New Electrospun Polystyrene/Al2O3 Nanocomposite Superhydrophobic Coatings; Synthesis, Characterization, and Application

Ahmed Bahgat Radwan,Mariam Al-Maadeed,Adel Mohamed,Aboubakr Abdullah

doi:10.3390/coatings8020065

Ahmed Bahgat Radwan, Mariam Al-Maadeed + Show 2 more

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https://doi.org/10.3390/coatings8020065

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Abstract

The effect of electrospinning operational parameters on the morphology, surface roughness, and wettability of different compositions of electrospun polystyrene (PS)–aluminum oxide (Al2O3) nanocomposite coatings was investigated using different techniques. For example, a scanning electron microscope (SEM) coupled with an energy dispersive X-ray (EDX) unit, a Fourier transform infrared (FTIR) spectrometer, an atomic force microscope (AFM), and water contact angle (WCA), and contact angle hysteresis (CAH) measurements using the sessile droplet method, were used. The latter used 4 µL of distilled water at room temperature. PS/Al2O3 nanocomposite coatings exhibited different morphologies, such as beaded fibers and microfibers, depending on the concentration ratio between the PS and Al2O3 nanoparticles and the operational parameters of the electrospinning process. The optimum conditions to produce a nanocomposite coating with the highest roughness and superhydrophobic properties (155° ± 1.9° for WCA and 3° ± 4.2° for CAH) are 2.5 and 0.25 wt % of PS and Al2O3, respectively, 25 kV for the applied potential and 1.5 mL·h−1 for the solution flow rate at 35 °C. The corrosion resistance of the as-prepared coatings was investigated using the electrochemical impedance spectroscopy (EIS) technique. The results have revealed that the highly porous superhydrophobic nanocomposite coatings (SHCs) possess a superior corrosion resistance that is higher than the uncoated Al alloy by three orders of magnitude.

Highlights

Superhydrophobic surfaces with low sliding angle (SA ≤ 10◦ ) and high water contact angle (WCA ≥ 150◦ ) exhibit a low resistance to water mobility on the surface as a result of the embedded air in the composite under the water on these surfaces [1,2]
The representative scanning electron microscope (SEM) micrographs of the electrospun PS with different concentrations of Al2 O3 nanoparticles are shown in Figures 1 and 2, respectively
Different morphologies of PS in absence and presence of Al2 O3 nanoparticles including beaded fibers and free beads are obtained by varying the concentration of PS and Al2 O3 and/or the operational parameters of the electrospinning process

Summary

Introduction

Superhydrophobic surfaces with low sliding angle (SA ≤ 10◦ ) and high water contact angle (WCA ≥ 150◦ ) exhibit a low resistance to water mobility on the surface as a result of the embedded air in the composite under the water on these surfaces [1,2] Such surfaces have attracted a significant interest because of their potential applications in many industrial fields and biological processes, e.g., highly corrosion resistant [3] and anti-adhesive coatings [4], self-cleaning materials [5], antifingerprint optical devices [6], printing technologies [7], water–oil separation [8], and digital microfluidics [9]. The properties of these solutions, such as the surface tension, the viscosity, and the molecular weight of the polymer, in addition to the electrospinning parameters, e.g., the distance between a needle and a substrate, the solution flow rate, and the applied voltage, are the main factors that influence the electrospinning process that affects the properties of the produced fibers

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