Protective effect of poly(4-Vinylpyridine) containing surface films to the corrosion of copper

Abstract

Neste trabalho investigou-se a capacidade de filmes de poli(4-vinilpiridina) (P4VP) em melhorar as propriedades de corrosão do cobre em H 2 SO 4 0,1 mol L -1 . Filmes que formam o complexo macromolecular Cu(P4VP) 2 (SCN) 2 foram obtidos por métodos eletroquímicos ou espontaneamente (por imersão) em soluções contendo 3% de ácido acético, KSCN 0,1 mol L -1 e P4VP. As características morfológicas dos filmes e o seu efeito sobre a corrosão do cobre foram analisados por técnicas de microscopia e eletroquímicas, respectivamente. Um aumento acentuado na resistência à corrosão de amostras de cobre recobertas por filmes de P4VP gerados espontaneamente foi observado em comparação às amostras não recobertas. A melhor condição para a obtenção destes filmes consiste na imersão do cobre em soluções contendo P4VP 0,1 mol L -1 durante 3 -4 h. Empregando-se esta metodologia, registraram-se eficiências de inibição (EI) de 94 -98%. Para filmes gerados eletroquimicamente, a EI foi de 70 -85%.We report here on the ability of poly(4-vinylpyridine) (P4VP) films to improve the copper corrosion properties in 0.1 mol L -1 H 2 SO 4 . Films formed by Cu(P4VP) 2 (SCN) 2 macromecularcomplex were electrochemically or spontaneously (by immersion) grown onto copper surfaces in 3% acetic acid, 0.1 mol L -1 KSCN and P4VP containing solutions. Imaging and electrochemical techniques were employed to characterize the film morphology and evaluate its effect on the copper corrosion, respectively. A substantial increase in corrosion resistance of copper samples spontaneously coated by P4VP films was found in comparison to the uncoated ones. The optimum conditions for spontaneous growth comprise a 3 -4 h immersion period in a 0.1 mol L -1 P4VP containing solution. Inhibition efficiencies (IE) of 94 -98% were recorded by employing this methodology. For electrochemically grown P4VP films, the IE was 70 -85%. Keywords: poly(4-vinylpyridine), corrosion, copper IntroductionThe use of d-block metals to produce coordination complexes in polymer blends has been studied over the past few decades. 1 By physically mixing transition-metals cations and coordinating polymers, it has been possible to obtain materials with properties different from those of the individual bulk components. 2,3 Recently, the importance of developing macromolecular complexes was highlighted because of their optical, magnetic, electronic and solution properties. 4 For instance, the conducting and thermal properties of poly(4-vinylpyridine) (P4VP) are significantly changed when the polymer is complexed with copper ions. 5 The technological applications of the P4VP/ copper system include reactive blending, 6 catalyst, 7-9 cation exchange resins and membranes designed to preconcentrate metals from dilute solutions 10 or remove them from wastewater, 11 solid-state electrochemical cells, 12 circuit manufacturing on microscopic smoothly polymeric surfaces 13 and anti-corrosion methods. 14 Poly(4-vinylpyridine)/cupric salts complexes can be synthesized by physical mixing methods, and their therma...

Robust Electroreduction of CO2 at a Poly(4‐vinylpyridine)–Copper Electrode

“…Finally, voltammetric analysis of P4VP/Cu and Cu electrodes (Figure S5) reveals that copper–P4VP complexes are formed through anodic corrosion of copper electrodes at −0.3–0 V, which is in agreement with an earlier report . This explains the appearance of copper at the polymer surface after soaking the freshly deposited P4VP/Cu electrode in 0.1 m KHCO 3 .…”

“…Once formed, the Cu–P4VP complexes partially inhibit further corrosion of the copper support. The inhibition effect can be related to the higher rigidity and reduced permeability of the metal cross‐linked polymer, which has already been employed to protect copper electrodes from anodic corrosion . The barrier properties of Cu–P4VP complexes also explain the observed prevalence (ca.…”

“…In P4VP complexes with copper, the copper cations can coordinate with several pyridyl groups, including groups from different polymer chains, which increases the rigidity and insolubility of the polymer matrix . Coordination to metals induces cross‐linking of the polymer, leading to its semiconducting‐to‐metallic conductivity and anticorrosion properties …”

Adsorption behavior of caffeine as a green corrosion inhibitor for copper

“…Chromate, molybdate and tetraborate have been cited as inorganic corrosion inhibitors. More recently, short-chain alkanoic acid potassium salts [9], poly(4-vinylpyridine) [10][11][12] and poly(4-vinylpyrrolidone) [13] have also been shown to be potential corrosion inhibitors for copper.…”

Interaction of poly(4-vinylpyridine) with copper surfaces: electrochemical, thermal and spectroscopic studies

“…We have observed a dark green film resulting from the interaction of P4VP and copper surfaces when the working solution contained potassium thiocyanate in either open circuit potential conditions (spontaneous film growth) or not (electrochemically generate copper ions). 15 The goal of this work is to explore the electrochemical formation of this film as well as its thermal behavior, composition and structure characteristics.…”