الفهرس 
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Abstract
Summary
The present work has been devoted to study the recyclization of some expired drugs, namely Solo Sept, Slim-lax, Well Derm and Megavit zinc, as metallic corrosion inhibitors for copper (C10100) in nitric acid solution.
This work contains three basic chapters:
Chapter (1): includes an introduction to expired drugs, expired drugs as corrosion inhibitors, properties of copper, corrosion of copper in nitric acid solution and the literature survey on metallic corrosion inhibition by pharmaceutical drugs in aqueous solutions.
Chapter (2): deals with the experimental part including the description of the inspected drugs, preparation of solutions, and presenting the used techniques in the study; weight loss, open circuit potential measurements, potentiodynamic polarization, electrochemical impedance spectroscopy and cyclic voltammetry.
Chapter (3): presents the results and discussion of the data obtained. This chapter is divided into seven sections as follows:
Section (1): shows weight loss results and discussion for the corrosion of copper (C10100) in 2M HNO3 solution in increasing concentrations of the inspected drugs at room temperature The results revealed that by increasing the concentration of the drug, the weight loss of copper samples is decreased.
Section (2): shows the variation of corrosion potential, Ecorr of copper with time versus saturated calomel electrode (SCE), in 2M HNO3 solution with various concentrations of the inspected drugs, with maximum time of 120 seconds. The results revealed that the open circuit potential values are almost stabilized but shifted in the negative direction as the concentration of the inspected drugs is increased. These results are clue for the homogenous form of corrosion and the adsorption of drug molecules on the active sites.
Section (3): shows the potentiodynamic polarization measurements and discussion. The results revealed that, upon the addition of the drug, both the corrosion current density (Icorr) and the corrosion rate (CR) decreased significantly and the percentage inhibition efficiency (IE %) increased. The corrosion potentials (Ecorr) were shifted slightly towards negative sites, with shifts less than ±85 mV speculating that the inspected drug retards both anodic and cathodic reactions and behaves as a mixed type inhibitor.
Section (4): shows the concept of impedance, Simplified Randles Cell and electrochemical impedance spectroscopy measurements and discussion. The results revealed the decrease in double layer capacitance (Cdl) value and the increasing RP value upon the addition of the drug speculating that the inspected drugs act as efficient corrosion inhibitors for copper (C10100) in 2M HNO3.
Section (5): shows the cyclic voltammetry results and discussion. The results revealed that both overall positive and negative charges are decreased upon the addition of increasing concentrations of the inspected drugs.
Section (6): Tafel polarization is employed to find out the values of surface coverage (θ) at different drug concentrations to explain the best fit isotherm for the adsorption process. The results are best fitted by Langmuir adsorption isotherm.
Section (7): Shows the calculations of thermodynamic parameters and their discussion.