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.
Coordination compound films of 1-phenyl-5-mercaptotetrazole on copper surface
Abstract The chemical nature of the coordination compound film formed by reacting PMTA (1-phenyl-5-mercaptotetrazole) with a copper surface has been studied by accelerated corrosion tests, linear sweep voltammetry (LSV), cyclic voltammetry (CV), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). These studies show that, in retarding the corrosion of copper substrate, the film is superior to those formed by TTA (tetrazole), BTA (benzotriazole), HBTA (hydroxybenzotriazole), MBT (2-mercaptobenzothiazole), MBI (2-mercaptobenzo-imidazole), 2-AP (2-aminopyrimidine), IBM (imidazole) and chromates. The surface film has been characterized and found to be a polymeric complex of Cu–PMTA. The mechanism for film formation and relationships between this novel film structure and the observed inhibition behavior are discussed.
A New Vacuum Pressure Infiltration CFRP Method and Preparation Experimental Study of Composite
In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa.