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304 SS substrates have been covered with polymeric class low melting barriers, like polyurethane, acrylate and epoxy with and without incorporation of eco‐friendly (non‐toxic) ceramic particular of antifouling origin. The results of corrosion resistance tests are encouraging. Other physical parameters like hardness, adhesion, scratch resistance are also studied, for these synergistically organized low melting point barrier layers.

The most economical way of protecting pipelines is through the application of organic coatings and wrappings. To make the protection foolproof at holidays and pores, cathodic protection is also applied. At coating holidays, the pipelines act as the cathode generating hydroxyl ion and hydrogen electrochemically. Extensive studies have been carried out using samples of mild steel pipe coated with reinforced coal tar enamel coating to investigate the role of hydrogen and hydroxyl ion on cathodic disbondment. The testing material is subjected to different environmental conditions like pH, aeration and addition of different anionic species. A mechanism has been proposed to describe the individual role of hydroxyl ion and hydrogen in the process of disbondment.

Aluminium alloys are being employed very widely as galvanic anodes for cathodic protection. Aluminium‐zinc‐mercury and aluminium‐zinc‐indium are the popular alloys that are used as anodes. In general, the alloying ingredients activate aluminium and maintain uniform dissolution. In the present investigation, the role of addition of gallium in the ternary alloy of aluminium‐zinc‐indium has been studied by making use of polarisation studies, capacity measurements and galvanic current measurements.

The efficacy of antiscaling treatments under simulated flow conditions was studied by chronoamperometric technique. The effect of temperature and concentration on the scale forming behaviour of different compounds were also studied under the simulated flow conditions. In order to simulate the flow conditions a rotating disc electrode technique was employed. The mechanism of antiscaling behaviour of different chemicals was studied through electrochemical impedance spectroscopy. It was found that the flow velocity affected the efficiency of antiscalants. Polymer based compounds follow the growth modification adsorption mechanism, while compounds like EDTA and phosphonate follow nucleation modification absorption/chemisorption mechanism. Temperature and concentration of the scale forming compounds have a significant role in the scaling process, particularly at the low concentrations.

Discusses the particulation of organic barrier layers, based on laboratory‐bench data, obtained from the exposure of painted panels in low, high or neutral pHelectrolytes. It also discusses their compatibility with the succeeding and preceding layers and the galvanic interactions at the layer substrate interfaces. Aspects like substrate effect, leaching of the micaceous iron powder, role of high temperature and hydrodynamic disturbances and distribution of ultrafine particulates have been highlighted using potential versus time plot, AAS data, and galvanic current measurements and XRD analysis. Exposure tests conducted under ambient conditions and under very strong hydrodynamic disturbances, revealed superior properties of the SiC particulated epoxy based barrier layers.

The inhibition efficiencies of ethyl phosphonic acid (EPA) and 2‐chloroethyl phosphonic acid (2‐Cl EPA) in the presence of Zn²⁺, in controlling the corrosion of mild steel in a neutral aqueous environment containing 60ppm Cl^‐ have been evaluated by weight‐loss method and compared. It is observed that 2‐Cl EPA‐Zn²⁺ system has more inhibition efficiency than an EPA‐Zn²⁺ system. It is due to the electron withdrawing power of the Cl atom and its size. The nature of the protective film formed on the surface of the metal has been analysed by X‐ray diffraction, uv‐visible reflectance and luminescence spectra.

The synergistic effect of sodium salt of 2‐chloroethyl phosphonic acid (2‐Cl EPA) and Zn²⁺, in controlling corrosion of carbon steel in a neutral aqueous environment containing 60ppm Cl^–, was evaluated by weight‐loss and electrochemical methods. A formulation consisting of 300ppm 2‐Cl EPA and 300ppm Zn²⁺ was observed to deliver 95 percent inhibition efficiency. A suitable mechanism of corrosion inhibition has been proposed which is based on the results obtained from polarization study and uv‐visible absorption and reflectance spectra. 2‐Cl EPA‐Zn²⁺ system appears to function as a mixed inhibitor. The protective film consisted of Fe²⁺ ‐2‐Cl EPA complex, Zn(OH)₂ and oxides of iron. The film was found to be semiconducting in nature.

The inhibition efficiencies of 2‐carboxyethyl phosphonic acid (2 CEPA) – Zn²⁺ system and ethyl phosphonic acid (EPA) – Zn²⁺ system in controlling corrosion of mild steel in a neutral aqueous environment containing 60ppm CI^– have been compared. Polarization study reveals that both the systems function as mixed inhibitors. The inhibition efficiencies of these systems decrease with period of immersion due to the dissolution of the protective film as the period of immersion increases. The 2 CEPA – Zn²⁺ system has a better inhibition efficiency than the EPA–Zn²⁺ system. This is due to the fact that the amount of Fe²⁺– 2 CEPA complex present on the metal surface is higher than that of Fe²⁺– EPA complex, as revealed by fluorescence spectra. The molecular size of the iron phosphonate complex exercises a greater influence than the electronic (inductive) effect of the substituent in controlling corrosion of mild steel in chloride environment.

The beneficial effect of halide ions on the inhibition of corrosion of carbon steel in 20 per cent HCl solution in the presence of some nitrogen‐containing compounds, cetyl pyridinium chloride, cetyl pyridinium bromide, and hexamine was investigated using potentiodynamic polarisation measurements. Potentiodynamic polarisation studies revealed that all the tested compounds were of anodic‐type inhibitors. All of the compounds were able to reduce the corrosion of carbon steel and their performance was enhanced by the addition of iodide ions. The increase in surface coverage in the presence of the iodide ions indicated that iodide ions enhanced the absorption of inhibitor compounds on the metal surface. Auger electron spectroscopic analysis confirmed the joint absorption of the compounds with KI.

This information will be useful in the selection of materials and technology for the detection and removal of mercury ions at a low cost and with high sensitivity and selectivity. The purpose of this study is to provide the useful information for selection of materials and technology to detect and remove the mercury ions from water with high sensitivity and selectivity. The purpose of this study is to provide the useful information for selection of materials and technology to detect and remove the mercury ions from water with high sensitivity and selectivity.

Different nano- and bio-materials allowed for the development of a variety of biosensors – colorimetric, chemiluminescent, electrochemical, whole-cell and aptasensors – are described. The materials used for their development also make it possible to use them in removing heavy metals, which are toxic contaminants, from environmental water samples.

This review focuses on different technologies, tools and materials for mercury (heavy metals) detection and remediation to environmental samples.

This review gives up-to-date and systemic information on modern nanotechnology methods for heavy metal detection. Different recognition molecules and nanomaterials have been discussed for remediation to water samples. The present review may provide valuable information to researchers regarding novel mercury ions detection sensors and encourage them for further research/development.