Anti-corrosion property of zinc: Nanotubes vs nanoparticles
Poly N-(vinyl) pyrrole (PNVPY) nanotubes (NTs) and nanoparticles (NPs) were prepared via a UV-catalysed green chemical oxidative method in the presence of cetyltrimethylammonium bromide (CTAB) and polyvinyl pyrrolidone (PVP) as soft templates, respectively.
The chemical structure of the PNVPY nanostructures was characterised by FTIR spectroscopy, UV–vis absorption spectra and 1H-NMR spectroscopy. The morphologies of PNVPY nanostructures were observed by the scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
It was indicated that PNVPY NTs had an outer diameter less than 200 nm and a length in microscale. PNVPY NPs had an average diameter of 30 nm. Moreover, a series of anti-corrosion coatings on zinc were prepared by blending nanostructured PNVPY and carbon black with polyvinyl butyral (PVB) matrix to investigate the effect of the morphologies of PNVPY nanostructures on the corrosion protection ability. The surface and cross-sectional morphologies of the anti-corrosion coatings were observed by optical microscopy and SEM.
Better anti-corrosion performance
Open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarisation measurements showed that PNVPY NPs with a larger surface area and a smaller scale yield a better anti-corrosion performance than PNVPY NTs in the coatings. The probable anti-corrosion mechanism of these anti-corrosion coatings was proposed.
The study has been published in Progress in Organic Coatings, Volume 136.
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