Organic chemicals, corrosion inhibition

Corrosion inhibitor - corrosion inhibitors are chemicals which are added to the electrolyte or a gas phase (gas phase inhibitors) which slow down the - kinetics of the corrosion process. Both partial reactions of the corrosion process may be inhibited, the anodic metal dissolution and/or the cathodic reduction of a redox-system [i]. In many cases organic chemicals or compounds after their reaction in solution are adsorbed at the metal surface and block the reactive centers. They may also form layers with metal cations, thus growing a protective film at the surface like anodic oxide films in case of passivity. Benzo-triazole is an example for the inhibition of copper cor-... 

Copper does form compounds with BTA in solutions. The pH of the solution influences the stability of these compounds and thereby the effectiveness of their corrosion inhibition. For the same reason, for this chemical, pH also influences the removal of BTA from a copper film after copper CMP. The reaction between BTA and copper favors the release of BTA at low pH. In order to minimize organic contamination, the interaction between the organic chemical and the film to be polished has to be... 

S.N. Raicheva, B.V. Aleksiev, E.I. Sokolova, The effect of the chemical sttucture of some nitrogen-and sulfur-containing organic compounds on their corrosion inhibiting action, Corros. Sci. 34 (1993) 343-350. 

The mechanism of inhibition action by organic compounds is adsorption. There are two types of adsorption, namely, physiosorption and chemisorption. For physiosorption, corrosion inhibition may be a result of the formation of mechanical barriers by inhibitor species. This will hinder the movement of ionic species from and to the surface of the corroding metal. On the other hand, for chemisorption, the chemical reaction takes place on the surface of the corroding metal, with subsequent formation of a thin coating. This hinders movement of species to and from the corroding surface as well. The characteristics of physiosorption are as follows ... 

Numerous experimental works have been devoted to corrosion inhibition, whereas atomistic theoretical studies appeared only recently. A detailed understanding of the chemical interaction between the organic molecule and the substrate (metal without or with a surface oxide film) is the key to understanding and control of corrosion inhibition [2]. 

The corrosion inhibition is a key issue to protect the integrity of the pipelines and to preserve the assets. The use of organic chemicals those usually incorporate film forming amines and their salts are common practices applied nowadays for corrosion inbition. 

The corrosion inhibition effect of organic phosphonic acids can be synergetically enhanced by bivalent cations. This effect has not so far been related unambiguously to the chemical composition and structure of the inhibitor layer. Several bivalent cat-... 

Steam systems. Copper and copper alloys resist attack by pure steam, but if carbon dioxide, oxygen, or ammonia is present, condensates can be quite corrosive to copper alloys. Modem power utility boiler feedwater treatments commonly include the addition of organic amines to inhibit the corrosion of iron components of the system by scavenging oxygen and increasing the pH of the feedwater. These chemicals tend to release ammonia, which can be corrosive to some copper alloys. 

Surface-modified nanoparticles are good candidates for corrosion-inhibiting additives. Nanoparticles have high smface areas (high loadings of organic corrosion inhibitors) and novel surface ehemistries (enhanced chemical reactivity) and offer multiple properly enhancements without trade-offs. However, there are also some praetieal limitations to the use of nanopartioles as corrosion inhibitors. These inelude eost (paints are a conunodity product), accessible surface chemistry (one needs to tether the eorrosion inhibitor to the nanopartiele surface) and a release meehanism. 

Wastage was caused by exposure to oleic acid and short-chain organic acids in the rolling oil. Fatty acids break down to form shorter-chain acids in service. However, oleic acid, of and by itself, is fairly corrosive. Attack due to oleic acid can be reduced substantially using appropriate chemical inhibition. 

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