In the study, a conductive polypyrrole (PPy) is deposited on the lamellar sericite powder (SCP) surfaces by an in situ oxidization growth method and the prepared PPy/SCP conductive additive is successfully applied on the zinc-rich primer (ZRP) coating. The equal mass substitution and the equal volume substitution methods of the conductive additives to zinc dusts are discussed, as well as the optimal replacing ratio to achieve the best corrosion protection effect of the ZRP coatings. The results indicate that the equal volume substitution method is in favor of corrosion resistance of coating film. The salt spray test and the electrochemical impedance spectroscopy (EIS) and polarization curves show that the prepared ZRP coating with a 66% zinc content and replacing ratio of 1:3 possesses the best corrosion-resistant performance and an optimal adhesion strength. The replacement of PPy/SCP particles to zinc dusts using the equal volume substitution method is feasible to achieve the improvement in anticorrosion ability through a synergic function of the cathodic protection effect and barrier effect.
Zinc-rich primers are among the most promising organic coating systems for improving the corrosion resistance of metals in the marine environment. However, the high zinc content results in poor coating adhesion, high cost, insecurity and pollution. To decrease the zinc dust content, the carbonaceous and polymer conductive additives carbon black (CB), conductive graphite (CG), multiwalled carbon nanotubes (MWCNT) and polyaniline (PANI) were introduced to partially replace the zinc dust in the primers. A comparative study of the anticorrosion performance of epoxy zinc-rich primer (ZRP) is presented herein to systematically discuss and elaborate on the effects of the different conductive additives. There were no blisters, rust or corrosion products presented on the coatings of the CB-modified series due to the good dispersion and conductivity of nanosized CB clusters, while the zinc corrosion products covered the surface of the MWCNT-modified series samples, which was attributed to the excessive electrical conductivity resulting in high consumption of zinc powder. The lamellar CG provided an additional blocking barrier for the coatings based on the maze effect. The transition from the intrinsic state to the doped state of PANI resulted in corrosion protection for the coatings depending on the cathodic and barrier function. The experimental results suggested that the formula with 2 wt.% CB and 67 wt.% zinc dust had the most promising anticorrosion properties, which was also demonstrated by the high Rct and low CPEdl values calculated according to the equivalent electrical circuit analyses.
Based on the operational data of the circulating water system in a thermal power plant, BP neural network and support vector machine regression were used to establish the prediction model of circulation water system evaporation and wind blow loss. The trail method was used to improve the BP neural network prediction model, and for the prediction model of support vector machine regression, the kernel function and the corresponding parameters were selected through optimization. The results showed that the mean square error of the simulation results of the two models were 0.071 and 0.070 respectively in summer and 0.046 and 0.047 respectively in winter, this meets the prediction requirements of project and demonstrates high prediction accuracy. With the evaluation index of neural network model, the simulation and prediction results of the two models were compared and analysed. The results showed that the simulation results of two model were basically the same, but the support vector machine model training sample time is shorter, the convergence speed is faster, and the overall network model performance is better.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.