EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

In the present approach the corrosion performance of electrospun core-shell nanofibers designed using electrospinning techniques was evaluated. Electrospinning is a well-established and flexible process which already demonstrated the manufacturing up-scale mass production capability with relatively low costs. It is the most promising and rapid process to generate continuous, ultrafine fibres with uniform morphology, high surface area, high surface roughness and low weight.
Optimization of the electrospinning parameters was done to achieve the formation of beads free nanostructures. Formed nanofibers mats were functionalised by either additive addition into the polymeric solutions before electrospinning step or by immersion into a solution containing various concentrations of nanoparticles. Selection of the used polymer, additives and nanoparticles was done made on their potential for protecting aluminium surfaces against corrosion. Core-shell nanofibers were further combined with a commercially available paint.
Nanostructured materials were placed either directly on the aluminium substrate, either in a sandwiched structure, in between two coating layers with different thicknesses. Substrates were used for the experiments after removing the native oxide (degreasing and pickling). Scanning electron microscopy (SEM) was used to investigate the morphology of the nanostructures. The core-shell nanofibers layer thickness as measured by focused ion beam (FIB) was tailored between 1 and 50 µm. Surface wettability was investigated by means of contact angel measurements. Adhesion of the commercially available coating with and without core-shell nanostructures was measured by performing cross cuts test according to ISO 2409. Coating resistance was investigated by immersion in various solution with the pH ranging from 1 to 13, immersion time vas tailored between 1 to 24 hours. Additionally, electrochemical impedance spectroscopy (EIS) measurements were performed to characterize the effect of incorporating the core-shell nanofibers into the coatings and to evaluate their performance in protecting aluminium against corrosion.