Peculiarities Of Triazoloazepinium Bromides Effect On Steel Microbial Corrosion

Triazoloazepinium bromides act as biocides against sulfate-reducing bacteria and can produce an effect on mild steel microbial corrosion.  It has been established that under the competing adsorption, the compounds with the properties of corrosion inhibitors can form a film, which protects the steel surface, before it is settled by corrosively active microorganisms.The protective film ensures the inhibition efficiency of up to 98.7%. With triazoloazepinium bromides of the 2nd group, corrosively active microorganisms colonize the steel surface before the inhibitor creates the protective layer. In this case, the biocorrosion accelerates by up to 6.25 times. Different effect of triazoloazepinium bromides on steel biocorrosion rate is explained by the molecular structure

Plasma-chemical Synthesis of Silver Nanoparticles in the Presence of Citrate

The contact non-equilibrium low-temperature plasma technique is used to synthesize silver nanoparticles (AgNPs) employing trisodium citrate as capping agent. The AgNPs were characterized using UV-Vis spectroscopy, scanning electron microscopy, X-ray diffraction and zeta potential analysis. Additionally, the antibacterial properties of the synthesized AgNPs were assessed

Plant Extract Based on Deep Eutectic Solvent-Mediated Biosynthesis of Silver Nanoparticles: Cytotoxicity and Antibacterial Effects

Deep eutectic solvent DES-based grape pomace extracts (GPE) were used to synthesize silver nanoparticles (AgNPs) for the first time. This paper presents a synthesis of AgNPs by a novel method with GPE obtained by an eco-friendly “green” solvent, namely, betaine-lactic acid and proline-lactic acid DESs. Compared with the water-based GPE, the DES-based grape pomace extracts contain lower reducing powers but additionally act as capping agent, which is the more important property for the creation of necessary particle nanosize and dispersion with colloidal stability. DESs were synthesized using a heating method, and Fourier transform infrared spectroscopy (FTIR) was carried out to confirm the formation of the DES. The phytochemical profile of GPE exhibits a high amount of hydroxycinnamic acids (23%), followed by anthocyanins (19%). The silver nanoparticles with a round shape were noticed on the scanning electron microscopy micrographs with the particle size in the range of 10–20 nm. The disc diffusion technique (DDT) showed that the AgNPs exhibited significant antibacterial activity against Gram-negative bacteria Escherichia coli (E. coli) UKM В-906 and Gram-positivespore-formingBacillus subtilis (B. subtilis) UCМ В-506T. Mitotic index (MI) and chromosomal aberrations (CAs) were assessed by A. cepa assay. The synthesized silver nanoparticles do not induce cytogenotoxic and genotoxic changes in Allium cepa L. with nanoparticles at concentrations up to 10%

Valorization of Food Waste to Produce Eco-Friendly Means of Corrosion Protection and “Green” Synthesis of Nanoparticles

Agrifood by-products are a key element within Europe’s sustainable strategies. Valorization and reuse of zero-waste technologies are becoming more popular, and they are commonly named as “second-generation food waste management.” The present study is directed to the valuable extracts of “green” organic compounds from the by-products of fruit and berry/vegetable crops, which can be revalorized in sustainable chemical technology and engineering, namely, in the production of “green” synthesis of nanoparticles and for the inhibition of corrosion and scaling of metals in corrosive media. Numerous types of agrifood by-products (rapeseed pomace, sugar beet pulp, fodder radish cake, grape pomace, and pomegranate peels) were investigated. The waste extracts for corrosion and scale inhibitors of mild steel in tap water were prepared by the conventional extraction method that uses 2-propanol and characterized by gas chromatography-mass spectroscopy (GC-MS). Inhibition of scaling and corrosion was investigated in thermal scaling conditions on the surface of the electrode manufactured from mild steel. The LPR technique was applied to measure the corrosion rate, and the scaling rate was determined gravimetrically. The extracts were found to inhibit the corrosion rate 2-3 times, while only radish cake extract inhibited both the corrosion and scaling rates. The waste extracts to produce nanoparticles were prepared by the ultrasound-assisted water extraction with subsequent oxidation by oxygen purge and characterized by liquid chromatography-mass spectroscopy (LC-MS). The aqueous grape pomace and pomegranate peel extracts were screened for total phenolic content (TPC) and total flavonoid content (TFC). The reduction capacity of the extracts was assessed using ferric reducing power (FRAP) and phosphomolybdenum (PM) assays. AgNPs were characterized by UV-Vis spectroscopy, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX) analysis. The particle size of AgNPs ranged between 40 and 50 nm. The antimicrobial activity of AgNPs was tested against Escherichia coli using the agar diffusion method and optical density

Mechanism of inhibitory action of fruit cake extracts as a new environmentally inhibitors of carbon steel corrosion

In this study the firstly study reported on the use of plum, cherry, nectarine and apple pomace extract as corrosion inhibitors of steel in water solution. Potentiodynamic polarization study showed that extracts act as a mixed type inhibitors with dominant cathodic effect. Linear polarization resistance method (LRP) assesses the time-related effect of inhibitors during open circuit potential corrosion. The results show that the inhibitory efficiency of our extract increases with increasing time formation protective film to reach 99 % in a concentration of 500 ppm. LC - MS and FTIR spectroscopy techniques can be concluded that several water-soluble interaction products of chemical reaction in NaCl are identified namely flavanol–anthocyanin and flavanol-aldehyde adducts. Subsequently, the iron-mediated complexation and oxidation of the extract components (flvonoids) in the aqueous solution were explored using UV-spectrophotometric and HPLC methods. With the passage of time, iron-mediated oxidative degradation and coupling reactions occurred, resulting in the production of hydroxybenzoic acid derivatives. Consequently, the inhibition decreased after 24 h. The chemisorption type of interaction of the product formed in the inhibited solution forming the adsorption-polymerization layer with the steel surface is established. Based on the quantum-chemically calculated parameters of the electronic structure of flavanol–anthocyanin and flavanol-aldehyde adducts, it was established for the first time that the combination of reactive fragments in them, which are spatially located in different planes with a higher quantity of hydroxyl groups, increases their adsorption activity and, as a result, their inhibitory capacity

Green Synthesis of Silver Nanoparticles Using Waste Products (Apricot and Black Currant Pomace) Aqueous Extracts and Their Characterization

An eco-friendly and low-cost method for synthesizing and capping silver nanoparticles with aqueous extracts of apricot and currant wastes is reported. The chemical profiles of the extracts were analysed using liquid chromatography-mass spectrometry (LC-MS). Total phenolic content and total flavonoid content of extracts were determined. The antioxidant activity of the synthesized nanoparticles was evaluated by DPPH (1,1-diphenyl-2-picrylhydrazyl) power assays. Cyclic voltammetry study was performed to determine the reducing ability of the aqueous extract of the black currant and apricot pomaces. Characterization of AgNPs was carried out using energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible spectroscopy. Zeta potential of obtained colloidal solutions varies from −33.41 to −24.23 mV indicating the moderate stability of synthesized nanoparticles. The synthesized nanoparticles efficiently demonstrated a bactericide effect on Escherichia coli

SYNTHESIS OF BACTERICIDAL MICROFILTRATION CERAMIC MEMBRANES: Received: 01st September 2021; Revised: 25th November 2021, 11th December 2021, 29th January 2022; Accepted: 05th February 2022

Membrane technologies have become widely used in filtration and separation processes in chemical, oil, food, pharmaceutical, medical, environmental, textile industries, etc. Recently, there is a growing demand for the use of bactericidal membranes due to their effectiveness in neutralizing microorganisms. The aim of this work is to synthesize microfiltration ceramic membranes modified with silver nanoparticles to provide them with bactericidal properties. In this work, ceramic membranes are synthesized by dry pressing followed by sintering from natural raw materials of Ukrainian origin, namely: kaolin and saponite, as well as with the addition of silicon carbide, sodium silicate, and calcium carbonate. To provide ceramic membranes with bactericidal properties, they were modified with particles of silver. The synthesized ceramic membranes were characterized by X-ray diffraction and fluorescence analysis, and their bactericidal ability has been established. The ceramic filtration membranes after modification by silvers exhibited an inhibitory effect on the growth of Gram-positive (B. subtilis.) and Gram-negative (Escherichia coli) pathogens. Thus, the obtained bactericidal ceramic membranes are of great interest for their use for biofouling control

Preparation of Silver Nanoparticles in a Plasma-Liquid System in the Presence of PVA: Antimicrobial, Catalytic, and Sensing Properties

The preparation of stabilized silver nanodispersions under the action of short-term plasma discharge using a polyvinyl alcohol stabilizer (polyvinyl alcohol (PVA)) was investigated. The influence of the basic technological parameters such as initial Ag+ concentration, PVA concentration, and process duration on the formation of nanoparticles and their characteristics (size and stability) were determined. The UV-Vis spectra showed the localized surface plasmon resonance at wavelengths of 400–420 nm. The SEM images showed that the shape of Ag NPs is spherical with an average particle size up to 30 nm. Ag NPs were used as a catalyst for the reduction of 4-nitrophenol (4-NP). The effect of the concentration of PNP and catalyst dosage on the value of apparent rate constant (kapp) for catalytic reduction of 4-NP in the presence of Ag NPs was investigated by means of UV-Vis spectrophotometry. The antimicrobial activity of Ag nanoparticles was investigated against yeast and Escherichia coli. The colorimetric sensor studies of plasma synthesized Ag NPs showed selective sensing of the potentially hazardous Hg2+ ion in water