Inhibitory Properties of Neomycin Thin Film Formed on Carbon Steel in Sulfuric Acid Solution. Electrochemical and AFM Investigation

Abstract

15Our study aims to implement a strategy to reduce the carbon steel corrosion rate in sulfuric acid

Copper corrosion inhibitors based on polyvinyl alcohol and silver nanoparticles

“…Distilled water was used to prepare three corrosive media consisting of: 0.1 mol L -1 HCl solution; 0.1 mol L -1 HCl solution containing 0.1% PVA; 0.1 mol L -1 HCl solution containing nAg/0.1% PVA. The nAg/PVA inhibitor was prepared as follows: (1) in 90 mL of 0.1% PVA solution 0.05 g of silver nanoparticles was added; the mixture was kept under continuous stirring (300 rpm), for 120 min, until orange color was observed; (2) the excess of nAg was filtered and the nanodispersion with a seemingly homogeneous appearance was analyzed by UV--Vis spectrophotometry using a Varian Cary 50 spectrophotometer with CaryWin UV software, the nAg absorbance maximum being found at 404.0 nm, similar to previous studies [22,23].…”

Poly(Vinyl Butyral-co-Vinyl Alcohol-co-Vinyl Acetate) Coating Performance on Copper Corrosion in Saline Environment

“…2b) designs for impedance, almost overlapped curves for standard copper and the one treated in methanol and a completely distinct one for Cu-PVBA, having the highest response in the low frequency area, respectively at 0.1 Hz. The Bode impedance curves indicate that the copolymer macromolecules were adsorbed on the metal surface, modeling a surface film that leads to the increase of copper impedance response (Z) and by default the charge transfer resistance (Rct) [35][36][37][38], the results being in good agreement with those observed from Nyquist diagram. On the other hand, the phase Bode diagram shows that: (i) the standard copper forms a maximum of the phase angle at -46.3 degrees, generating a small loop followed by an uncertain sholder with a wide maximum located at -44.5 degrees that slowly increases until 0.1 Hz; (ii) a large phase angle maximum around -48.8 degrees was formed in the case of Cu-Me sample exhibited in NaCl solution which gradually decreases in the area of very low frequencies, indicating a slightly different behavior from that of the standard copper due to the chemically finished of the metallic surface with methanol; (iii) a completely distinct curve was recorded for Cu-PVBA having a phase angle well-contoured maximum at -57.1 degrees, indicating a different chemical composition of the upper layer [38] due to the PVBA macromolecules adsorbed on the surface, which drastically changes the metal behavior to corrosion.…”

“…3b, the slope of the straight lines drawn as tangents to the polarization curves recorded in a potential range close to the corrosion potential was computed [37,40]. Thus, the polarization conductance (Cp) was determined from the corresponding line slope (di/dE) [37,40] and implicitly the polarization resistance (Rp) was deduced as 1/Cp [37,40]. The electrochemical parameters are shown in Table 2.…”

“…Also, the linear diagram was recorded, in the potential range close to corrosion potential (± 20 mV) and the polarization resistance (Rp) was calculated. The experimental method and equipment were reported in our previous studies [35][36][37][38][39][40][41].…”

“…Atomic Force Microscopy was performed as in our previous studies [37,40,41], using a non-contact mode atomic force microscopy (NC-AFM, Park Systems, Suwon, Korea), PARK XE-100 SPM system). The cantilever had a nominal length of 125 mm, a nominal force constant of 40 N m -1 , and oscillation frequencies in the range of 275-373 kHz.…”