Fig 11 - uploaded by I.O. Arukalam
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Electronic properties of hydroxyethyl cellulose (HEC): (a) Optimized structure, (b) Total electron density, (c) HOMO Orbital, (d) LUMO Orbital, (e) Fukui function for Nuclephilic attack and (f) Fukui function for electronic attack.
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The inhibitive effect of hydroxyethyl cellulose (HEC) on mild steel corrosion in aerated 0.5 M H2SO4 solution was studied using gravimetric and electrochemical techniques. The effect of temperature on corrosion and inhibition was also investigated. The results show that hydroxyethyl cellulose functioned as a good inhibitor in the studied environmen...
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Citations
... The theory supports this supposition: the HEC used has a moderate residual ring -OH (DS 3 -1.52 = 1.48; and many of these are less reactive 3-OH groups) (Fabbri et al., 2002;Fox et al., 2011). The terminal oligo (hydroxyethyl) hydroxy groups also have wider approach angles and so are much more reactive than ring hydroxy Arukalam et al., 2014). ...
In situ forming hydrogels are promising for biomedical applications, especially in drug delivery. The precursor solution can be injected at the target site, where it undergoes a sol-gel transition to afford a hydrogel. In this sense, the most significant characteristic of these hydrogels is fast gelation behavior after injection. This study describes an all-polysaccharide, rapidly in situ-forming hydrogel composed of carboxymethyl chitosan (CMCHT) and hydroxyethyl cellulose functionalized with aldehyde groups (HEC-Ald). The HEC-Ald was synthesized through acetal functionalization, followed by acid deprotection. This innovative approach avoids cleavage of pyran rings, as is inherent in the periodate oxidation approach, which is the most common method currently employed for adding aldehyde groups to polysaccharides. The resulting hydrogel exhibited fast stress relaxation, self-healing properties, and pH sensitivity, which allowed it to control the release of an encapsulated model drug in response to the medium pH. Based on the collected data, the HEC-Ald/CMCHT hydrogels show promise as pH-sensitive drug carriers.
... The protonated nitrogen (=N + -) peak arises at 400.1 eV [39]. The O 1s spectra have three peaks at 530.7 eV, 531.5 eV, and 532.6 eV corresponding to Fe 2 O 3 , C=O, and C-O bonds, respectively [40]. Using DockThor software, an analysis of molecular docking was performed to predict RCM and SRB protein interactions [41]. ...
The primary goal of this study is to discover a sustainable, renewable, and ecologically friendly anticorrosive inhibitor. Anticorrosion analysis of Capsicum annuum fruit extract (CAFE) was examined under hydrodynamic solution at 1500 rpm in 15 % on P110 steel. Results of the assessment showed that CAFE inhibits the corrosion of P110 steel and the rate of corrosion is significantly reduced on increasing its dosing amount. CAFE exhibits the maximum anticorrosive efficiency to 89.5 % (CAFE/800 mg/L) and 92.2 % (CAFE + KI/600 mg/L). The CAFE shows the chemical nature of inhibition effect. The maximum and minimum charge transfer resistance ( R ct ) and double layer capacitance ( C dl ) are 239.5 Ω cm ⁻¹ and 27 μF/cm ² with the addition of CAFE indicate the corrosion inhibition mitigation. The corrosion mitigation is caused by the adsorption of CAFE molecules on P110 steel surface via Temkin isotherm with chemical mechanism adsorption. The metal surface appearance was visualized via scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). The interaction among the most active constituent i.e., Capsaicin (RCM) sulfate reducing bacteria (SRB) protein was examined by molecular docking. Additionally, an atomic level study of RCM was performed using DFT and MD.
... The inhibiting action is due to the adsorption of molecular and protonated species on the anodic and cathodic sites forming a chemisorbed film on the steel surface. The Polarization studies confirmed that EHEC with/without KI was a mixed-type inhibitor with a predominant cathodic effect [55,56]. ...
... The poly(SA-Tol-BZ) coating, with its crosslinked network, demonstrated superior corrosion resistance ability compared to bare MS. According to Table S1, our poly(SA-Tol-BZ) has the highest inhibition effect among other inhibitors in the same corrosive medium [42][43][44][45][46][47][48][49][50][51][52][53][54][55], suggesting that it is highly effective in inhibiting corrosion and holds great promise for anti-corrosive applications. ...
In this study, we utilized salicylaldehyde (SA) and p-toluidine (Tol-NH2) to synthesize 2-(Z)[(4-methylphenyl)imino]methylphenol (SA-Tol-SF), which was then reduced to 2-[(4-methylphenyl)amino]methylphenol, producing SA-Tol-NH. SA-Tol-NH was further reacted with formaldehyde to create SA-Tol-BZ monomer. Poly(SA-Tol-BZ) was produced by thermally curing it at 210 °C, after synthesizing it from SA-Tol-BZ. The chemical structure of SA-Tol-BZ was analyzed using various analytical techniques such as FT-IR, 1H NMR spectroscopy, and 13C NMR spectroscopy TGA, SEM, DSC, and X-ray analyses. Afterward, we applied the obtained poly(SA-Tol-BZ) onto mild steel (MS) using thermal curing and spray coating techniques. To examine the anticorrosion attributes of MS coated with poly(SA-Tol-BZ), electrochemical characterization was employed. The study proved that poly(SA-Tol-BZ) coating had a high level of effectiveness in preventing corrosion on MS, with an efficacy of 96.52%, and also exhibited hydrophobic properties.
... The poly(SA-Tol-BZ) coating, with its crosslinked network, demonstrated superior corrosion resistance ability compared to bare MS. According to Table S1, our poly(SA-Tol-BZ) has the highest inhibition effect among other inhibitors in the same corrosive medium [42][43][44][45][46][47][48][49][50][51][52][53][54][55], suggesting that it is highly effective in inhibiting corrosion and holds great promise for anti-corrosive applications. ...
In this research, an analysis of the electricity market in Ecuador is carried out, a portfolio of projects by source is presented, which are structured in maps with a view to an energy transition according to the official data provided. State policies are analyzed, as well as the opportunities for development in renewable energies offered by the reform of the Organic Law of the Electric Power Public Service. Additionally, the roadmap is presented, which includes an increase in the levels of renewable energies and a decrease in fossil fuels in consideration of the growing demand for electrical energy with a view to 2050 in accordance with the state approaches defined in recent years. It is considered that the total 100% renewable installed capacity by 2050 is 26,551.18 MW compared to 11,306.26 MW in 2020 between renewable and non-renewable. It is expected that the current legal framework will continue to articulate strategies for a greater penetration of renewable energies, that national purposes be achieved and international agreements celebrated both regionally and globally be fulfilled, so it is important that sufficient resources are allocated to achieve this long-awaited energy transition in Ecuador.
... Different classes of organic compounds have been used as corrosion inhibitors; however, the investigation of natural organic compounds is particularly interesting because of their relatively low cost and because they are considered environmentally safe [15][16][17]. In this context, carbohydrates [18][19][20][21][22][23] and xanthine derivatives such as theophylline [24,25], theobromine [26], and caffeine [14,18,[27][28][29][30][31][32][33] have been used as corrosion inhibitors of metals. ...
A series of novel 1-N-α-d-glucopyranosyl-1H-1,2,3-triazole xanthines was synthesized from azido sugars (glucose, galactose, and lactose) and propargyl xanthines (theophylline and theobromine) using a typical copper (I)-catalyzed azide–alkyne 1,3-dipolar cycloaddition. The corrosion inhibition activities of these new carbohydrate-xanthine compounds were evaluated by studying the corrosion of API 5 L X70 steel in a 1 M HCl medium. The results showed that, at 10 ppm, a 90% inhibition efficiency was reached by electrochemical impedance spectroscopy. The inhibitory efficiency of these molecules is explained by means of quantum chemical calculations of the protonated species with the solvent effect, which seems to better represent the actual situation of the experimental conditions. Some quantum chemical parameters were analyzed to characterize the inhibition performance of the tested molecules.
... HCl interfacial zone. The Log│Z│-LogF plots' slopes approach -1 in the high-frequency regions and all the phase angles obtained are less than 90° for the various expired piroxicam drug concentrations because the interface is capacitive but did not behave as an ideal capacitor [37,38]. Hence justifying the choice and inclusion of a CPE in the circuit. ...
Illegal disposal and recirculation of expired drugs is a global menace which can be solved by their re-utilization as corrosion inhibitors. Thus, helping to combat the current widespread corrosion-induced wastage of expensive mild steel infrastructure. The experimental investigation evaluated the capability and effectiveness of an expired drug (piroxicam) for inhibiting mild steel corrosion in blank 0.5M HCl and acidic environments containing 2 to 8 g/L of the expired drug. Spectrometry, weight loss analysis, atomic absorption spectroscopy, microscopy, polarisation and electrochemical impedance study (EIS) were employed. Analyses revealed drastic inhibition of corrosion in mild steel by expired piroxicam drug in the acid. Corrosion currents () obtained at all concentrations of the expired drug were reduced in comparison to that of the uninhibited environment. The solution resistance recorded was not significantly altered; charge transfer resistances were increased while the capacitance of the electrochemical double layers (Double layer capacitance) as well as the concentration of dissolved iron (Fe n+) ions in the environment, were all reduced with increasing concentration of the expired drug. Although moderate amounts of the expired drug delivered appreciable levels of corrosion inhibition when dissolved directly into the corrosive environment and without any pre-treatment, increased concentration of expired drug resulted in increased corrosion inhibition efficiency. The highest corrosion inhibition efficiency obtained was 97.6% and was from the acidic environment that contained 8 g/L of expired piroxicam drug. The expired piroxicam drug inhibited corrosion of mild steel in 0.5M HCl acid via spontaneous physical adsorption (physisorption) process(s), obeying Langmuir's adsorption isotherm.
... These materials can be synthesized through simple methods from various natural sources with long carbon chains, thus making living organisms safe. The precursors are commonly abundant in natural sources, relatively cheap, and renewable [34]. Meanwhile, doping processes by putting in heteroatoms effectively improve the unique properties of CDs like emission spectrum range, fluorescence phenomenon, corrosion inhibitor, and other features [35][36]. ...
Corrosion is spontaneity and unavoidable reactions which cause degradation in the quality of the materials. Most industries have been harmed by the corrosion of manufacturing equipment. Several methods can be applied to control this problem. The use of corrosion inhibitors is an effective and practical way to decrease metal deterioration significantly. Many commercial inorganic and organic compounds are effective inhibitors, but most of them are not completely safe and relatively expensive. Carbon dots and their derivatives are potential compounds for resolving corrosion reactions on metal surfaces. Carbon dots can be synthesized from various natural sources to be more environmentally friendly. This systematic review aims to summarize the concept of corrosion, types of carbon dots-based corrosion inhibitor and their effectiveness on various metals, inhibition mechanism, surface analysis of the protected metals, kinetics, thermodynamics, and quantum computational chemistry studies. This review also presents the significance and the prospects of carbon dots-based corrosion inhibitors.
... More so, the rate of corrosion also reduces with the increase in time of exposure. Sequentially, the increase in the proportion of PAPE as an inhibitor will enhance the absorption rate of the inhibitor elements on the surface of mild steel that leading to a reduction in corrosion (El Ibrahimi et al., 2020;Olusegun et al., 2018;Alaneme et al., 2015;Arukalam et al., 2015;Eddy et al., 2015;Chakravarthy and Mohana, 2014;Oguize et al., 2015). The Inhibition Efficiency against the time curve at a varying concentration of PAPE in 1M HCL is presented in Fig. 6. ...
This study investigates the influence of Prosopis Africana pod extract (PAPE) on corrosion behavior of mild steel in 1.0 M HCl. The Prosopis African Seed Extract (PASE) was previously characterized as a green corrosion inhibitor without considering its pod, which often constitutes environmental pollution. The PAPE solution was administered in varying concentrations of 0.0 g/ml to 10.0 g/ml as a green inhibitor of mild steel in 1M Hydrochloric (HCl) medium at room temperature using gravimetric, gasometric and electrochemical (Tafel Polarization) techniques. The volume of hydrogen evolution determined with gasometric process decreases as the concentration of the extract increases. The gravimetric technique recorded the highest inhibition efficiency (IE%) of 97.14% with a 1.0g/l concentration of PAPE. The electrochemical measurements of the corrosion current density (ICorr) decreased as the concentration of PAPE increased, with a maximum IE% of 80.59% (PAPE) at 1.0g/l recorded. Generally, IE% increases with the concentration of the extract. The decrease in the corrosion rate is caused by the intensified obstructive mechanism in the coupon surfaces instigated by the pod extract's adsorption. Hence, the extract from Prosopis Africana Pod is equally suitable as a green inhibitor for corrosion.
... In all of these polymers and polymeric systems used as corrosion inhibitors, one thing is remarkable -the adsorption of the molecules for corrosion inhibition is similar. Thus, the corrosion inhibition by polymers and polymeric systems has been reported to be dependent on the adsorbed functional groups such as -OH, -COOH, -NH 2 and others [19,20], or atoms like O, N, S to P [21]. Also, corrosion inhibition by cyclic polymeric inhibitors could be attributed to the presence of aromatic molecules, the effect of electron density of the inhibitor molecules and the nature of a surface charge on the metal. ...
... As a critical criteria, standard Gibbs free energy values of − 20 kJ mol −1 or lower negative values are indicative of electrostatic interaction between both molecules and metal surface that are charged, and this is regarded as physical adsorption [38]. In another consideration, the Gibbs free energy values of − 40 kJ mol −1 or higher negative values encompass charge sharing or transfer from the inhibitor molecules to the substrate surface to form a coordinate covalent bond herein referred to as chemical adsorption [19,39]. Hence, the obtained values of ∆G o ads shown in Table 3 presents increasing negativity suggesting an inclination towards chemical adsorption. ...
Corrosion inhibition effect of aqueous polyethylene glycol (PEG) on cold-rolled steel corrosion in 1.0 M HCl solution was studied using weight loss, electrochemical potentiodynamic polarization, quantum chemical computation, molecular dynamics simulation, and scanning electron microscopy (SEM) analytical techniques. The effect of immersion time, inhibitor concentration and temperature on the corrosion behaviour of cold-rolled steel in 1.0 M HCl was studied. The results revealed that PEG satisfactorily inhibited corrosion of cold-rolled steel in the acid solution by adsorption of its molecules on the metal surface, decreasing both the anodic and cathodic reactions. Temperature studies showed that inhibition efficiency increased with rise in temperature from 303 – 343 K. Quantum chemical calculations conducted using density functional theory (DFT) showed values of EHOMO, ELUMO and energy gap for PEG to be − 7.2219 eV, − 0.3958 eV and 6.8261 eV, respectively, and thus confirmed the interaction between the PEG inhibitor molecules and the metal surface. Furthermore, the computed values of Fukui indices indicated that O(7) atom in the PEG molecule was most susceptible to nucleophilic attacks, while the O(10) atom was well disposed for electrophilic reactions. The negative values of interaction energy obtained by molecular dynamics simulation, -107.7898 kcal/mol and -109.5136 kcal/mol at 303 K and 343 K, respectively, confirmed that PEG-metal interaction was good. SEM was used to confirm the adsorption of PEG on the surface of cold-rolled steel. Based on the analyses conducted, the inhibitive mechanism for corrosion of cold-rolled steel in 1.0 M HCl solution has been established.
