Nanocápsulas de guaraná como aditivo na eletrodeposição de zinco para proteção contra corrosão,

Abstract

Metal corrosion is one of the main challenges faced by the industry, resulting in high economic costs and significant environmental impacts. In this context, this study investigated the use of nanoencapsulated particles of guaraná seed extract (Paullinia cupana) as an additive in zinc electrodeposition processes to enhance corrosion resistance. Guaraná, a plant native to the Amazon, is known for its richness in bioactive compounds, such as caffeine, theobromine, catechins, tannins, and flavonoids—substances with antioxidant properties. These compounds were encapsulated in polymeric matrices using optimized methods to improve their chemical stability and controlled release. The incorporation of these nanocapsules into the electrolytic bath showed potential for reducing the formation of defects in the metallic coating and increasing its compactness, contributing to more efficient protection against corrosive agents. Furthermore, gravimetric and electrochemical analyses confirmed that the use of guaraná nanocapsules significantly reduced the corrosion rate in SAE 1020 carbon steel substrates coated with zinc. Complementary studies indicated that the protection mechanism is related to guaraná's ability to act as a physical and antioxidant barrier, minimizing corrosive attack in a 0.5 mol/L NaCl solution simulating a highly corrosive environment. The study also explored the sustainable impact of this approach, highlighting the feasibility of using renewable and biodegradable resources as an alternative to traditional synthetic additives. These findings reinforce the potential of nanoencapsulated guaraná as an innovative and sustainable corrosion inhibitor, with promising applications in industrial sectors