Emad A. Badr

Synthesis, characterization and anticorrosion potentials of chitosan-g-PEG assembled on silver nanoparticles

Chitosan (Ch) grafted with poly(ethylene glycol) (Ch-g-mPEG) were synthesized using mPEG with molecular weights 2000 g/mol. The synthesized Ch-g-mPEG was characterized using gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR), and X-ray diffraction (XRD) techniques. Ch-g-mPEG silver nanoparticles has been synthesized and characterized by high-resolution transmission electron microscopy (HRTEM) and energy dispersive analysis of X-rays (EDAX). The synthesized Ch-g-mPEG and its nanostructure were examined as corrosion inhibitors for carbon steel in 1M HCl solution using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results revealed that the inhibition efficiency obtained by Ch-g-mPEG self-assembled on silver nanoparticles is greater than that obtained by Ch-g-mPEG only. Potentiodynamic polarization results reveal that the synthesized compound could be classified as mixed-type corrosion inhibitors with predominant control of the cathodic reaction. The results of EIS indicate that the both charge transfer resistance and inhibition efficiency tend to increase by increasing the inhibitor concentration.

Corrosion Inhibition performance of polyethylene glycol/ polytriethanolamine inhibitors on corrosion of carbon steel in acidic medium

The inhibition effect of three nonionic inhibitors on carbon steel corrosion in 1M H2SO4 was studied gravimetrically and electrochemically. Increasing the number of triethanolamine units in the inhibitor molecules increases their inhibition efficiencies. The inhibiting action of inhibitors was attributed to their adsorption on the carbon steel surface and the formation of dense protective layer which increased by increasing their concentration. Polarization measurements showed that inhibitors act as mixed-type inhibitor in 1 M H2SO4 with a domain of anodic one, and their inhibition on carbon steel proceeded by physical adsorption. Increasing the surface activity of inhibitors increased their inhibition efficiency

Performance of nonionic surfactants derived from tannic acid in preventing the acidic dissolution of carbon steel

Corrosion inhibition tendency of four modified nonionic tannic acid derivatives containing dodecyl, hexadecyl, octadecyl and oleyl chains on carbon steel was investigated using gravimetric measurements, polarization and electrochemical impedance spectroscopy (EIS). The effect of concentration and immersion time was studied. The results show that the synthesized inhibitors act as efficient inhibitor for the corrosion of carbon steel in 0.5 M H2SO4. Inhibition efficiency ( %) increases with the inhibitor concentration, and the maximum  % values at 400 ppm by weight are 94.4%-96.4% at 25 C. The adsorption of the different inhibitors on carbon steel surface obeys Langmuir adsorption isotherm. The inhibitors act as mixed-type inhibitor in 0.5 M H2SO4 and their inhibition on carbon steel is caused by physical adsorption (physisorption).EIS spectra exhibit one capacitive loop which indicates that the corrosion reaction is controlled by charge transfer process. The addition of the inhibitors to 0.5 M H2SO4 solutions enhances Rt values while reduces Cdl values.

Synthesis and Biological Activity of Some Amide-Based Cationic Surfactant complexes with Co (II) and Cu (II)

In this study, different cationic surfactants were prepared by esterfication of different fatty acids with ethanol then amidation of the prepared esters with N, N dimethyl ethylene diamine then quaternized the tertiary amines with benzyl bromide to produce a series of quaternary ammonium salts then preparing of metallocationic surfactants by complexing the cationic surfactants with cobalt chloride and copper chloride. Surface tension at different four temperatures of these metallocationic surfactants was investigated. The surface parameters including critical micelle concentration (CMC), maximum surface excess (Γmax), minimum surface area (Amin), efficiency (PC20) and effectiveness (πCMC) were studied and the thermodynamic parameters such as free energy of micellization (ΔG o mic) and adsorption (ΔG o ads), enthalpy (∆H o m), (∆H o ads) and entropy (∆S o m), (∆S o ads) were calculated. The antimicrobial activity of the prepared complexes was determined via the inhibition zone diameter against different microorganisms also the antimicrobial activity of the prepared complexes against sulfate reducing bacteria (SRB) was determined by the dilution method. The results indicate that these metallocationic surfactants have good surface properties and good biological