Corrosion protection performance of nanoparticle incorporated epoxy paint assessed by linear polarization and electrochemical impedance spectroscopy

Abstract

Epoxy paint was homogeneously incorporated with Al2O3(α), Fe2O3(α), SiO2, and ZnO nanoparticles at 1, 2, and 3 wt% with respect to total weight of hardener and undried epoxy, and coated on carbon steel coupons. Corrosion protection performance of the samples was evaluated by linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) in 3 wt% NaCl solution. Analysis of LSV data and thorough analysis of EIS data showed the beneficial effect of all types of nanoparticles at 1 wt%. For 2 and 3 wt% samples, performance was different, depending on the nanoparticle type. However, the sample containing 3 wt% Al2O3(α) showed the best performance among all the tested samples. The results were correlated to the ability of the nanoparticles to block corroding coatings by decreasing the porosity of the dried epoxy paint.

Atomic Layer Deposited TiO2 and Al2O3 Thin Films as Coatings for Aluminum Food Packaging Application

“…Examination of Figure 4 shows that all films are very effective in terms of increasing impedance of the Al substrate. The samples show capacitive arc characteristic that indicates corrosion protection, although some samples also present resistive characteristic in the region of high frequencies, which is attributed to non-ideality of the coatings in complete blocking the corroding species (such as water, oxygen, and ions) [ 36 ]. Concern the capacitive arc diameter, the resin-coated sample increased by approximately 11 times the diameter in comparison with bare Al, indicating the ability of the resin to protect the aluminum in contact with the beer electrolyte.…”

“…Bode magnitude plot represents the ratio of the amplitude of alternating voltage to alternating current versus frequency, irrespective of their phase shift. On the other hand, the Bode phase plot represents the phase difference between alternating voltage and alternating current versus frequency, irrespective of their amplitudes [ 36 ]. Both plots contain information which is not directly extractable from Nyquist plots.…”

“…A characteristic of Bode phase plot is its ability to identify the predominant electrical behavior of the system in a given frequency range. For example, capacitive, resistive and mixed capacitive-resistive behavior appear as −90, 0, and 0 to −90 degrees lines, respectively [ 36 ]. Bode phase plots in Figure 5 b shows completely different behavior for samples coated and uncoated.…”

“…The LSV tests were performed in voltage range of −0.65 to −0.35 V at scan rate of 1 mV s −1 . The corrosion current ( i corr ) and corrosion potential ( V corr ) were obtained from LSV and Tafel plots; i corr was the current obtained from intercept of tangent lines on cathodic and anodic branches of Tafel plots at V corr [ 36 ]. The potential corresponding to zero current (current transition from cathodic to anodic) was assigned as V corr .…”

Corrosion prevention prospects of polymeric nanocomposites: A review

“…99 It is also important to understand the anti-corrosion mechanism and adhesion properties offered by a particular nanocomposite. 100,101 Adsorption energies of corrosion inhibitors need to be studied using thermodynamics and molecular dynamic simulations. Efforts are also needed to scrutinize the association between the structure and corresponding inhibition efficiency of polymer nanocomposites.…”