Fabrication of Ketjen black-high density polyethylene superhydrophobic conductive surfaces

A Ketjen black-high density polyethylene (HDPE) superhydrophobic conductive surface was prepared by a single-step pressing method in which the Ketjen black was pressed into the HDPE leaving it partially exposed to form a superhydrophobic coating with high static water contact angle (～160^o), low sliding angle (～2.5^o), and low sheet resistance (10⁰–10² Ω/sq). The preparation conditions such as the pressing time and the amount of Ketjen black greatly influence the superhydrophobicity and conductivity. The simple pressing of Ketjen black onto the HDPE substrate provides hierarchically structured roughness, leading to the superhydrophobicity of the surface. The superhydrophobic conductive surface also can be obtained with other carbonaceous materials, such as other carbon blacks and nanotubes, and the superhydrophobicity is decided by whether it can produce hierarchically structure roughness.