A. A. Ghoneim

Electrochemical behavior of surgical 316L stainless steel eye glaucoma shunt (Ex-PRESS) in artificial aqueous humor

A novel system of electrodeposited gold nanoparticles on a carbon paste electrode was utilized as an electrochemical sensor to monitor the corrosion performance of 316L stainless steel alloy in aqueous humor containing moxifloxacin hydrochloride (MFH) drug. Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and potentiodynamic polarization measurements were used to estimate the corrosion performance of 316L stainless steel alloy in aqueous humor with immersion time. The experimental data was confirmed by scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDX) and antibacterial activity. All techniques conform well to each other and confirmed that the tested alloy corrosion decreases with increasing immersion time in aqueous humor. Corrosion is more inhibited after the addition of MFH drug. In addition, as the concentration of the drug increases, the protection efficiency of the tested alloy increases. This behavior was confirmed by sensing the drug concentration with time using the modified carbon paste electrode.

Cyclic Voltammetric Studies on Selected Tin-Silver Binary Alloys in Sodium Hydroxide Solution

Abstract The electrochemical corrosion and passivation behavior of four selected tin-silver alloys, xSn-Ag (x = 26, 50, 70, and 96.5 wt%) (II through V), in addition to their pure metallic components, Ag(I) and Sn(VI), were investigated in aqueous sodium hydroxide (NaOH) solution. The techniques used are linear sweep cyclic voltammetry and electrochemical impedance spectroscopy (EIS). In general, for all studied samples, the cyclic voltammograms show that increasing the scan rate shifts the passivation peak potential (Ep,a) positively and the reduction peak potential (Ep,c) negatively with a concomitant increase in both the passivation peak current density (ip,a) and the reduction peak current density (ip,c). EIS results investigate that the total resistance (RT) and the relative thickness (1/C) of the passive layers on the six tested electrodes are both found to increase with time of immersion, being more pronounced for sample II. Although this silver-rich alloy (74 wt%) has the most protectiveness among...