The Inhibited Effect of Cysteine Towards the Corrosion of Copper in Nitric Acid Solution
The detailed study of cysteine (Cys) as corrosion inhibitor for copper in nitric acid solution has been performed through weight loss, electrochemical polarization, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) measurements. The effect of inhibitor concentration, temperature and immersion time against inhibitor action was investigated. Results show that Cys may be used as an efficient inhibitor for copper in nitric acid at higher temperatures (98% at 50°C). Potentiodynamic polarization studies reveal that Cysteine acts as a mixed-type inhibitor without any change in the mechanism of hydrogen evolution. The adsorption of this compound on copper surface obeys Langmuir's adsorption isotherm and has a chemisorptions mechanism.
L-cysteine/polydopamine nanoparticle-coatings for copper corrosion protection
Abstract Polydopamine (PDA) coating on a copper surface was successfully prepared using a two-step process. In the first stage, in order to improve the adhesion of PDA on the copper surface, a self-assembled monolayer of L -cysteine was deposited on a bare copper. Thereafter, the PDA coating was fabricated through the chemical adsorption and auto-polymerization of the dopamine hydrochloride on the L -cysteine-coated copper surface. The inhibitory behavior of L -cysteine and PDA films has been investigated in aqueous 3.5% NaCl solution using potentiodynamic polarization and electrochemical impedance spectroscopy. It is demonstrated that the L -cysteine/PDA coating provides significant protection against copper corrosion.
Cu(I) Complexes with heterocyclic thiones and triphenylphosphine as ligands. The crystal structure of [Cu(tzdtH)2 (PPh3)2]NO3
Abstract The reactions of bis(triphenylphosphine)copper(I) nitrate with heterocyclic thiones (L) [L = pyridine-2-thione (py2SH), pyridine-4-thione (py4SH), pyrimidine-2-thione (pymtH), 1,3-thiazolidine-2-thione (tzdtH), 1-methyl-1,3-imidazoline-2-thione (meimtH), benz-1,3-imidazoline-2-thione (bzimtH 2 ), benz-1,3-thiazoline-2-thione (bztzH), benz-1,3-oxazoline-2-thione (bzoxtH), 5-nitro-2-benz-l,3-imidazoline-2-thione (nbzimtH 2 ) and quinazolinone-2-thione (qnotH 2 )] lead to the formation of mononuclear complexes of the general formula [Cu(L) 2 (PPh 3 ) 2 ]NO3. The complexes have been characterized by elemental analysis, infrared, UVVis and NMR spectroscopy. The crystal structure of [Cu(tzdtH) 2 (PPh 3 ) 2 ]NO 3 has been determined by single-crystal X-ray diffraction methods. The colorless crystals are monoclinic, space group P 2 1 / c with a = 16.314(2), b = 9.981(2), c = 25.799(3) A, β = 89.39(1)°, V = 4200 A 3 and Z = 4.