High Anticorrosion Properties Research Articles

Anticorrosive properties of N-acetylmethylpyridinium bromides

The inhibiting action of N-acetylmethylpyridinium bromides on the corrosion of low-carbon steel in a 3 M sulfuric acid solution at 20, 40, 60, and 80°C was studied. The mechanism of their protective action was examined using electrochemical methods. Compounds exhibiting high anticorrosive properties at elevated temperatures were found.

Polyaniline: a conductive polymer coating for durable nanospray emitters

Despite the tremendous sensitivity and lower sample requirements for nanospray vs. conventional electrospray, metallized nanospray emitters have suffered from one of two problems: low mechanical stability (leading to emitter failure) or lengthy, tedious production methods. Here, we describe a simple alternative to metallized tips using polyaniline (PANI), a synthetic polymer well known for its high conductivity, anticorrosion properties, antistatic properties, and mechanical stability. A simple method for coating borosilicate emitters (1.2 mm o.d.) pulled to fine tapers (4 ± 1 μm) with water-soluble and xylene-soluble dispersions of conductive polyaniline (which allows for electrical contact at the emitter outlet) is described. The polyaniline-coated emitters show high durability and are resistant to electrical discharge, likely because of the thick (yet optically transparent) coatings; a single emitter can be used over a period of days for multiple samples with no visible indication of the destruction of the polyaniline coating. The optical transparency of the coating also allows the user to visualize the sample plug loaded into the emitter. Examples of nanospray using coatings of the water-soluble and xylene-soluble polyaniline dispersions are given. A comparison of PANI-coated and gold-coated nanospray emitters to conventional electrospray ionization (ESI) show that PANI-coated emitters provide similar enhanced sensitivity that gold-coated emitters exhibit vs. conventional ESI.

Structural properties of new siliconized coatings formed by pyrolytic decomposition of pure TPOS

New anticorrosion siliconized coatings are formed by pyrolytic decomposition of sprayed pure tetraphenoxy silane (TPOS) on surfaces of carbon steel specimens, in a preheated furnace within a temperature range 500–650°C. The optimum conditions for developing highly corrosion resistant siliconized coatings, are decided by the aids of structural and composition analysis techniques. By the aid of EDXRF, SEM, Ultra Sonic Cleaner (USV), cross-edged SEM micrographs, O.M. and Thin Film On Surface (TFOS) software program, the optimal thickness, structure free voids interface and maximum adhesion properties of the produced siliconized coatings, were determined at 600°C for pyrolytical time 45 min. Evaluation of the coatings' composition yielding a high anticorrosion property is fully detailed by the aid of XRD analysis, electrochemical dissolution in different acidic media and adhesion techniques. The microstructure of the optimum siliconized coatings is regular in shape, size, orientation and boundaries of the formed bulky aggregated particles. Also the striations around the coatings' particles are mostly narrow. The strong adhesion property of the coating/metal surface interface, is assessed on the basis of the `go, no go' principle and is related to the inner diffusion of silica (rooting phenomenon). The variation in the constituents' ratios of the produced coatings at different temperatures is attributed to the rate of interconversion of the microcrystallite SiO 2 to crystalline phases and rate of interaction between the diffused iron, Fe 2+, and the crystalline phases of SiO 2. Electrochemical dissolution performance for uncoated and coated electrodes in the range of 0.1–10 M HCl solutions reveal that no significant corrosion behavior is observed. However, the variation between anodic and cathodic routes, is referred to the formation of strong passive irreversible phases on the electrode's surface. These phases could initiate from metal ions (Fe 2+) either provided by the metal surface (in case of uncoated electrodes) or by the siliconized coatings' enriched iron constituents (in case of coated electrodes).

Influence of Crystalline Structure and Sulfur Inclusion on Corrosion Properties of Electrodeposited CoNiFe Soft Magnetic Films

The corrosion resistance of soft magnetic films is an important property to be considered in the manufacture of magnetic devices. We investigated the corrosion behavior of the electrodeposited CoNiFe film with desired soft magnetic properties by varying the crystalline structure and the amount of included sulfur. The corrosion property in 2.5% NaCI solution depends largely on the sulfur content and also on the structure of the film. Although the CoNiFe film contains more than 13 atom % Fe, the film of face‐centered to body‐centered cubic mixed crystals exhibits a high anticorrosion property because of very small grain size with essentially no sulfur inclusion (<0.1 atom %). © 1999 The Electrochemical Society. All rights reserved. ©2001 American Geophysical Union

Corrosion behaviour of surface titanium layers in acid solutions after nitrogen thermodiffusion saturation

The influence of structure and phase compositions of nitrided BT1-0 titanium surface layers on the corrosion properties in 30% H 3 PO 4 solution has been investigated. It has been shown that formation of the oxynitride film on the Bt1-0 surface provides high anticorrosive properties of titanium in 30% H 3 PO 4 solution as well as in 10% H 2 SO 4 solution, though proves to be ineffective in 10% HCl solution.

Effects of the functional groups of polystyrene on its adhesion improvement and corrosion resistance

Novel functionalized polystyrenes having groups such as epichlorohydrin, epoxy, acetyl, C=C double bond, and carboxyl were synthesized by the reaction of polystyrene with epichlorohydrin, unsaturated hydrocarbons, and organic anhydrides in the presence of Lewis acid catalysts. The adhesion capability and corrosion resistance of the new synthesized functionalized polystyrenes to metals under various conditions were investigated. A very good relationship was observed between the quantity of functional groups bonded to the aromatic rings of the polystyrenes and the adhesion and corrosion resistance properties of the polyfunctionalized polystyrenes. It was also observed that the new polyfunctionalized polystyrenes obtained by chemical modification with maleic anhydride, acetic anhydride, isoprene, butadiene, and epichlorohydrin in the presence of cationic catalysts resulted in high adhesion and anti-corrosion properties.

S-substituted mercaptoacetic esters as anticorrosion additives to lubricating oils

1. 1. S-substituted mercaptoacetic esters possess high anticorrosion properties and are more effective than corresponding derivatives of mercaptopropionic esters and unsubstituted sulphides. 2. 2. The linear dependence of chemical shifts of methylene protons of the —SCH 2— COO group of S-substituted mercaptoacetic esters on the induction constants of the substituent has been found. This is characterized by a fairly high correlation coefficient ( r=0·98) and indicates that the effect of substituent R at the sulphur atom on screening of methylene protons is communicated by the system of chemical bonds mainly by an induction mechanism. 3. 3. The combined presence of the sulphide sulphur atom and an ester group leads to an increase in the anticorrosion activity of the sulphides on account of the electronic interactions arising between these groups and occurring by a π-induction mechanism.

On the resistance of aluminized steel in high temperature water

Due to its high anti-corrosion properties under room temperature and also to its high thermal resistance, the applications of aluminized steel has remarkably been increased in recent time. On its resistance to corrosion in high temperature water, however, no study has so far been made. If its high resistance in high temperature water is proved, it is well considered that the aluminized steel will get more promissible as a material for boilers, vessels for some chemicals and others.In this connection, by use of aluminized steel plates which have deferent chemical compositions, an experiment has been made for studying on their resistance to corrosion in high temderature (250°C) distilled and city water respectively by way of measuring the degree of corrosion, electrode potential, X-ray diffraction and so on.The findings are as follows:1) The degree of corrosion in primary stage is different according to the chemical composition of base steel.2) The corrosion resistance of the material in the distilled water at 245°C is little different from that in the city water at same temperature.3) The corrosion film formed on the surface of the material is mostly composed of Bohmite (α-Al2O3·H2O), but Diaspore(β-Al2O3·H2O) is also formed a little both in distilled and city water at the temperature of 245°C.

On the wet and dry corrosion test of the aluminium alloysfor casting, No. 4 and No. 7

The anti-corrosion property of the aluminium alloy No. 4C for casting, which has good castability and weldability, and excellent air tightness and shock resisting property, is compared in corrosion test, especially in wet and dry corrosion test, with that of the aluminium alloy No. 7B for casting which is known to have the best anti-corrosion property good mechanical properties in aluminium alloys. This study was made for the purpose of confirming the utilization of No. 4C in industrial use. Recently, the usage of aluminium alloys has been drastically increased and the high anti-corrosion properties of the alloys has been getting more desired. No. 7B alloy requires the high level technique in working and has various problems in pratical uses in spite of its good anti-corrosion property, No. 4 alloy was selected to be studied for the purpose of substituting the No. 7 alloy. The characteristics of the alloy in the case of the periodic wet and dry corrosion test was particularly examined. (3%NaCl 0.15%H2O2) solution was used for this test.