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Article
Publication date: 1 February 1996

Mervette El‐Batouti

Measures the rates of the copper (II)/steel cementation reaction in organic‐water mixture solvent at 25°C using an atomic absorption spectrophotometer. The relation…

Abstract

Measures the rates of the copper (II)/steel cementation reaction in organic‐water mixture solvent at 25°C using an atomic absorption spectrophotometer. The relation between In C0/C and t in the absence of non‐aqueous solvent and at very diluted CuSO4 solution is given by In C0/C= k.A.t/V, while in the organic‐water mixture the data fit the equation of In C0lC= b+kAt/V. Finds that the rate constant of the cementation reaction increases with increasing the dielectric constant of the mixture. The rate of cementation increased in the order: water > methanol > ethanol > n‐propanol > 2‐propanol.

Details

Anti-Corrosion Methods and Materials, vol. 43 no. 2
Type: Research Article
ISSN: 0003-5599

Article
Publication date: 1 June 1995

Mervette El Batouti

Although much work has been done on the rate of diffusion‐controlled corrosion under forced convection (moving solution), little has been done on the rate of…

Abstract

Although much work has been done on the rate of diffusion‐controlled corrosion under forced convection (moving solution), little has been done on the rate of diffusion‐controlled corrosion under natural convection which takes place in stagnant solutions. In diffusion‐controlled corrosion, the rate of corrosion is determined by the rate of transfer of the depolarizer or by the rate of removal of the corrosion products to or from the corroding surface respectively. In the case of stagnant solutions, transfer of the depolarizer to the corroding surface and removal of the corrosion products take place by diffusion and natural convection which arises from the density difference between the bulk solution and the interfacial solution, the interfacial solution being more dense than the bulk solution owing to the dissolution of the metal at the interface. This density difference result in a downward flow which enhances the rate of diffusion controlled corrosion. According to the hydrodynamic boundary layer theory the magnitude of natural convection depends on the physical properties of the solution us well as the geometry and orientation of the solid surface. Diffusion‐controlled metallic dissolution of vertical and horizontal surfaces has been studied earlier.

Details

Anti-Corrosion Methods and Materials, vol. 42 no. 6
Type: Research Article
ISSN: 0003-5599

Article
Publication date: 13 November 2007

Mervette El‐Batouti

The object of the present work is to study the kinetics of removal of Pb++ on zinc rods in the presence and absence of three surface active substances (SAS) at different…

260

Abstract

Purpose

The object of the present work is to study the kinetics of removal of Pb++ on zinc rods in the presence and absence of three surface active substances (SAS) at different concentrations of SAS and different temperatures.

Design/methodology/approach

The paper uses a range of recently published (1973‐2003) works, which aim to provide practical and theoretical information about lead, which is a very toxic metal.

Findings

Lead tends to accumulate a sediment, from which it can be released by various processes of remobilization and in many cases it enters the food chain and is concentrated in fish and other edible organisms. The reaction can be considered as taking place via six steps.

Research limitations/implications

The work is a list of recent papers which have been published in different European journals and magazines.

Practical implications

The determination of change of Pb++ concentrations was carried out using a Perkin‐Elmer atomic absorption Spectrophotometer.

Originality/value

The rate of PbII/Zn cementation reaction in the presence of surfactants as non‐ionic (Triton‐X‐100), anionic (SDS) and cationic (CTAB) decreased compared with the blank solution (lead nitrate solution). The order of decreasing rate was as follows: Triton‐X‐100 > CTAB > SDS. The rate of cementation was increased by temperature and the value of ΔE* ranged between 27 and 33 kJmol−1, which indicated that the reaction is a diffusion‐controlled process. The presence of two different SAS in the solution is more effective than the presence of one only.

Details

Anti-Corrosion Methods and Materials, vol. 54 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 December 2004

Aida B. Tadros and Mervette El‐Batouti

Three thiosemicarbazone derivatives were synthesised: p‐chlorobenzylideneamino thiosemicarbazone, p‐itrobenzylideneamino thiosemicarbazone and pN,N

Abstract

Three thiosemicarbazone derivatives were synthesised: p‐chlorobenzylideneamino thiosemicarbazone, p‐itrobenzylideneamino thiosemicarbazone and pN,N ′‐dimethylminobenzylideneamino thiosemicarbazone. The structures of these compounds were characterised by elemental analysis, IR, 1H NMR and UV spectral measurements. The antifouling properties of the compounds were evaluated through the incorporation of each compound in a marine coating system and testing the system in Alexandria Eastern Harbour water. The results are discussed in the light of the leaching rate of the compounds from their paint films, and their interaction with paint matrix.

Details

Anti-Corrosion Methods and Materials, vol. 51 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 October 1998

Mervette El‐Batouti

The rate of copper dissolution in presence of phosphoric acid‐formaldehyde mixtures were studied by measuring the limiting current which represents the rate of…

650

Abstract

The rate of copper dissolution in presence of phosphoric acid‐formaldehyde mixtures were studied by measuring the limiting current which represents the rate of electropolishing. It is found that the rate of dissolution is decreased by increasing H3PO4 concentration, electrode height and mole fraction of formaldehyde. It is found that the decrease in the rate of dissolution ranges from 24 per cent to 63.88 per cent depends on the mole fraction of formaldehyde. The thermodynamic parameter ΔH* ΔG* ΔS* was calculated.

Details

Anti-Corrosion Methods and Materials, vol. 45 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 June 1999

Mervette El‐Batouti

The rates of copper/zinc cementation reaction in isobutanol‐water mixture was measured at different temperatures using an atomic absorption spectrophotometer. The rate of…

Abstract

The rates of copper/zinc cementation reaction in isobutanol‐water mixture was measured at different temperatures using an atomic absorption spectrophotometer. The rate of cementation decreases with increasing the percentage composition of alcohol, and increases by increasing temperature and the rate of rotation. Thermodynamic parameters ΔH*, ΔG* and ΔS* were calculated.

Details

Anti-Corrosion Methods and Materials, vol. 46 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

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