This research presents the synthesis of nanoparticles of ZnO (Nps-ZnO) obtained by two methods: chemical precipitation (method 1) and combustion in solution (method 2). The effect of each method on the crystallographic properties of Nps-ZnO is studied. The Nps-ZnO obtained present, according to EDS analysis, an atomic Zn: O ratio of 0.95 and 1.36 when two methods were used respectively. The formation of Nps-ZnO with Wurtzite-type hexagonal arrangement is confirmed with XRD analysis. XRD results show there is not a big difference between the lattice parameters and interplanar spacing for the samples obtained by the two synthesis methods. However, the Nps-ZnO obtained by chemical precipitation show higher values of dislocation density (1.780 × 10− 3) nm− 2 than those obtained by combustion in solution (0.152 × 10− 3) nm− 2. A similar behavior is observed with the ...

Hydrolysable tannins are natural polyphenols susceptible to hydrolysis that can be extracted from different vegetable plants. Tara pods, of Peruvian origin, concentrate a high tannin content and, besides their low exploitation impact, their tannin extract has shown high potential industrial applications due to their ability to form complexes with a broad variety of metal ions. However, developing an anticorrosive pigment of low-cost, high efficiency and reduced environmental impact is still a challenge. Herein, tannin-rich pigments were synthesized with Tara powder and zinc ions to produce metallic complexes known as tannates for corrosion protection. The anticorrosive behavior of zinc tannates was studied by direct current electrochemical techniques on pigment extracts and electrochemical impedance spectroscopy tests by analyzing pigmented primers and painting systems. Scanning electron...