Double-layer with electroactive and superhydrophobicity based on polymer nanotubes to improve robustness and anti-corrosion performances

The phenomena of corrosion in metals have resulted in significant damage to the day-to-day lives of humans, the routine maintenance of engineering metal materials, and catastrophic corrosion damage has also triggered huge economic losses. Herein, we propose a double-layer PDVB/FSiO2-PDVB@PPy/EP sprayable coating with excellent robust superhydrophobicity and electroactive based on mass-producible polydivinylbenzene nanotubes (PDVB NTs) to apply in anti-corrosion of Q235 steel plate. On one hand, the electroactive base layer of PDVB@PPy/EP can constitute a physical barrier against corrosive media; On the other hand, cross-linked PDVB NTs containing FSiO2 NPs (PDVB/FSiO2 NTs) can form a superhydrophobic surface structure to avoid substrate corrosion from corrosive liquid. The water contact angle (WCA) of the composite coating is 163.9° and the sliding angle (SA) is 3.6°, indicating that the coating possesses excellent superhydrophobic properties. Remarkably, Cross-cut scratch, tape peel, and Taber abrasion tests confirm that the composite coating exhibits excellent robust performance. The pitting pit depth after 30 days of salt spray test is 4 μm, and following 60 days of immersion in a solution containing 3.5 wt% NaCl, the protection efficiency (P.E.%) reaches 94.79 %. These results suggest that the double-layer electroactive superhydrophobic coating exhibits excellent corrosion resistance.