Icephobic and Anticorrosion Coatings Deposited by Electrospinning on Aluminum Alloys for Aerospace Applications

Abstract

Anti-icing or passive strategies have undergone a remarkable growth in importance as a complement for the de-icing approaches or active methods. As a result, many efforts for developing icephobic surfaces have been mostly dedicated to apply superhydrophobic coatings. Recently, a different type of ice-repellent structure based on slippery liquid-infused porous surfaces (SLIPS) has attracted increasing attention for being a simple and effective passive ice protection in a wide range of application areas, especially for the prevention of ice formation on aircrafts. In this work, the electrospinning technique has been used for the deposition of PVDF-HFP coatings on samples of the aeronautical alloy AA7075 by using a thickness control system based on the identification of the proper combination of process parameters such as the flow rate and applied voltage. In addition, the influence of the experimental conditions on the nanofiber properties is evaluated in terms of surface morphology, wettability, corrosion resistance, and optical transmittance. The experimental results showed an improvement in the micro/nanoscale structure, which optimizes the superhydrophobic and anticorrosive behavior due to the air trapped inside the nanotextured surface. In addition, once the best coating was selected, centrifugal ice adhesion tests (CAT) were carried out for two types of icing conditions (glaze and rime) simulated in an ice wind tunnel (IWT) on both as-deposited and liquid-infused coatings (SLIPs). The liquid-infused coatings showed a low water adhesion (low contact angle hysteresis) and low ice adhesion strength, reducing the ice adhesion four times with respect to PTFE (a well-known low-ice-adhesion material used as a reference).

Novel Design of Superhydrophobic and Anticorrosive PTFE and PAA + β − CD Composite Coating Deposited by Electrospinning, Spin Coating and Electrospraying Techniques

“…Sample thickness was measured by using confocal image microscopy (S1, S2, and S3), where a step function of the cross-section vertical profile at a different location [ 51 ] was employed obtaining the average values. On the S4, a contact profiler was used as it was not possible to obtain an image with the confocal microscope.…”

Comprehensive Measurement of the Adhesion between Ice or Glass and Model PDMS Coatings

“…Various techniques have been employed in the characterization of the icephobic properties of coatings such as the push-off, [25,26] centrifugal, [27,28] blister, [29,30] tensile, [31,32] and zero-degree cone tests. [33,34] Despite the variety of methodologies available, the results from each technique are often reported in a way that makes them difficult or impossible to compare with one another or with independently measured surface energies.…”

Transferrable Electrospinning Nanofiber Meshes as Strongly Adhered Scaffolds for Slippery Liquid-Infused Porous Surfaces

“…SLIPS coatings with electrospinning nanofiber scaffolds use the intended coating target as the electrospinning target, but the deposited nanofiber mesh is only weakly attached onto the substrate. − A one-time convenience that quickly attaches a porous scaffold can lead to unintended detachment of the SLIPS coating during service. During service, even mild agitation can cause the electrospinning nanofibers to detach and expose the surface underneath (Figure S1).…”

“…Variations of SLIPS have utilized different methods for their applications. These include using direct growth of porous material onto the targeted substrates, − deposition of nanomaterials during hydrothermal synthesis, , laser ablation to produce a porous surface, dip coating, spin coating, spray-on, , and electrospinning nanofibers onto the subject. − Of these options, electrospinning is a convenient way to directly deposit continuous nanofibers onto a substrate surface. Afterward, infusion of protective oil into the mesh of electrospinning nanofibers can yield a coating with SLIPS properties.…”