Nobl Foad El Boraei, Sayed S. Abd El Rehim and Hamdy H. Hassan
The purpose of this paper is to study the electrochemical behavior of Sn electrode in Na2B2O7 solutions in the absence and presence of NaNO3 as a pitting corrosion agent.
Abstract
Purpose
The purpose of this paper is to study the electrochemical behavior of Sn electrode in Na2B2O7 solutions in the absence and presence of NaNO3 as a pitting corrosion agent.
Design/methodology/approach
The electrochemical behavior of Sn electrode was studied by using cyclic voltammetry and potentiodynamic polarization measurements and complemented with scanning electron microscopy examinations.
Findings
This paper shows that in the absence of NO3 − ions, the anodic polarization of Sn electrode exhibits active/passive transition. Addition of various concentrations of NO3 − anions to the borate solution enhances active anodic dissolution and tends to break down the passive oxide film at a certain pitting potential. The pitting potential, and hence the pitting corrosion resistance, decreases with increasing NO3-ion concentration and temperature but increases with scan rate and repetitive cycling. Addition of CrO42−, WO42− or MoO42− oxyanions to the borate nitrate solution inhibits the pitting corrosion of Sn.
Originality/value
This is the first study that shows the effect of NO3 − ion as a pitting corrosion agent.
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Cyclic voltametry and potentiodynamic single sweep techniques are used to study the electrochemical behaviour of lead in Na2CO3 solutions containing various concentrations of ClO4‐…
Abstract
Cyclic voltametry and potentiodynamic single sweep techniques are used to study the electrochemical behaviour of lead in Na2CO3 solutions containing various concentrations of ClO4‐ as aggressive anion. The effects of different concentrations, in terms of destruction of passivity and initiation of pitting corrosion, were monitored with reference to the change in integrated anodic charge. It was found that Δqa (taken as a measure of the extent of pitting) varies linearly with log CClO4‐. The pitting corrosion potential, Epitting, varies with log CClO4‐ according to sigmoidal curves. These curves are explained on the basis of formation of passive, active and continuously propagating pits. Additions of aliphatic amines shift the pitting corrosion potential, Epitting, into the noble (positive) direction, indicating the inhibition action of the added amines on the pitting attack. Epitting varies with the logarithm of the inhibitor concentration according to: Epitting = a + b log Cinh. The inhibition of pitting corrosion by the aliphatic amines is assumed to be due to either competitive adsorption between the CO32– with ClO4‐ anions, and/or the chemisorption of the amine on the metal with the formation of a metal‐nitrogen coordination bond. The efficiency of these compounds as pitting corrosion inhibitors increases with the increase in the chain length of the alkyl group.
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Abd El‐Rehim Mohamed Al‐Kashif
There has been growth in Islamic finance both in Muslim countries and around the world during the last two decades. This has attracted interest of those concerned with combating…
Abstract
Purpose
There has been growth in Islamic finance both in Muslim countries and around the world during the last two decades. This has attracted interest of those concerned with combating crime in financial institutions. This article aims to highlight the Shari'ah law's normative framework in addressing the different aspects of financial crime.
Design/methodology/approach
The paper is a general discussion of the substantive Islamic law (Koran, Haddiths, etc.) and begins with an introduction of the significance of property in Islam. It then focuses on the Shari'ah perspective on financial crime.
Findings
It is found that Islam has stressed and asserted the importance of honesty in business and monetary dealings. Acts negatively affecting the economy are prohibited by Shari'ah under the division of criminal law developed by Islamic jurisprudence.
Originality/value
The paper shows that Islamic law widens the circle of protection against financial crimes.
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Zeinab Abdel Hamid, Sayed Abd El Rehim and Moustafa Ibrahim
The purpose of this work was to investigate the effect of Si content of steel substrate on the performance of the hot-dip galvanized layer. Moreover, the structure of the…
Abstract
Purpose
The purpose of this work was to investigate the effect of Si content of steel substrate on the performance of the hot-dip galvanized layer. Moreover, the structure of the galvanized layers and the corrosion performance of the galvanized steel in 3.5 per cent NaCl solution have been studied.
Design/methodology/approach
The galvanized layer has been formed by the hot-dip technique, and the influence of silicon content in the steel composition on the corrosion performance of the galvanized steel was estimated. The surface morphologies and chemical compositions of the coated layers were assessed using scanning electron microscopy and energy-dispersive X-ray analysis, respectively. Potentiodynamic polarization Tafel lines and electrochemical impedance spectroscopy (EIS) tests were used to evaluate the corrosion resistance of the galvanized steel in 3.5 per cent NaCl solution.
Findings
The results proved that adhere, compact and continuous coatings were formed with steel containing 0.56 Wt.% Si, while cracks and overly thick coatings were obtained with steel containing 1.46 Wt.% Si. Tafel plots illustrated that the corrosion rate of galvanized steel containing 0.08 and 0.56 Wt.% Si was lower than that of the galvanized steel containing 1.46 Wt.% Si. Also, the results of the EIS reveal that the impedance of the galvanized steel containing 0.08 and 0.56 Wt.% Si was the highest and the lowest, respectively, with the steel containing 1.46 Wt.% Si.
Social implications
Generally, in industry steels containing high amounts of silicon (0.15-0.25 Wt.%) can be galvanized satisfactory either by controlling the temperature (440°C) or adding Ni to the galvanized bath. The low temperature reduces the coating thickness; nickel amount must be controlled to prevent the formation of higher amounts of dross. This study proved that high Si steel of up to 0.56 Wt.% can be galvanized at 460°C without adding Ni to the galvanized bath and form adhere, compact, free cracks and have good corrosion resistance. Consequently, a social benefit can be associated with galvanizing high Si steel, leading to an increase in the cost of the process.
Originality/value
The results presented in this work are an insight into understanding the hot-dip galvanizing of high Si steel. The corrosion resistance of galvanized steel containing 0.56 Wt.% Si alloys has been considered as a promising behavior. In this work, a consistent assessment of the results was achieved on the laboratory scale.
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Hassan S. Emira, Alia A. Shakour, Sayed S. Abd El Rehim, Inas A. Saleh and Mohammed A. El‐Hashemy
The paper aims to evaluate the anti‐corrosion performance of inorganic pigments included in paint systems based on plasticized‐chlorinated rubber for carbon steel in different…
Abstract
Purpose
The paper aims to evaluate the anti‐corrosion performance of inorganic pigments included in paint systems based on plasticized‐chlorinated rubber for carbon steel in different environmental conditions.
Design/methodology/approach
Paint systems based on chlorinated rubber and inorganic pigments such as zinc chromate, zinc phosphate, red iron oxide and treated iron industry waste powder were prepared. Immersion in 3.5 percent salt solution, as well as outdoor exposure tests, were performed and the paint physico‐mechanical properties were tested to evaluate the paints' anti corrosive performance.
Findings
The concentration and the type of pigments included in the prepared paint systems control their anticorrosive performance.
Originality/value
The paper demonstrates how pigment consisting of treated iron industry waste powder could be used in anticorrosion paints for carbon steel.
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Hassan S. Emira, Alia A. Shakour, Sayed S. Abd El Rehim, Inas A. Saleh and Mohammed A. El‐Hashemy
The purpose of this paper is to report the use of zinc phosphate pigment as a chromate substitute for coatings on non‐ferrous metals (galvanized steel, pure aluminum, α‐brass and…
Abstract
Purpose
The purpose of this paper is to report the use of zinc phosphate pigment as a chromate substitute for coatings on non‐ferrous metals (galvanized steel, pure aluminum, α‐brass and pure copper).
Design/methodology/approach
Paint systems based on zinc chromate and zinc phosphate pigments were prepared. The paints were tested for their physico‐mechanical properties. Testing of the anticorrosive properties of the zinc phosphate pigment in comparison with zinc chromate pigment was carried out by accelerated corrosion exposure, i.e. immersion in 3.5 percent salt solution and exposure for one year at five outdoor stations.
Findings
The possibility of replacing chromate pigment was assessed and the “gap“ observable between the performance of zinc chromate and zinc phosphate pigments was noted.
Originality/value
The non‐toxic inhibitive pigment, zinc phosphate, incorporated into a plasticized‐chlorinated rubber binder, could be applied successfully for the protection of non‐ferrous substrates.
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Roma G. Elfadel, Hala M. Refat, H. Abdelwahab, Salem S. Salem, Mohamed A. Awad and M.A.M. Abdel Reheim
This paper aims to investigate the prepared modified alkyd and poly(ester-amide) (PEA) resins as antimicrobial and insecticide binders for surface coating applications.
Abstract
Purpose
This paper aims to investigate the prepared modified alkyd and poly(ester-amide) (PEA) resins as antimicrobial and insecticide binders for surface coating applications.
Design/methodology/approach
Salicylic diethanolamine and 4-(N, N-dimethylamino) benzylidene glutamic acid were prepared and used as new sources of polyol and dibasic acid for PEA and alkyd resins, then confirmed by: acid value, FT-IR and 1H-NMR. The coating performance of the resins was determined using measurements of physico-mechanical properties. The biological and insecticide activities of the prepared resins were investigated.
Findings
The tests carried out revealed that the modified PEA and alkyd enhanced both phyisco-mechanical and chemical properties in addition to the biological and insecticide activities. The results of this paper illustrate that the introduction of salicylic diethanolamine and 4-(N, N-dimethylamino) benzylidene glutamic acid within the resin structure improved the film performance and enhanced the antimicrobial activity performance of PEA and alkyd resins.
Research limitations/implications
The modified alkyd and PEA organic resins can be used as biocidal binders when incorporated into paint formulations for multiple surface applications, especially those that are exposed to several organisms.
Originality/value
Modified alkyd and PEA resins based on newly synthesized modifiers have a significant potential to be promising in the production and development of antimicrobial and insecticide paints, allowing them to function to restrict the spread of insects and microbial infection.
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Li Xianghong, Deng Shuduan, Fu Hui, Li Taohong and Mu Guannan
The purpose of this paper is to study the inhibition effect of Tween‐40 on the corrosion of cold rolled steel (CRS) in 1.0‐8.0 M HCl over the temperature range of 20‐50°C. It also…
Abstract
Purpose
The purpose of this paper is to study the inhibition effect of Tween‐40 on the corrosion of cold rolled steel (CRS) in 1.0‐8.0 M HCl over the temperature range of 20‐50°C. It also aims to make an attempt to correlate both thermodynamic parameters and kinetic parameters with the inhibition effect.
Design/methodology/approach
The inhibition efficiencies of Tween‐40 are investigated by weight loss and potentiodynamic polarization methods.
Findings
Tween‐40 acts as a good inhibitor in 1.0 M HCl, and inhibition efficiency increases with the inhibitor concentration, while it decreases with HCl concentration and temperature. The adsorption of inhibitor on the CRS surface obeys the Langmuir adsorption isotherm equation. The inhibition effect is satisfactorily explained by both thermodynamic and kinetic parameters. Polarization curves show that Tween‐40 is a mixed‐type inhibitor in hydrochloric acid.
Originality/value
The experimental data have been treated with adsorption theory and kinetic equations successfully. Both the thermodynamic and kinetic parameters can be obtained, and used in explaining the inhibition effect satisfactorily.
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Asyraf Abdullah and Siti Rabiatull Aisha Idris
This study aims to review the effect of copper percentage in Sn-based solder alloys (Sn-xCu, x = 0–5 Wt.%) on intermetallic compound (IMC) formation and growth after laser…
Abstract
Purpose
This study aims to review the effect of copper percentage in Sn-based solder alloys (Sn-xCu, x = 0–5 Wt.%) on intermetallic compound (IMC) formation and growth after laser soldering.
Design/methodology/approach
This study reviews the interfacial reactions at the solder joint interface, solder joint morphology and the theory on characterizing the formation and growth of IMCs. In addition, the effects of alloying and strengthening mechanism, including wettability, melting and mechanical properties are discussed.
Findings
This paper presents a comprehensive overview of the composition of tin-copper (Sn-Cu) solders with a potential to enhance their microstructure, mechanical characteristics and wettability by varying the Cu percentage. The study found that the best Cu content in the Sn-xCu solder alloy was 0.6–0.7 Wt.%; this composition provided high shear strength, vibration fracture life value and ideal IMC thickness. A method of solder alloy preparation was also found through powder metallurgy and laser soldering to improve the solder joint reliability.
Research limitations/implications
This study focuses on interfacial reactions at the solder joint interface, solder joint morphology, modelling simulation of joint strength and the theory on characterising the formation and growth of IMC.
Originality/value
The paper comprehensively summarises the useful findings of the Sn-Cu series. This information will be important for future trends in laser soldering on solder joint formation.
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M. Hassanein, M. Abd El Rahm, H. M. Abd El Bary and H. Abd El-Wahab
This paper aims to study the physical and chemical characteristics of inkjet titanium dioxide inks for cotton fabric digital printing.
Abstract
Purpose
This paper aims to study the physical and chemical characteristics of inkjet titanium dioxide inks for cotton fabric digital printing.
Design/methodology/approach
Different dispersing agents through the reaction of glycerol monooleate and toluene diisocyanate were prepared and then performed by using three different polyols (succinic anhydride-modified polyethylene glycol PEG 600, EO/PO Polyether Monoamine and p-chloro aniline Polyether Monoamine), to obtain three different dispersing agents for water-based titanium dioxide inkjet inks. The prepared dispersants were characterized using FTIR to monitor the reaction progress. Then the prepared dispersants were formulated in titanium dioxide inkjet inks formulation and characterized by particle size, dynamic surface tension, transmission electron microscopy, viscosity and zeta potential against commercial dispersants. Also, the study was extended to evaluate the printed polyester by using the prepared inks according to washing and crock fastness.
Findings
The obtained results showed that p-chloro aniline Polyether Monoamine (J) and succinic anhydride modified polyethylene glycol PEG 600 (H) dispersants provided optimum performance as compared to commercial standards especially, particle size distribution data while EO/PO Polyether Monoamine based on dispersant was against and then failed with the wettability and dispersion stability tests.
Practical implications
These ink formulations could be used for printing on cotton fabric by DTG technique of printing and can be used for other types of fabrics.
Originality/value
The newly prepared ink formulation for digital textile printing based on synthesized polyurethane prepolymers has the potential to be promising in this type of printing inks, to prevent clogging of nozzles on the printhead and to improve the print quality on the textile fiber.