Development of durable anticorrosion superhydrophobic electroformed copper tubular structures

Fluidic transportation without any outflow is a challenge in microfluidics, micro heat exchanger and various biomedical micro devices. In this work, an economical manufacturing process is presented to fabricate high aspect microtubes via pulse electroforming process. Further, two-step methodology i.e. chemical etching on electroformed substrate followed by the acid treatment is employed to develop superhydrophobic surface. These superhydrophobic Cu-tubes are characterized via scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy, and drop shape analyzer. Dense and homogeneous petaloid-like structures on the electroformed Cu microtube surface are observed on the exposure of ethanolic stearic acid solution. The water contact angle for prepared superhydrophobic microtube is observed to be 156 ± 1°. The effect of etching time, and steric acid modification time on contact angle and contact angle hysteresis is also studied. The electrochemical investigations of substrates are conducted using a three-electrode system. The superhydrophobic tube shows 82.17 % inhabitation efficiency, enhanced anti-corrosion properties, and having a good protective layer. Visualization experiments are also performed on these tubes which show that the water drops either fully roll down as a water ball or reflected in the same direction when impinging water jet on the tube surface, demonstrating their excellent non-sticking, anti-wettability properties. Thus, durability, anticorrosion properties and under-water stability of superhydrophobic tubular structure along with its manufacturing via pulse electroforming process is demonstrated with this work.