Engineering the wetting behavior of ceramic membrane by carbon nanotubes via a chemical vapor deposition technique

Hydrophobic membrane is widely applied for various applications due to its water repellent and self-cleaning properties. In this work, novel alumina/carbon nanotubes (Al2O3/CNTs) composite hydrophobic membranes are prepared in two steps: first, the membranes are fabricated via the phase inversion tape casting method, and then post-treated in a chemical vapor deposition (CVD) process to include CNTs into their structure. The addition of CNTs allows for controlling the contact angle of the membrane from 0 to 136°, creating highly hydrophobic. Moreover, a nitrogen permeability of 0.74±0.01 × 106 L m−2 h−1 bar−1 is achieved of the composite membrane, while its pure water flux is effectively decreased to 0, further indicating the good hydrophobicity. In addition, the hydrophobicity of the membrane can be maintained in the temperature range of 25–200 °C. It is demonstrated that the Al2O3/CNTs composite membrane is a promising hydrophobic membrane candidate for membrane separation application because of its good hydrophobicity, high thermal stability and considerable gas permeability, moreover, the wetting properties of ceramic membrane can be effectively engineered by adding CNTs into the membrane skeleton via the CVD technique.