Organic Corrosion Inhibitors

Organic corrosion inhibitors are one of the five ways, besides material selection, design, cathodic protection and coatings, to protect materials against corrosion. Corrosion is an ubiquitous phenomena that deteriorates all materials, metals, plastics, glass and concrete. The costs of corrosion are tremendous and amounts to 4.0% of gross domestic product (GDP) in USA. The similar losses of GDP are noted in all countries around the world. At this point of time, there is no way to completely stop the corrosion processes. Some new solutions can only slow this process. Organic corrosion inhibitors are widely used in industry because of their effectiveness at wide range of temperatures, compatibility with protected materials, good solubility in water, low costs and relatively low toxicity. Organic corrosion inhibitors adsorb on the surface to form protective film which displace water and protect it against deteriorating. Effective organic corrosion inhibitors contain nitrogen, oxygen, sulfur and phosphorus with lone electron pairs as well can contain structural moieties with π-electrons that interact with metal favoring the adsorption process. This review presents mechanisms and monitoring of corrosion, laboratory methods for corrosion study, relationship between structure and efficacy of corrosion inhibitions, theoretical approach to design new inhibitors and some aspects of biocorrosion

Triethylphosphite as a network forming agent enhances in-vitro biocompatibility and corrosion protection of hybrid organic-inorganic sol-gel coatings for Ti6Al4V alloys

The biocompatibility and life of metallic implants can be enhanced through improving the biocompatibility and corrosion protection characteristics of the coatings used with these materials. In this study, triethylphosphite (TEP) was used to introduce phosphorus into organic-inorganic hybrid silica based sol gel coatings prepared using γ-methacryloxypropyltrimethoxysilane and tetramethylorthosilicate. Addition of TEP dramatically increased the rate of intermolecular condensation and resulted in materials showing greater cross linking. Protein (fibrinogen) uptake, osteoblast in vitro biocompatibility and corrosion resistance was enhanced in coatings containing TEP. Although higher concentrations of phosphorus supported the greatest improvement in biocompatibility, a compromise in the phosphorus concentration used would be required if corrosion resistance was most desirable parameter for optimisation. Films prepared by dip coating on Ti6Al4V alloys from these sols offer a promising alternative to wholly metallic prostheses

Anode materials for electrochemical waste destruction

Electrochemical Oxidation (ECO) offers promise as a low-temperature, atmospheric pressure method for safe destruction of hazardous organic chemical wastes in water. Anode materials tend to suffer corrosion in the intensely oxidizing environment of the ECO cell. There is a need for cheaper, more resistant materials. In this experiment, a system is described for testing anode materials, with examples of several common anodes such as stainless steel, graphite, and platinized titanium. The ECO system is simple and safe to operate and the experiment can easily be expanded in scope to study the effects of different solutions, temperatures, and organic materials

Quantum chemical study of heterocyclic organic compounds on the corrosion inhibition

Corrosion damages all materials, necessitating replacement and inspection related expenses. Thus, the demand has increased for new corrosion inhibitor materials. The ratios of corrosion inhibition of materials are different, but organic compounds have high efficiency in aqueous corrosion inhibition for various alloys and metals. This efficiency can increase in the presence of O, N and S. The molecule provides great inhibition with the presence of both S and N atoms in the same compound. This paper investigates the 1, 3, 4-thiadiazole molecule and electronic structure of several organic compounds such as R1 and R2 which consist of different substituent groups. They were united to the ring of 1, 3, 4-thiadiazole to provide nine different derivatives. Quantum computations (density functional theory, DFT) at 6-311G++ (d, p) basis set and Becke’s three parameters hybrid (B3LYP) level were performed using Gaussian program. The purpose of this study is to determine the chemical behaviour of several heterocyclic organic compounds and to understand the process of the corrosion inhibition

Metal evaporated tape: state of the art and prospects

Thin metallic films are the first choice for media in advanced rigid disk systems. For helical scan tape recorders thin metal films have become more important. The high signal-to-noise ratio per unit of track width allows very high densities. The preparation techniques and materials properties of the thin-film coating of metal evaporated (ME) are described. Important aspects are the size of the grains, the geometry of the columnar structure and the associated anisotropy. The consequences for the recording process are explained. Tribological and corrosion properties also help to determine the usefulness of a recording tape. Corrosion, wear, protection layers and lubricating organic films are briefly discussed

Inorganic materials in industrial processes

Although inorganic materials represent a small number to the extreme number of the organic ones, they play a number of crucial roles in several processes of industrial interest. Two significant technologically processes have been selected as “case studies” for this presentation: metallic corrosion and its control, and mitigation of inorganic deposits, both related to industrial water systems.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Current developments of nanoscale insight into corrosion protection by passive oxide films

Oxide passive films are a key for the durability of metals and alloys components as well as a central issue in corrosion science and engineering. Herein, we discuss current developments of the nanometer and sub-nanometer scale knowledge of the barrier properties and adsorption properties of passive oxide films brought by recent model experimental and theoretical investigations. The discussed aspects include (i) the chromium enrichment and its homogeneity at the nanoscale in passive films formed on Cr-bearing alloys such as stainless steel, (ii) the corrosion properties of grain boundaries in early intergranular corrosion before penetration and propagation in the grain boundary network, and (iii) the interaction of organic inhibitor molecules with incompletely passivated metallic surfaces. In all three cases, key issues are highlighted and future developments that we consider as most relevant are identified.Comment: Current Opinion in Solid State and Materials Science, Elsevier, final accepted preprin

Green Inhibitors for Prevention of Metal and Alloys Corrosion: An Overview

Corrosion control of metal is of technical, economical, environmental and aesthetical importance. The use of inhibitor is the best way to prevent metal and alloys from corrosion. There is an intensive effort underway to develop new plant origin corrosion inhibitors for metal subjected to various environmental conditions. These efforts are motivated by the desire to replace toxic organic corrosion inhibitors used for mitigation of corrosion of various metals and alloys in solutions. Plants represent a class of interesting source of compounds currently being explored for use in metal corrosion protection in most systems, as possible replacement of toxic synthetic inhibitors. The green corrosion inhibitors are bio degradable, non-toxic, environmentally benign, and low cost, are obtained from renewable resources with minimal health and safety concerns. Investigations of corrosion inhibiting abilities of tannins, alkaloids, organic amino acids and organic dyes of plant origin are of interest. Development of computational modeling backed by wet results would help in understanding the mechanism of inhibition action, their adsorption patterns, inhibitor-metal surface interface and help in the development of designer inhibitor with an understanding of the time required for the release of self-healing inhibitors. The present paper restricts itself mainly to the plant materials as “Green Corrosion Inhibitor”. Keywords: Green Corrosion Inhibitor, Corrosion Inhibition, Plant Extracts

Advances in Organic Corrosion Inhibitors and Protective Coatings

The interaction of metal with its environment that results in its chemical alteration is called metallic corrosion. According to the literature, corrosion is classified to two types: uniform and localized corrosion. Intervention in either in the alloy environment or in the alloy structure can provide the corrosion protection of metallic materials. Furthermore, the interference in the metal alloy environment can be conducted with the utilization of cathodic or anodic protection via the corresponding inhibitors. Therefore, the most common categorization is cathodic, anodic, and mixed-type inhibitors, taking into account which half-reaction they suppress during corrosion phenomena. The majority of the organic inhibitors are of mixed type and perform through chemisorption. In order to update the field of the corrosion protection of metal and metal alloys with the use of organic inhibitors, a Special Issue entitled "Advances in Organic Corrosion Inhibitors and Protective Coatings" is introduced. This book gathers and reviews a collection of ten contributions (nine articles and one review), from authors from Europe, Asia, and Africa, that were accepted for publication in this Special Issue of Applied Sciences

Layered double hydroxides for corrosion-related applications: main developments from 20 years of research at CICECO

This work describes the main advances carried out in the field of corrosion protection using layered double hydroxides (LDH), both as additive/pigmentbased systems in organic coatings and as conversion films/pre-treatments. In the context of the research topic “Celebrating 20 years of CICECO”, the main works reported herein are based on SECOP’s group (CICECO) main advances over the years. More specifically, this review describes structure and properties of LDH, delving into the corrosion field with description of pioneering works, use of LDH as additives to organic coatings, conversion layers, application in reinforced concrete and corrosion detection, and environmental impact of these materials. Moreover, the use of computational tools for the design of LDH materials and understanding of ion-exchange reactions is also presented. The review ends with a critical analysis of the field and future perspectives on the use of LDH for corrosion protection. From the work carried out LDH seem very tenable, versatile, and advantageous for corrosion protection applications, although several obstacles will have to be overcome before their use become commonplace.publishe