Bio-/Environment-Friendly Cationic Gemini Surfactant as Novel Corrosion Inhibitor for Mild Steel in 1 M HCl Solution

Synthesis of Gemini-type imidazoline quaternary ammonium salt using by-product fatty acid as corrosion inhibitor for Q235 steel

Gemini-type imidazoline quaternary ammonium salt is a new type of environmentally friendly corrosion inhibitor has been widely used in engineering materials. However, most of them are hazardous/toxic compounds derived from petroleum-based products, which did harm to environment. In this work, an environmentally friendly Gemini-shaped imidazoline quaternary ammonium salt corrosion inhibitor (G211) was synthesized using cheap fatty acid recycled from dimer acid industry as feedstock. The corrosion inhibition effects of G211 on Q235 steel in 1 M HCl solution were investigated through weight loss experiments, potential polarization curves, and alternating current impedance spectroscopy experiments. The results show that the inhibition rate of G211 as a mixed-type inhibitor is up to 94.4% and the concentration drop as low as 500 ppm at 25 ℃. The adsorption of G211 on Q235 surface follows Langmuir adsorption isothermal curve. The chemical composition of the Q235 steel surface was analyzed through scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Furthermore, the possible corrosion inhibition mechanism of G211 on the surface of Q235 steel is proposed. This article not only presents an outstanding solution for safeguarding Q235 steel against corrosion but also introduces a feasible method for high-value utilization of monomer acid (MA).

Application of Biomass Corrosion Inhibitors in Metal Corrosion Control: A Review

Corrosion is the process of damaging materials, and corrosion of metallic materials frequently results in serious consequences. The addition of corrosion inhibitors is the most effective means of preventing metal corrosion. Until now, researchers have made unremitting efforts in the research of high-efficiency green corrosion inhibitors, and research on biomass corrosion inhibitors in a class of environmentally friendly corrosion inhibitors is currently quite promising. This work presents the classification of green biomass corrosion inhibitors in detail, including plant-based corrosion inhibitors, amino acid corrosion inhibitors, and biosurfactant corrosion inhibitors, based on the advantages of easy preparation, environmental friendliness, high corrosion inhibition efficiency, and a wide application range of biomass corrosion inhibitors. This work also introduces the preparation methods of biomass corrosion inhibitors, including hydrolysis, enzymatic digestion, the heating reflux method, and microwave extraction. In addition, the corrosion inhibition mechanisms of green biomass corrosion inhibitors, including physical adsorption, chemisorption, and film-forming adsorption, and evaluation methods of biomass corrosion inhibitors are also explicitly described. This study provides valuable insights into the development of green corrosion inhibitors.

Novel ZrO2-glycine nanocomposite as eco-friendly high temperature corrosion inhibitor for mild steel in hydrochloric acid solution

We report the green synthesis of novel ZrO₂-Glycine nanocomposite referred to as ZrO₂-Gly NC followed by its characterization using X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) spectroscopy, SEM/EDX, and transmission electron microscopy (TEM) techniques. Further, the inhibition effect of the varying concentration of ZrO₂-Gly NC on the corrosion of mild steel (MS) in 1 M HCl was investigated by weight loss and electrochemical measurements at 40-80 °C. The percentage inhibition efficacy of NC increased with the increase of concentration and temperature and reached about 81.01% at 500 ppm at 70 °C which decreased at 80 °C and exhibited 73.5% inhibition efficiencies. According to the polarization measurements, the investigated ZrO₂-Gly NC works as a mixed-type inhibitor with predominantly inhibiting cathodic reaction. Also, the adsorption isotherm analysis indicated that the adsorption was spontaneous and followed the Langmuir adsorption isotherm. Furthermore, the contact angle measurement revealed the water-repelling property of the investigated inhibitor. The surface morphological study via SEM-EDS micrograph affirmed the appearance of a smooth surface in presence of inhibited media suggesting the formation of protective film by the adsorption of ZrO₂-Gly NC on the surface of the MS even at higher temperature.

Protoporphyrin Extracted from Biomass Waste as Sustainable Corrosion Inhibitors of T22 Carbon Steel in Acidic Environments

Carbon steel is one of the most employed materials in many industrial sectors due to its unique physical and mechanical properties. However, within a certain period of time, carbon steel-based materials are susceptible to corrosion under operating conditions and corrosion inhibitors are important to extending the limit of use of carbon steel. In this study, the influence of protoporphyrin from animal blood hemin as an eco-friendly corrosion inhibitor for T22 carbon steel in an acidic environment (0.5 M HCl) was conducted. The hemin isolated from animal blood extracts was modified to obtain the protoporphyrin. The dosage of protoporphyrin was varied between 40 and 200 ppm and the temperature influence were studied in the range of 298–318 K. The inhibition efficiency of protoporphyrin in 0.5 M hydrochloric acid reached up to 46.2% at a dose of 160 ppm at a temperature of 298 K. The inhibition efficiency (IE) value further decreases with increasing temperature, thereby showing the process exothermic in nature and the weakening of the inhibitor molecules to adsorb on the surface of the T22 carbon steel. The potentiodynamic polarization measurements indicate that protoporphyrin acts as a mixed-type inhibitor. The adsorption of protoporphyrin on the surface of T22 carbon steel obeys the Langmuir adsorption isotherm. The thermodynamic parameter of adsorption allows us to suggest the adsorption process was dominated by physical adsorption. Thus, these current results present a case study using protoporphyrin as a promising green inhibitor for carbon steel T22 in hydrochloric acid prepared from livestock waste.

Application of surfactants as anticorrosive materials: A comprehensive review

Corrosion is the degradation of a metal due to its reaction with the environment. One of the most efficient ways of securing metal surfaces from corrosion is the use of corrosion inhibitors. Their efficacy is connected to their chemical composition, their molecular structures, and their adsorption affinities on the metal surface. This review article focuses on the prospects of different types of monomeric and gemini surfactants, mixed surfactants systems, surfactants- additives mixed systems, inhibitors-surfactants (as additives) mixed systems, and ionic liquid based surfactants as promising corrosion-inhibiting formulations in the aqueous phase and the role of surfactants in developing protective coatings. The analysis starts with an accurate overview of the characteristics, types, and structure-property-performance relationship of anti-corrosion formulations of such inhibitors.

Recent advances on micellar catalysis in water

Water is the universal solvent in nature to catalyze the biological transformation processes. However, owing to the immiscibility of many reagents in water, synthesis chemistry relies heavily on organic solvent. Micellar media is a green alternative to traditional petroleum feedstock derived solvents, which is recently attracting increasing research attention. The present review deals with the recent advances in micellar catalysis with an emphasis on the new "tailor-made" surfactants for various reactions. A brief overview of commercial surfactants, including anionic micelles, cationic micelles, and nonionic micelles is presented. More importantly, an attempt was made to discuss systematically the recent research progress on new surfactants by introducing structures, micellar effects and recycling process, aiming to serve as the basis for future development of surfactants.

AEO7 Surfactant as an Eco-Friendly Corrosion Inhibitor for Carbon Steel in HCl solution

The impact of AEO7 surfactant on the corrosion inhibition of carbon steel (C-steel) in 0.5 M HCl solution at temperatures between 20 °C and 50 °C was elucidated using weight loss and different electrochemical techniques. The kinetics and thermodynamic parameters of the corrosion and inhibition processes were reported. The corrosion inhibition efficiency (IE%) improved as the concentration of AEO7 increased. In addition, a synergistic effect was observed when a concentration of 1 × 10⁻³ mol L⁻¹ or higher of potassium iodide (KI) was added to 40 µmol L⁻¹ of the AEO7 inhibitor where the corrosion IE% increased from 87.4% to 99.2%. Also, it was found that the adsorption of AEO7 surfactant on C-steel surface followed the Freundlich isotherm. Furthermore, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements indicated that AEO7 was physically adsorbed on the steel surface. The surface topography was examined using an optical profilometer, an atomic force microscope (AFM), and a scanning electron-microscope (SEM) coupled with an energy dispersion X-ray (EDX) unit. Quantum chemical calculations based on the density functional theory were performed to understand the relationship between the corrosion IE% and the molecular structure of the AEO7 molecule.

Development, Characterization and Electromechanical Actuation Behavior of Ionic Polymer Metal Composite Actuator based on Sulfonated Poly(1,4-phenylene ether-ether-sulfone)/Carbon Nanotubes

This paper presents the development of new cost-effective hybrid-type sulfonated poly(1,4-phenylene ether-ether-sulfone) (SPEES) and functionalized single-walled carbon nanotubes (SWNT) based actuators produced by the film-casting method followed by chemical reduction of Pt ions as electrodes. The preparation of SPEES was investigated in details and sulfonation of polymer was characterized by ion exchange capacity (IEC), Fourier-transform infrared (FTIR) and degree of sulfonation measurements. SPEES having degree of sulfonation of 126% was blended with SWNT and used to fabricate IPMC actuator. The chemical composition and detailed structure of SPEES-SWNT ionic polymer membranes were confirmed by FTIR, EDX and transmittance electron microscopy (TEM) analysis. Scanning electron microscopy (SEM) micrographs revealed the homogeneously distributed layers of Pt electrodes on the surfaces of IPMC membrane. The electrochemical and electromechanical properties of SPEES-SWNT-Pt-based IPMC actuator shows a better actuation performance than conventional IPMC actuators in terms of higher IEC, Proton conductivity, higher current density, electrochemical impedance spectroscopy (EIS), and large bending deflection. The robust, flexible and mechanically strong membranes prepared by the synergistic combination of SPEES and SWNT may have considerable potential as actuator materials for robotic and biomimetic applications.

L-proline mixed with sodium benzoate as sustainable inhibitor for mild steel corrosion in 1M HCl: An experimental and theoretical approach

Following standard experimental (gravimetric measurements, potentiodynamic polarization measurements, electrochemical impedance measurements, spectroscopic measurements, scanning electron microscopy technique) and theoretical (DFT) approach, inhibition effect of L-proline (LPr) and LPr mixed with sodium benzoate (LPr + NaBenz) for mild steel (MS) corrosion in 1M HCl was studied at 30, 40, 50 and 60 °C. The concentration of LPr was varied between 100-600 ppm, whereas that of NaBenz was fixed at 10 ppm. LPr lowered the corrosion rates of MS to a considerable extent. Corrosion mitigating efficacy of LPr is synergistically enhanced on adding NaBenz at all concentrations. Evaluation of polarization parameters suggested that both LPr and LPr + NaBenz act as mixed type inhibitor with more control on cathodic reaction whereas impedance parameters suggested inhibition of metal corrosion by adsorption at the MS/solution interface. Surface microscopic examination of corroded and uncorroded MS coupons supported the protective effect of adsorbed inhibitor layer at the MS surface. Spectroscopic studies are suggestive of the complex formation between inhibitor molecules and the metal. When LPr is combined with NaBenz, the corrosion inhibition rate was improved greatly. Corrosion mitigating efficacy of LPr or LPr mixed with NaBenz obtained by different techniques are in good agreement and correlate well with theoretical quantum chemical descriptors.

Sugar based N,N'-didodecyl-N,N'digluconamideethylenediamine gemini surfactant as corrosion inhibitor for mild steel in 3.5% NaCl solution-effect of synergistic KI additive

The inhibitory behaviour of non-ionic sugar based N,N'-didodecyl-N,N'-digluconamideethylenediamine gemini surfactant, designated as Glu(12)-2-Glu(12) on mild steel (MS) corrosion in 3.5% NaCl at 30-60 °C was explored using weight loss, PDP, EIS and SEM/EDAX/AFM techniques. The compound inhibited the corrosion of mild steel in 3.5% NaCl and the extent of inhibition was dependent on concentration and temperature. The inhibiting action of Glu(12)-2-Glu(12) is synergistically enhanced on addition of potassium iodide (KI) at all concentrations and temperatures. The inhibiting formulation comprising of 2.5 × 10-3 mM of Glu(12)-2-Glu(12) and 10 mM of KI exhibits an inhibition efficiency of 96.9% at 60 °C. Quantum chemical calculations and MD simulation were applied to analyze the experimental data and elucidate the adsorption behaviour and inhibition mechanism of inhibitors. MD simulation showed a nearly parallel or flat disposition for Glu(12)-2-Glu(12) molecules on the MS surface providing larger blocking area to prevent the metal surface from corrosion.

Ester-Based Pyridinium Gemini Surfactants as Novel Inhibitors for Mild Steel Corrosion in 1 M HCl Solution

The corrosion inhibition ability of ester based pyridinium Gemini surfactants (GS) with different hydrophobic character (14-Py and 16-Py) towards mild steel (MS) in 1 M HCl solution was investigated at various concentrations and temperatures (303–333 K). Potentiodynamic polarization, electrochemical impedance spectroscopy, weight loss, surface analysis (SEM/EDAX and AFM) and FT-IR were combined to investigate the corrosion inhibition behaviour of the surfactants. 14-Py and 16-Py were found to be efficient, mixed type inhibitors. The inhibition efficiencies increased with increasing concentration, hydrophobicity and solution temperature. The existence of a protective film of the adsorbed inhibitors on the MS surface was confirmed by SEM/EDX/AFM.

Synthesis, Structure, Surface and Antimicrobial Properties of New Oligomeric Quaternary Ammonium Salts with Aromatic Spacers

New dimeric, trimeric and tetrameric quaternary ammonium salts were accomplished by reaction of tertiary alkyldimethyl amines with appropriate bromomethylbenzene derivatives. A series of new cationic surfactants contain different alkyl chain lengths (C4-C18), aromatic spacers and different numbers of quaternary nitrogen atoms. The structure of the products was confirmed by spectral analysis (FT-IR, ¹H-NMR, ¹³C-NMR and 2D-NMR), mass spectroscopy (ESI-MS), elemental analysis, as well as PM5 semiempirical methods. Compound (21) was also analyzed using X-ray crystallography. Critical micelle concentration (CMC) of 1,4-bis-[N-(1-alkyl)-N,N-dimethylammoniummethyl]benzene dibromides (3-9) was determined to characterize the aggregation behavior. The antimicrobial properties of novel QACs (Quaternary Ammonium Salts) were examined to set their minimal inhibitory concentration (MIC) values against fungi Aspergillus niger, Candida albicans, Penicillium chrysogenum and bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa.

N,N'-Dialkylcystine Gemini and Monomeric N-Alkyl Cysteine Surfactants as Corrosion Inhibitors on Mild Steel Corrosion in 1 M HCl Solution: A Comparative Study

Gemini surfactant, N,N'-dialkylcystine 2(C₁₂Cys), derived from cystine, and a monomeric N-alkyl cysteine counterpart, (C₁₂Cys), were synthesized and purified. The characterization of surfactants 2(C₁₂Cys) and (C₁₂Cys) was made by Fourier transform infrared, ¹H NMR, and elemental analysis. The effect of 2(C₁₂Cys) and (C₁₂Cys) on mild steel (MS) corrosion in 1 M HCl solution was explored as a function of their concentration and electrolyte temperature by means of gravimetric and electrochemical experiments (potentiodynamic polarization and Electrochemical impedance spectroscopy), surface analytical techniques (scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDAX) and atomic force microscopy (AFM)) and theoretical study. The investigated compounds exhibited surface active properties and performed as good inhibitors for corrosion control of mild steel (MS) in acid solution. However, compared to monomeric (C₁₂Cys), Gemini surfactant 2(C₁₂Cys) showed high corrosion inhibiting ability at very low concentration. The EIS results revealed a greater charge transfer resistance in 2(C₁₂Cys) solution compared to that in (C₁₂Cys) solution. SEM/EDAX observations validate the development of an inhibitive film by the adsorbed molecules of surfactant on the MS surface. The AFM micrographs supported the SEM/EDAX results and exhibited a lowering in the roughness of the corroded MS surface in the presence of both (C₁₂Cys) and 2(C₁₂Cys) surfactants. Further, quantum chemical calculations and Monte Carlo simulations were used to study the dependence of corrosion inhibiting efficacy on the molecular structure and adsorption strength.