PROPERTIES

Abstract

"Stabilized silver nanoparticles were obtained in the presence of a reducing agent – NaBH4 and a stabilizer – methylcellulose, at 40 °C and pH = 5.35-11. The stabilizing role of the polymer is shown, as it prevents the oxidation and agglomeration of nanoparticles. It was found that the synthesis pH is an important factor in the formation of stable nanoparticles, which contributes to the regulation of their hydrodynamic radius. The results of UV spectroscopy established that the synthesized samples of silver nanoparticles achieve aggregative stability within 96 hours. Solutions and films of hybrid nanocomposites were comprehensively investigated by spectral, XRD and thermal studies. The diffractogram of silver NPs, corresponding to JCPDS No. 04-0783, was confirmed by the XRD method. In the studied pH range, the hydrodynamic radius and distribution of Ag NPs in methylcellulose solutions had a polymodal character, and an increase in pH to 9–11 led to an increase in particle aggregation. It was found that stabilized silver nanoparticles showed antimicrobial activity against microorganisms – Streptococcus salivarius, Staphylococcus saprophyticus, Streptococcus mitis and Proteus vulgaris, with the formation of an inhibitory zone in the range of 15.0±0.2÷20.0±0.4 mm. The synthesized samples are of applied interest in the development of antibacterial drug systems."