Superhydrophobic and superhydrophilic properties of laser-ablated plane and curved surfaces

We examine the hydrophobic and hydrophilic properties of the plane and curved surfaces of different materials ablated using 5 ns laser pulses in air. The difference in the contact angles between liquid and surface of the modified graphite and AlNiCo alloy rods using different fluencies of the ablating pulses are demonstrated. The wetting contact angle of ablated graphite rod was found to be 147 degrees, i.e., the modified curved surfaces demonstrated the superhydrophobic properties. On the other hand, the superhydrophilic properties, with 7 degrees wetting contact angle, were demonstrated in the case of ablated aluminum alloy. A schematic model was proposed for the application of the graphite rod as a membrane for the oil-water separation.