Corrosion Inhibition of Rumex vesicarius Mediated Chitosan-AgNPs Composite for C1018 CS in CO2-Saturated 3.5% NaCl Medium under Static and Hydrodynamic Conditions

Rumex vesicarius (RVE) mediated chitosan–AgNPs composite was produced in situ by using an aqueous extract of Rumex vesicarius leaves as the reducing agent to reduce Ag+ to Ag0. The synthesized composite was evaluated as a sweet (CO2) corrosion inhibitor (CI) for C1018 carbon steel (CS) in 3.5 wt% NaCl solution under static and hydrodynamic conditions. The corrosion inhibitive performance was evaluated using electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR), and potentiodynamic polarization (PDP) techniques, as well as scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDAX), and atomic force microscopy (AFM) on corroded C1018 CS without and with additives. The effect of concentration, immersion time, temperature, and rotation speed on the CI performance of the composite was also investigated. The corrosion inhibitive effect increased with increasing composite dosage, with the highest inhibition efficiency (IE) acquired at the maximum composite dosage of 0.3%. Beyond this concentration, the IE decline with increasing concentration. Furthermore, IE was found to increase with immersion time and decline with a temperature rise from 25 to 40 �C, with the optimum temperature of 60 �C found to accelerate corrosion without and with RVE-mediated Chi–AgNPs composite. Under high shear stress, the Chi–AgNPs composite exhibits moderate corrosion inhibition under hydrodynamic conditions. The surface analysis results validate the formation of a protective covering due to composite adsorption on the CS surface. The RVE-mediated chitosan–AgNPs composite could be recommended as a CI for C1018 CS in sweet (CO2) corrosion environments at ambient temperatur

Exploration of natural polymers for use as green corrosion inhibitors for AZ31 magnesium alloy in saline environment

Seven natural polymers namely, chitosan (CHI), dextran (Dex), carboxymethyl cellulose (CMC), sodium alginate (ALG), pectin (PEC), hydroxylethyl cellulose (HEC), and Gum Arabic (GA) were screened for anticorrosion property towards AZ31 Mg alloy in 3.5 wt.% NaCl solution. CHI, Dex, CMC, PEC, and GA accelerated the corrosion while ALG and HEC moderately inhibited the corrosion of the alloy. HEC and ALG (1 g/L) protected the alloy by 64.13 % and 58.27 %, respectively. Two inhibitor cocktails consisting of either HEC or ALG, KI, and Date palm seed oil have been formulated. HEC- and ALG-formulations inhibited the alloy corrosion by 80.56 % and 77.43 %, respectively from EIS technique. Surface observation studies using SECM, AFM, SEM, and EDX agreed with other experimental results revealing effective corrosion inhibition by the formulations. X-ray photoelectron spectroscopy, FTIR, and UV–vis results disclose that Mg(OH)2 co-existed with adsorbed inhibitor complexes

Preparation of Silver/Chitosan Nanofluids Using Selected Plant Extracts: Characterization and Antimicrobial Studies against Gram-Positive and Gram-Negative Bacteria

Chitosan/silver nanofluids were prepared using Phoenix dactylifera (DPLE) or Rumex vesicarius (HEL) extracts as the reducing agent, characterized using Fourier-transform infrared spectroscopy (FTIR), ultraviolet–visible (UV-vis), X-ray di�raction (XRD), and transmission electron microscope (TEM). The antimicrobial e�ect of the nanofluids against Gram positive, Bacillus licheniformis, Staphylococcus haemolyticus, Bacillus cereus, and Micrococcus luteus, and Gram-negative Pseudomonas aeruginosa, Pseudomonas citronellolis, and Escherichia coli bacteria has been studied. The nanoparticles were polydispersed in the chitosan matrix and are highly stable. The zeta potential of the silver nanoparticles in DPLE- and HEL-mediated composites is +46 mV and +56 mV, respectively. The FTIR results reveal that the free carboxylate groups in the plant biomaterial took part in stabilization process. HEL is a stronger reducing agent than DPLE and nanoparticles generated with HEL are smaller (8.0–36 nm) than those produced with DPLE (10–43 nm). DPLE- and HEL-mediated composites e�ectively inhibit the growth of the studied bacteria but HEL-mediated composite exhibited higher e�ect. The higher antimicrobial activity of HEL-mediated composite is linked to the smaller nanoparticles. The foregoing results indicate that HEL extract can be used in the green production of potential antimicrobial chitosan/silver nanofluids for biomedical and packaging applications

Comparative studies on the corrosion inhibition efficacy of ethanolic extracts of date palm leaves and seeds on carbon steel corrosion in 15% HCl solution

The work reports on the study carried out to comparatively assess the corrosion inhibition efficacy of crude ethanolic extracts of date palm leaves and seeds on X60 carbon steel corrosion in 15% HCl solution at 25–60 °C. The corrosion inhibition studies was carried out using weight loss and electrochemical (potentiodynamic polarization and linear polarization resistance) techniques. Preliminary phytochemical screening was performed in order to determine the phytoconstituents present in the crude extracts. The influence of extractive solvents on the corrosion inhibition performance of the extracts was also investigated. It is found that the crude extracts of both date palm leaves and seeds contain saponins, flavonoids, cardiac glycosides and reducing sugars. Tannins is only present in the leaves and absent in the seeds while anthraquinones is absent in both extracts. The crude ethanolic extracts inhibited the corrosion of X60 steel in the aggressive 15% HCl solution with the leaves extract showing superior performance. Inhibition efficiency increased with increase in concentration of the extracts and temperature. Potentiodynamic polarization results reveal that the extracts function as mixed type inhibitors. Corrosion inhibition occurs by virtue of adsorption of components of the extract on the steel surface and was found to follow Langmuir adsorption isotherm model. On the influence of the extractive solvents on the corrosion inhibition performance, the order of inhibition efficiency at 60 °C follows the trend DPLAE (73.6%) > DPLEE (62.5%) > DPSAE (59.9%) > DPSEE (55.9%) with the optimum extract concentration (2000 ppm) studied

A critical review on the recent studies on plant biomaterials as corrosion inhibitors for industrial metals

Plant biomaterials as inexpensive, nontoxic, biodegradable materials are found abundantly in nature. They contain heteroatoms and/or pi electrons that make them candidate for metals corrosion inhibitor. In recent years, numerous research works have been undertaken on plant biomaterials as metals corrosion inhibitor in different corrosive media. This review critically looks at the researches done in the years 2013–2018. Corrosive environments covered include acidic, basic, neutral, aqueous, geothermal fluid and artificial saliva. The major findings and the mechanism of inhibition has been elucidated. The missing gap in this area of research has been pointed out and future direction proposed

Effect of Intensifier Additives on the Performance of Butanolic Extract of Date Palm Leaves against the Corrosion of API 5L X60 Carbon Steel in 15 wt.% HCl Solution

The quest to replace toxic chemicals in the nearest future is revolutionizing the corrosion inhibitor research world by turning its attention to plant biomaterials. Herein, we report the corrosion inhibiting potential of butanolic extract of date palm leaves (BUT) on the corrosion of API 5L X60 carbon steel in 15 wt.% HCl solution. The mass loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), linear polarization (LPR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX), and atomic force microscopy (AFM) techniques were employed in the investigation. We also report the effect of intensifier additives, namely formic acid (FA), potassium iodide (KI), and zinc nitrate (Zn(NO3)2) as well as temperature on the corrosion inhibiting performance of BUT. BUT exhibits inhibiting ability but the extent of inhibition is dependent on concentration, temperature, and intensifiers’ concentration. At 25 �C, 200 mg/L BUT and 700 mg/L BUT protected the carbon steel surface by 50% and 88%, respectively. The addition of 3 mM FA and 5 mM KI to 200 mg/L upgraded the extract performance to 97% and 95%, respectively. Zn(NO3)2 performs poorly as an intensifier for BUT under acidizing conditions. The adsorption of BUT + FA and BUT + KI is synergistic in nature whereas that of BUT + Zn(NO3)2 drifts towards antagonistic behavior according to the calculated synergism parameter. Increase in the system temperature resulted in a slight decline in the inhibition efficiency of BUT + FA and BUT + KI but with efficiency of above 85% achieved at 60 �C. The SEM and AFM results corroborate results from the electrochemical techniques

Corrosion inhibition effect of a benzimidazole derivative on heat exchanger tubing materials during acid cleaning of multistage flash desalination plants

A benzimidazole derivative, 2-(2-bromophenyl)-1-methyl-1Hbenzimidazole (2BPB) has been studied as a corrosion inhibitor for Cu-Ni 70/30 and 90/10 alloys in 1 mol/dm3 HCl solution at low and high temperatures using the weight loss, electrochemical (potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), & cyclic voltammetry (CV)), and surface characterization (scanning electron microscopy (SEM) & Fouriertransform infrared spectroscopy (FTIR)) techniques. The effect of immersion time (up to 72 h) and addition of iodide ions on the inhibition efficiency of 2BPB have also been investigated. At low temperature, 1.0 g/L 2BPB inhibits Cu-Ni 70/30 and 90/10 alloys by 88.9 ± 4.8% and 57.5 ± 1.3%, respectively. The performance of 2BPB improves with increase in immersion time and addition of iodide ions but slightly depreciates with rise in temperature. 2BPB acts as a mixed type corrosion inhibitor and adsorbs on the alloys surfaces through physical adsorption mechanism. SEM and FTIR results confirm the adsorption of 2BPB on the alloys surfaces. 2BPB is a potential low toxic candidate for the formulation of acid corrosion inhibitor for Cu-Ni alloys

Studies of the anticorrosion property of a newly synthesized Green isoxazolidine for API 5L X60 steel in acid environment

tThe potential of an environmentally friendly novel synthesized and characterized isoxazoli-dine derivative namely 5-(4-dodecyloxy-3-methoxybenzyl)-2-methylisoxazolidine (DMBMI)as anticorrosion agent for carbon steel in 1 mol/L HCl solution was investigated using gravi-metric and electrochemical techniques. Kinetics parameters of the corrosion process andthe thermodynamic data of adsorption of the organic molecule on the carbon steel surfacewas also assessed in order to characterize the performance of the studied compound as acorrosion inhibitor. The solubility, toxicity and the state of the molecule at the acidic pH(1 mol/L HCl) was predicted. It was found that the synthesized compound is green (envi-ronmentally friendly) with an optimum solubility of 23.8 mg/L. Also the molecule exists100 percent in protonated form in 1 mol/L HCl (pH = 0). The molecule possesses anticorro-sion property against steel corrosion in acid environment. Corrosion retardation efficacy isdependent on concentration and temperature. DMBMI exhibited concentration dependentcorrosion inhibition ability influencing mainly anodic metal dissolution based on potentio-dynamic polarization data. Addition of KI through the mechanism of competitive adsorptionenhanced the inhibition efficiency considerably. The active sites for the interaction of DMBMIwith steel surface was calculated using quantum chemical method while the adsorptionenergy between the inhibitor and steel surface was derived via Monte Carlo simulations.Results from theoretical studies and surface analysis are in conformity and reveal that theO and N heteroatoms in the synthesized molecule are the interaction centers

Development of a green corrosion inhibitor for use in acid cleaning of MSF desalination plan

A green and cost-effective inhibitor based on Date palm leaves extract was formulated for use during acid cleaning of thermal desalination plants. The inhibitor formulation designated as F1 was tested against the corrosion of ferrous-based alloys namely: carbon steel, Ni-resist, and 316L stainless steel in 2% HCl solution at 40 °C under static and hydrodynamic conditions. Weight loss and electrochemical methods complemented with scanning electron microscopy were used in the study. Experiments were performed for 6, 24, and 72 h and the performance of F1 was compared with that of a commercial acid corrosion inhibitor. F1 exhibited excellent corrosion inhibition performance. Under static and dynamic conditions, 0.4% of F1 provided excellent corrosion inhibition up to 72 h and comparable to the commercial inhibitor performance. The inhibitors (F1 and the commercial one) exhibited a behavior typical of a mixed type corrosion inhibitor in the studied environment according to the potentiodynamic polarization. Results from cyclic potentiodynamic polarization experiments excluded pitting corrosion risk on the 316L stainless steel in the studied medium. Results from all applied techniques are in good agreement

Elucidation of corrosion inhibition property of compounds isolated from Butanolic Date Palm Leaves extract for low carbon steel in 15% HCl solution: Experimental and theoretical approaches

The present work reports on the corrosion inhibition property of compounds isolated from butanolic extract of Date Palm leaves for low carbon steel in 15% HCl solution. Six compounds were isolated from Date Palm leaves and purified using a combination of column chromatography, thin layer chromatography, and Prep HPLC-MS system. The isolated compounds were characterized using 1H NMR, 13C NMR, and GC–MS. Their identity was revealed to be a mixture of fatty alkanes, oleanolic acid (OA), vanillyl alcohol (VA), b-Sitosterol-3-O-b-D-glucoside (b-SSG), sucrose sugar, and carotenoid lutein. As a result of the amount of the different isolates obtained, only three out of the six compounds namely b-SSG, OA, and VA were tested for anticorrosion property for low carbon steel in 15% HCl. The corrosion inhibition of the isolated compounds was performed using weight loss and electrochemical techniques. Surface morphology analysis of the corroded steel in the absence and presence of the isolated compounds was undertaken using SEM/EDAX and 3D optical profilometer. Also, DFT calculations was performed in order to indicate the reactivities and bonding sites of the isolated molecules as well as Monte Carlos simulations (MCS) to determine the energy of interaction between the inhibitors and carbon steel surface. Results obtained show that the values of inhibition efficiency (IE) for the different isolated compounds at the concentration (35 ppm) studied follow the trend: b-SSG (46.57%) > VAisolated (39.30%) > VAcommercial (36.81%) > OA (31.94%) at 25 �C. It is also noted that, for the isolated OA, IE increased with increase in concentration but decreased with increase in temperature. For isolated VA, IE decreased with increase in temperature. However, for the commercial VA, IE slightly increased with rise in temperature. The experimental results are in agreement with the theoretical prediction. In both predicted and experimental results, b-SSG is the best corrosion inhibitor