Controllable Coating Graphene Oxide and Silanes on Cu Particles as Dual Protection for Anticorrosion

Abstract

Although two-dimensional nanosheets like graphene could be ideal atomic coatings to prevent corrosion, it is still controversial whether they are actually effective due to the presence of parasitic effects such as galvanic corrosion. Here, we reported a reduced graphene oxide (RGO) coating strategy to protect sintered Cu metal powders from corrosion by addressing the common galvanic corrosion issue of graphene. A layer of silane molecules, namely, (3-aminopropyl)­triethoxysilane (APTES), is deposited between the surface of Cu particles and the graphene oxide (GO), acting as a primer to enhance adhesion and as an insulating interlayer to prevent the direct contact of the Cu with conductive RGO, mitigating the galvanic corrosion. Due to this core–shell coating, the RGO uniformly distributes in the Cu matrix after sintering, avoiding aggregation of RGO, which takes place in conventional GO-Cu composites. The dual coating of GO and silane results in bulk samples with improved anticorrosion properties, as demonstrated by galvanostatic polarization tests using Tafel analysis. Our development not only provides an efficient synthesis method to controllably coat GO on the surface of Cu but also suggests an alternative strategy to avoid the galvanic corrosion effect of graphene to improve the anticorrosion performance of metal.

Development and Application of Intelligent Coating Technology: A Review

“…Due to the coreshell coating, rGO was uniformly distributed in Cu matrix after sintering, avoiding the aggregation of rGO, that occurs in traditional GO-Cu composite materials. The constant current polarization test by Tafel analysis showed that the dual coating of silane and GO improved the anticorrosion performance of the bulk sample [70].…”

Balanced Anti-Corrosion Action of Reduced Graphene Oxide in Zn-Al Coating during Medium-Term Exposure to NaCl Solution

“…The special protective properties of the Znwt.%G/Al coating produced during medium-term immersion can be attributed to equilibrium effect of G. Actually, graphene is a double-edged sword when applied in corrosion protection of a coating [22]. When G completely coats metal surfaces or is us as an additive in organic or inorganic coatings, G prolongs the propagation path of corrosive medium through its large specific surface area; thus, the use of G in the coat mainly plays a role in shielding protection [31,32]. However, the conductivity of G is clined to expedite the metal degradation when G metal matrix composites are used [1 Due to the potential difference between Zn, Al and G, the reaction process of the Zn-G coating in an aggressive medium involves galvanic reactions.…”

Binder assisted graphene derivatives as lubricants in copper: Improved tribological performance for industrial application

“… 13 , 14 We recently reported a surface modification strategy to controllably coat GO on the surface of Cu particles for anticorrosion application. 15 Simple mechanical mixing is not enough to achieve uniform distribution because of the poor interaction. 16 , 17 …”