Synthesis and Antibacterial Activity of (AgCl, Ag)NPs/Diatomite Hybrid Composite

In the present research, hybrid (AgCl, Ag)NPs/diatomite composites were synthesized by direct impregnation with aqueous silver nitrate solutions. The silver chloride nanoparticles (AgCl-NPs) were formed as an effect of the exchange reaction when silver interacted with the diatomite mineral impurity halite. Nanoparticles of metallic silver (AgNPs) were created by the reduction of silver ions under the influence of hydrogen peroxide. The content of silver chloride nanoparticles in the (AgCl, Ag)NPs/diatomite composite was limited by the content of the halite in the used diatomite. Samples of natural diatomite and synthesized (AgCl, Ag)NPs/diatomite composites were examined by using scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, infrared spectroscopy and thermogravimetric analysis. Moreover, the antibacterial potential of synthesized composites was also studied using the MIC (minimal inhibitory concentration) method against the most common drug-resistant microorganisms in the medical field: Gram-positive Staphylococcus aureus and Gram-negative Klebsiella pneumoniae. The obtained hybrid (AgCl, AgNPs)/diatomite composites were shown to have antimicrobial potential. However, widespread use requires further study by using various microorganisms and additional cytotoxic studies on eukaryotic systems, e.g., cell lines and animal models

Preparation of nanocomposite silver/kaolin with antibacterial properties

In this study, a nanocomposite based on kaolin from the Alekseevsky deposit (Kazakhstan), containing nano-silver particles, was synthesized. Kaolin has good physical and chemical properties and is an effective carrier for medicines. The synthesis of AgNPs/kaolin nanocomposites was carried out by chemical reduction. Impregnation of silver nanoparticles into silica matrix can prevent the agglomeration of mobile ions, and thereby preserve the antibacterial activity of the compound. The composition and structure of the resulting nanocomposite were studied using SEM/EDS analysis to study the morphology and elemental composition of natural and silver-modified kaolin, the specific surface was determined by the BET method, and functional groups were identified by IR spectroscopy. The resulting composite was tested for antibacterial activity against Gram-negative and Gram-positive bacteria (E.Сoli, S. Aureus)