This study investigates the potential of dandelion (Taraxacum officinale) root ethanol extract as a green corrosion inhibitor for two types of steel (TH-550 and TS-275) in a chloride-rich environment. Steel samples were chemically prepared and immersed in a 3% NaCl solution, both without and with the extract at concentrations of 0.5, 1.0, and 1.5 g/L. Morphology and composition of steel samples after 24 h in blank and inhibited solutions, examined by SEM and EDX, revealed the inhibitive effect of dandelion extract, since corrosion products were not visible on the steel surfaces after 24 h in the inhibited solution, unlike the blank steel surfaces. Based on the weight loss, dandelion extract inhibited corrosion processes of S2 in a chloride-rich environment at all examined concentrations; on the other hand, it acted as a corrosion inhibitor of S1 in 3% NaCl only at the concentrations of 1.0 and 1.5 g/L. According to corrosion current, corrosion potential and polarization resistance determined by potentiodynamic tests, dandelion root extract is a mixed corrosion inhibitor with a dominant anodic reaction, which decreases corrosion rate by adsorbing onto anodic sites and prevents steel dissolution. According to ATR-FTIR analysis, hydroxyl groups within the inulin molecule could act as the dominant metal-complexing groups. Therefore, the adsorption properties of dandelion root extract are most probably related to this specific site. Based on electrochemical impedance spectroscopy, the enhancement of corrosion resistance in the steel samples was evident in all the inhibited solutions examined compared to a pure 3% NaCl solution.

The present paper aims to discover the optimal conditions for ultrasound-assisted extraction (UAE) of (poly)phenolic chemicals from blueberry (Vaccinium myrtillus) leaves. UAE was performed under the following process conditions: temperature: 25?65?C, ethanol concentration in the extraction solvent: 30?90 vol.%, and solid-to-solvent ratio: 1:15?1:45 w/v. Statistical analysis was performed using Design-Expert software, using the Box-Behnken design. The study''s responses were the content of total (poly)phenols, flavonoids, and anthocyanins in the derived extracts. The results indicated that the corresponding response surface models were highly statistically significant (p < 0.0001) and sufficient to describe and predict the content of total (poly)phenols, the content of flavonoids, and the content of anthocyanins with R2 of 0.965, 0.980 and 0.972, respectively. The optimal conditions for the extraction are for total (poly)phenols 48.4 ?C, 51.3 vol.% ethanol, and 1:43.8 w/v solid-to-solvent ratio; flavonoids 58.5?C, 48.0 vol.% ethanol, and 1:29.8 w/v ratio; and anthocyanins 64.2?C, 73.5 vol.% ethanol, and 1:44.7 w/v ratio. The use of UAE enhances extraction yields by increasing the release of bioactive compounds, while the application of the Box-Behnken design allows for precise determination of optimal extraction parameters, thereby achieving maximum yields and efficiency

This study investigates the potential of Taraxacum officinale (TO) root extract as an environmentally friendly corrosion inhibitor for two types of steel, TH-550 and TS-275, in an acidic environment. The corrosion inhibition was assessed by monitoring the weight loss of steel samples over a 72-hour immersion period in four different solutions: blank 4% HCl solution and 4% HCl solutions containing 0.5, 1.0, and 1.5 g/L of TO root extract. The inhibitor efficiency, calculated from weight loss data, ranged from 70% to 89%. Surface analysis of the steel samples, conducted after 24 hours of immersion, revealed the formation of a uniform protective film on the steel exposed to the inhibited solutions, while samples in the blank acidic solution showed significant corrosion. Fourier-transform infrared spectroscopy analysis identified key metal-complexing functional groups in the TO root extract, including aromatic C—H, C—O, C=O, and O—H, which are likely responsible for the interaction with the steel surface. Potentiodynamic polarization measurements indicated that the TO root extract acts as an anodic corrosion inhibitor, with the ability to cover up to 88% of the steel surface. Electrochemical impedance spectroscopy, in combination with polarization and weight loss results, demonstrated that the inhibitor efficiency of the TO root extract increases with concentration.

Achieving the superior properties of nanocomposite materials involves addressing several challenges, particularly the agglomeration of nanoparticles in the plating bath. This study focuses on the electrodeposition and characterization of Zn-Co-CeO2 composite coatings using a particle-free plating bath, an effective strategy for mitigating agglomeration. For comparison, the composite coatings were also deposited from a traditional biphasic plating solution. The coatings were deposited galvanostatically at various current densities. Scanning electron microscopy revealed that using a particle-free plating solution in conjunction with lower current densities enhanced the compactness and the overall quality of the coatings. Lower current densities favoured the codeposition of particles, as indicated by energy-dispersive X-ray spectroscopy results. Notably, the coatings produced from the particle-free bath exhibited significantly improved corrosion resistance and durability in chloride-rich environments, attributed to their self-healing properties, as shown by electrochemical impedance spectroscopy.

The study examined the inhibitive effect of thyme extract as a green inhibitor on the corrosion of two steel types, steel 1 - DC01 and steel 2 - X5 CrNi 18-10, in a 3% NaCl solution. Four test solutions were used: 1) blank 3% NaCl, 2) 3% NaCl + 0.5 g/L thyme extract, 3) 3% NaCl + 1.0 g/L thyme extract, and 4) 3% NaCl + 1.5 g/L thyme extract. Steel samples (3x3x0.2 cm) underwent chemical treatment before being exposed to the non-inhibited and inhibited solutions. Weight loss and electrochemical techniques, i.e. electrochemical impedance spectroscopy, were employed to investigate the corrosion rate and the inhibitive effect of thyme extract. All experiments were obtained on room temperature. After chemical treatment samples were immersed in blank and inhibited solutions for 2h, 4h, 6h, 8h, 24h, 48h и 168h. Based on the weight loss in steel samples for the time spent in prepared solutions, negative mass index of corrosion, Km - (g/m2h), depth corrosion indicator, π (mm/year), and degree of efficiency, protection factor, z (%), were calculated. The results of the gravimetric and electrochemical measurements showed that thyme extract had an inhibitive effect on the corrosion of the tested steels, but not sufficient to be recommended for commercial application. The average corrosion inhibition efficiency of thyme extract was below 60% for both steel types. For steel 1, the protection factor was above 80% only in solution 4 after 48h and 168h, while for steel 2, the protection factor was greater than 80% for all three inhibited solutions only after 168h. These findings suggest a very slow adsorption of phytochemicals from thyme extract on the surface of the tested steels.