Nathir A. F. Al-Rawashdeh

Cationic surfactant as corrosion inhibitor for aluminum in acidic and basic solutions

Purpose – To investigate the inhibiting effect of the cationic surfactant cetyl trimethylammonium chloride (CTAC) on aluminum (Al).Design/methodology/approach – Pure aluminum rods were immersed in hydrochloric acid (HCl) and sodium hydroxide (NaOH) solutions for weight‐loss tests and potentiostatic polarization measurements.Findings – The inhibition action depends on the concentration of the inhibitor, the concentration of the corrosive media, and the temperature. The inhibition efficiency in NaOH was higher than that in HCl solutions. In both acidic and basic media, the increase in temperature resulted in a decrease of the inhibition efficiency and a decrease in the degree of surface coverage. The results were indicative of increased aluminum dissolution with increasing temperature. It was found that adsorption of CTAC on the aluminum surface follows Temkins isotherm in HCl and Langmuirs isotherm in NaOH.Originality/value – Clarifies the effects of concentration and temperature on the inhibition effici...

UV/Visible and infrared spectra of polyethylene/nanoscopic gold rod composite films: effects of gold particle size, shape and orientation.

Abstract We have prepared nanoscopic gold rods of various radii and aspect ratios via anodic aluminum oxide - based template synthesis, and incorporated these particles into polyethylene films. The resulting composite films exhibit linear dichroic properties which result from a net orientation of the rods. The plasmon resonance absorption maxima occur at the longest wavelengths when the incident electric field is polarized along the direction of particle orientation, and are blue-shifted as the polarization angle is directed perpendicular to the orientation direction. These results are in general accord with Rayleigh scattering theory, though effective medium type approaches which account for inter-particle interaction yield a closer quantitative agreement. We will also discuss the application of these composite materials to surface-enhanced infrared spectroscopy.

Corrosion Behavior of Copper in Chloride Media

The electrochemical behavior of copper in 0.05 M HCl and 0.05 M NaCl carried out at open-circuit potential and at constant anodic potential after one hour has been investigated using electrochemical impedance spectroscopy (EIS) at 20 °C, 40 °C and 60 °C. The formation of copper chloride (CuCl) film does not protect copper from dissolution in the chloride media. The physical properties of the passive film such as, polarization resistance (Rp), capacitance (C), loss fac- tor (%P), Warburg diffusion coefficient (W) and Kugel diffusion constant (k) were obtained from EIS measurements. Also, the radii of the pores formed as a result of anodic polarization have been calculated.

Green Approach to Corrosion Inhibition of Mild Steel by Lignin Sulfonate in Acidic Media

The inhibition effect of lignin sulfonate against corrosion for mild steel in acidic solution has been examined by means of FTIR (fourier transform infrared spectroscopy), FAA (flame atomic absorption) spectroscopy, SEM (scanning electron microscope), EDS (energy dispersive X-ray spectroscopy), and mass loss techniques. The results revealed that lignin is a beneficial inhibitor for mild steel corrosion in acidic medium. It has been further found that Langmuir adsorption isotherm is obeyed by the tested lignin s adsorption over the surface of mild steel. The range of inhibition efficiency (IE) in 2 mol • L−1 HCl was found to be 75.88%–87.88% for Reax 88A, 40.72%–60.32% for Reax 88B, and 54.32% –63.03% for Reax 100M, after immersed at 298 K for 24 h time.

Efficient production of methyl viologen cation radicals using RuII systems

Abstract A number of Ru II -diimine complexes were used to photosensitize methyl viologen cation radical (MV + ) production in the presence of ethylenediaminetetraacetic acid (EDTA). An unusually high quantum yield (π(MV + ) = 1.88) was obtained for [Ru(bpz) 2 dpq] 2+ (bpz = 2′,2-bipyrazine; dpq = 2,3-di-(2′-pyridyl)-quinoxaline) at pH 11. This value is higher than any previously known for Ru II complexes. The quantum yield is discussed in terms of the electron transfer quenching process and the cage escape effects which affect geminate recombination of the redox species. Time-resolved transient absorption spectra were used to study the formation of MV + and Ru I in the case of [Ru(bpz) 2 (dpq)] 2+ .

Preparation of 3-(9-Anthryl)acrylates and 9-Aroylethenylanthracenes as Pi-Extended Anthracenes and Their Diels–Alder Type Adducts with Electron-Poor Dienophiles

ABSTRACT (E)-3-(9-Anthryl)acrylates and (E)-9-aroylethenylanthracenes have been prepared by solventless Wittig olefination with conjugated phosphoranes. The (E)-3-(9-anthryl)acrylates were brominated to give (E)-3[10-{9-bromoanthryl}]acrylates, which could be subjected to Suzuki reactions with arylboronic acids to produce (E)-3-[10-{9-arylanthryl}]acrylates as pi-extended systems. The compounds thus prepared were subjected to Diels–Alder reactions, partly under solventless conditions.