Abstract

Smart coatings that provide corrosion protection on demand have received a lot of recent attention. In the present study, nanofibers containing a corrosion inhibitor were prepared by a coaxial electrospinning technique, which addresses the limitations of inhibitor-loaded microcapsules or nanocontainers. The as-prepared nanofibers have a core-shell structure with Ce(NO3)3 and the chitosan/polyacrylic acid polyelectrolyte coacervate as the core and shell materials, respectively. UV-vis spectroscopic analysis confirms that the nanofibers are pH-sensitive and able to release the enclosed Ce(NO3)3 at both low and high pH conditions, which are spontaneously generated during corrosion at local anodes and cathodes, respectively. A coating system consisting of such nanofibers within a polyvinyl butyral coating matrix exhibits improved corrosion protection of an AA2024-T3 substrate. Moreover, the embedded Ce(NO3)3-loaded nanofibers can persistently release Ce(NO3)3 to impede corrosion of AA2024-T3 when the artificially damaged coating sample is exposed to NaCl solution.

Highlights

  • Aluminum alloys, including AA2024-T3, are strong and light aerospace-grade materials but they suffer from localized corrosion mainly due to the microgalvanic coupling between the intermetallic particles and the aluminum matrix[1]

  • A major benefit of using capsules is to isolate inhibitive species from the polymeric coating matrix, so the adverse interactions can be minimized[9,10]. The shell of these capsules can serve as a diffusion barrier to prevent the uncontrolled release of corrosion inhibitors, avoiding the rapid depletion of inhibitors and ensuring corrosion protection performance for extended periods[11]

  • Due to the presence of interfibrous pores, the intrusion of the coating matrix solution into the nanofiber network can be facilitated, interlocks between the nanofibers and the coating matrix can form to improve the mechanical properties of the coating systems containing nanofibers[17,18]

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Summary

INTRODUCTION

Aluminum alloys, including AA2024-T3, are strong and light aerospace-grade materials but they suffer from localized corrosion mainly due to the microgalvanic coupling between the intermetallic particles and the aluminum matrix[1]. To have a quick demonstration of chains is dependent on the pH of the surrounding medium, so the the dual-pH-sensitivity of the coacervate, bromophenol blue (BB), interactions between the polyelectrolytes can potentially be affected by both acidic and alkaline pH29–31 This assumption an organic dye-loaded coating, i.e., (BB)3/(chitosan/PAA)[5] was fabricated and the release of the entrapped BB at different pH has been validated in prior works where materials made from conditions was studied. For Ce-Fiber-PVB (Fig. 4f and Supplementary Fig. 6c), the than being undermined All these observations suggest Ce-FiberPVB has better corrosion resistance than Fiber-PVB, possibly released Ce(NO3)[3] may have precipitated to form an insoluble film to retard water penetration, so the impedance values of Ce-Fiberoriginated from the corrosion inhibition effect of Ce(NO3)[3].

Li et al 6
METHODS
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