Chitosan based new nanocomposites for corrosion protection of mild steel in aggressive chloride media

Eco-friendly anti-corrosion performance of chitosan modified with fused heterocyclic compound on mild steel in acidic medium

This study aims to explore the prevention of chitosan modified with a fused heterocyclic compound as a sustainable corrosion inhibitor for mild steel in 1 M HCl. Electrochemical instruments, including potentiodynamic polarization techniques, and electrochemical impedance spectroscopy (EIS), were employed to evaluate the corrosion protection performance. The outcomes showed that the chitosan modified with a fused heterocyclic compound has outstanding inhibition performance, with an inhibition effectiveness of 98.25 % at 100 ppm. The anti-corrosion features of modified chitosan were ascribed to the presence of hetero atoms in modified chitosan composite which leads to the creation of a protective layer, The modified chitosan composite behaved as mixed-typed inhibitors, as shown by the PDP results. The modified chitosan composite adsorbs on mild steel in the investigated corrosive media via chemisorption interactions, and its adsorption followed the Langmuir adsorption model. Furthermore, increasing the temperature from 303 to 333 K enhanced the corrosion rate, most likely due to the desorption of the inhibitor agent from the steel surface.

An appraisal of the utilization of natural gums as corrosion inhibitors: Prospects, challenges, and future perspectives

Natural gums are macro compounds containing monosaccharide (sugar) units bonded by glycosidic to form long polymeric sugar chains of considerably high molecular weight. Natural gums are multifaceted in applications with the main areas being the food and pharmaceutical industries. The recent research interest in corrosion inhibitors is considering natural gums because of their abundance and ecological compatibility. Hence, this review takes a look at the use of natural gums in pure and modified forms in metals protection. The review establishes that the corrosion-protecting ability of natural gums has a direct connotation with their macromolecular weights, chemical composition, and molecular and electronic structures. Immersion duration and temperature are other factors found to affect the inhibition performance of natural gums considerably. The inhibition of natural gums in pure form is found not to be excellent due to their high hydration rate, algal and microbial contamination, solubility that depends on pH, and thermal instability. Common modification techniques adopted by corrosion inhibitor scientists are copolymerization, mixing with chemicals to induce synergism, crosslinking, and insertion of inorganic nanomaterials into the polymer matrix. Infusion of biosynthesized nanoparticles approach towards enhancing the corrosion inhibition efficiency of natural gums is recommended for future studies because of the unique characteristics of nanoparticles.

Heteropolysaccharides in sustainable corrosion inhibition: 4E (Energy, Economy, Ecology, and Effectivity) dimensions

Carbohydrate polymers (polysaccharides) and their derivatives are widely utilized in sustainable corrosion inhibition (SCI) because of their various fascinating properties including multiple adsorption sites, high solubility and high efficiency. Contrary to traditional synthetic polymer-based corrosion inhibitors, polysaccharides are related to the 4E dimension, which stands for Energy, Economy, Ecology, and Effectivity. Furthermore, they are relatively more environmentally benign, biodegradable, and non-bioaccumulative. The current review describes the SCI features of various heteropolysaccharides, including gum Arabic (GA), glycosaminoglycans (chondroitin-4-sulfate (CS), hyaluronic acid (HA), heparin, etc.), pectin, alginates, and agar for the first time. They demonstrate impressive anticorrosive activity for different metals and alloys in a variety of corrosive electrolytes. Through their adsorption at the metal/electrolyte interface, heteropolysaccharides function by producing a corrosion-protective film. In general, their adsorption follows the Langmuir isotherm model. In their molecular structures, heteropolysaccharides contain several polar functional groups like -OH, -NH₂, -COCH₃, -CH₂OH, cyclic and bridging O, -CH₂SO₃H, -SO₃OH, -COOH, -NHCOCH₃, -OHOR, etc. that serve as adsorption centers when they bind to metallic surfaces.

Chitosan based titanium and iron oxide hybrid bio-polymeric nanocomposites as potential corrosion inhibitor for mild steel in acidic medium

Biopolymer chitosan (CS), chitosan grafted acrylamide based titanium dioxide (CS-g-PAM/TiO₂) and magnetite (CS-g-PAM/Fe₃O₄) hybrid nanocomposites have been synthesized through free radical graft co-polymerization and successfully validated as corrosion inhibitors for mild steel in 15 % HCl solution. The synthesized compounds have been characterized through FTIR, APC, XRD and TEM. The thermal stability of the nanocomposites was established by TGA. The anticorrosive performance was determined through gravimetric measurements and by electrochemical study. According to EIS technique it was observed that CS-g-PAM/TiO₂ and CS-g-PAM/Fe₃O₄ showed maximum 97.19 % and 95.49 % efficiency respectively. Langmuir adsorption isotherm is obeyed in each case. The activation and adsorption parameters have been determined from isotherm study. FESEM and AFM confirmed better adsorption layer formed by composites over mild steel surface. The elemental composition of the metal samples was proved by the XPS investigation. DFT and ANOVA test further corroborates the experimental results.

Corrosion Inhibition Evaluation of Chitosan–CuO Nanocomposite for Carbon Steel in 5% HCl Solution and Effect of KI Addition

Chitosan–copper oxide (CHT–CuO) nanocomposite was made by an in-situ method utilizing olive leaf extract (OLE) as reductant. The OLE mediated CHT–CuO nanocomposite containing varying amount of chitosan (0.5, 1.0 and 2.0 g) was evaluated as corrosion inhibitor for X60 carbon steel in 5 wt% hydrochloric acid solution. The corrosion inhibitive performance was assessed utilizing weight loss and electrochemical impedance spectroscopy, linear polarization resistance and potentiodynamic polarization techniques complemented with surface assessment of the corroded X60 carbon steel without and with the additives using scanning electron microscopy/energy dispersive X-ray spectroscopy and 3D optical profilometer. The effect of KI addition on the corrosion protection capacity of the nanocomposites was also examined. Corrosion inhibitive effect was observed to increase with increase in the nanocomposites dosage with the highest inhibition efficiency (IE) achieved at the optimum dosage of 0.5%. The order of corrosion inhibition performance followed the trend CHT1.0–CuO (90.35%) > CHT0.5–CuO (90.16%) > CHT2.0–CuO (89.52%) nanocomposite from impedance measurements. Also, IE was found to increase as the temperature was raised from 25 to 40 °C and afterwards a decline in IE was observed with further increase in temperature to 50 and 60 °C. The potentiodynamic polarization results suggest that the nanocomposites alone and in combination with KI inhibited the corrosion of X60 carbon steel by an active site blocking mechanism. Addition of KI upgrades the IE of the nanocomposites but is not attributable to synergistic influence. The lack of synergistic influence was confirmed from the computed synergism parameter (S1) which was found to be less than unity with values of 0.89, 0.74 and 0.75 for CHT0.5–CuO, CHT1.0–CuO and CHT2.0–CuO nanocomposites, respectively, at 60 °C. Furthermore, KI addition improved the IE with rise in temperature from 25 to 60 °C. Surface analysis results confirm the formation of a protective film which could be attributed to the adsorption of the nanocomposites on the carbon steel surface.

Organic Compounds as Corrosion Inhibitors for Carbon Steel in HCl Solution: A Comprehensive Review

Most studies on the corrosion inhibition performance of organic molecules and (nano)materials were conducted within "carbon steel/1.0 M HCl" solution system using similar experimental and theoretical methods. As such, the numerous research findings in this system are sufficient to conduct comparative studies to select the best-suited inhibitor type that generally refers to a type of inhibitor with low concentration/high inhibition efficiency, nontoxic properties, and a simple and cost-economic synthesis process. Before data collection, to help readers have a clear understanding of some crucial elements for the evaluation of corrosion inhibition performance, we introduced the mainstay of corrosion inhibitors studies involved, including the corrosion and inhibition mechanism of carbon steel/HCl solution systems, evaluation methods of corrosion inhibition efficiency, adsorption isotherm models, adsorption thermodynamic parameters QC calculations, MD/MC simulations, and the main characterization techniques used. In the classification and statistical analysis section, organic compounds or (nano)materials as corrosion inhibitors were classified into six types according to their molecular structural characteristics, molecular size, and compound source, including drug molecules, ionic liquids, surfactants, plant extracts, polymers, and polymeric nanoparticles. We outlined the important conclusions obtained from recent literature and listed the evaluation methods, characterization techniques, and contrastable experimental data of these types of inhibitors when used for carbon steel corrosion in 1.0 M HCl solution. Finally, statistical analysis was only performed based on these data from carbon steel/1.0 M HCl solution system, from which some conclusions can contribute to reducing the workload of the acquisition of useful information and provide some reference directions for the development of new corrosion inhibitors.

Chitosan as a matrix of nanocomposites: A review on nanostructures, processes, properties, and applications

Chitosan is a biopolymer that is natural, biodegradable, and relatively low price. Chitosan has been attracting interest as a matrix of nanocomposites due to new properties for various applications. This study presents a comprehensive overview of common and recent advances using chitosan as a nanocomposite matrix. The focus is to present alternative processes to produce embedded or coated nanoparticles, and the shaping techniques that have been employed (3D printing, electrospinning), as well as the nanocomposites emerging applications in medicine, tissue engineering, wastewater treatment, corrosion inhibition, among others. There are several reviews about single chitosan material and derivatives for diverse applications. However, there is not a study that focuses on chitosan as a nanocomposite matrix, explaining the possibility of nanomaterial additions, the interaction of the attached species, and the applications possibility following the techniques to combine chitosan with nanostructures. Finally, future directions are presented for expanding the applications of chitosan nanocomposites.

A review on chitosan and chitosan-based bionanocomposites: Promising material for combatting global issues and its applications

Over the last few years, several attempts have been made to replace petrochemical products with renewable and biodegradable components. The most challenging part of this approach is to obtain bio-based materials with properties and functions equivalent to those of synthetic products. Various naturally occurring polymers such as starch, collagen, alginate, cellulose, and chitin represent attractive candidates as they could reduce dependence on synthetic products and consequently positively impact the environment. Chitosan is also a unique bio-based polymer with excellent intrinsic properties. It is known for its anti-bacterial and film-forming properties, has high mechanical strength and good thermal stability. Nanotechnology has also applied chitosan-based materials in its most recent achievements. Therefore, numerous chitosan-based bionanocomposites with improved physical and chemical characteristics have been developed in an eco-friendly and cost-effective approach. This review discusses various sources of chitosan, its properties and methods of modification. Also, this work focuses on diverse preparation techniques of chitosan-based bionanocomposites and their emerging application in various sectors. Additionally, this review sheds light on future research scope with some drawbacks and challenges to motivate the researchers for future outstanding research works.