Galvanic function of zinc-rich coatings facilitated by percolating structure of the carbon nanotubes. Part I: Characterization of the nano-size particles

Abstract

The newly developed zinc-rich hybrid paints are composed of polypyrrole (PPy) and polystyrene-sulfonate (PSS) modified alumina hydrate and either purified or functionalized multi-walled carbon nanotubes (MWCNTs). Preparation of the nano-size particles, i.e., in situ polymerization and deposition of PPy-PSS complexes on the mixture of alumina hydrate and MWCNTs is presented. Characterization of the particles by cyclic voltammetry (CV), Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) as well as their dispersions by rheology investigation is detailed in this part of the work. High electrochemical reversibility, increasing electrical conductivity and Coulombic efficiency of the particles with greater relative amount of the MWCNTs were evinced. Thin layer polymer deposition was found continuous on alumina and the MWCNTs and varied compactness of the PPy films and charge-delocalization over their network were witnessed depending on the proportion of incorporated PSS. Different micron-scale dispersity of the particles, compactness and ramification of particle clusters as well as their aggregation at nano-scale and flocculation at micron-scale were disclosed resulting in either kinetically three-dimensional (3D) interacting or non-percolating distribution. Corrosion protection performance of the hybrid coatings was examined whereas characteristics of the protection mechanism is substantially analysed from many perspectives, which all detailed in 2nd part of this study.