Corrosion-resistant engineering superhydrophobic and superoleophilic bulk materials with oil-water separation property

A corrosion-resistant superhydrophobic and superoleophilic modified poly(vinylidene fluoride)-based bulk material with oil-water separation ability is fabricated through a facile method of molding and sintering process. Fluorinated ethylene propylene was added as the one of the cross-linking agents. Nanometer silica (SiO2) and carbon nanotubes (CNTs) were added into the bulk material to construct the necessary reticulate papillae structures for superhydrophobic surface. NH4HCO3 was added as a pore-forming reagent in order to realize porous structure and oil-water separation. The bulk material can be designed to different appearances, such as cuboids, cylinder and sealing rings. The resulting bulk material shows excellent superhydrophobic and superoleophilic with a water contact angle of 164A degrees and oil contact angle of almost 0A degrees. As the SiO2 and CNTs filled the entire bulk material, any section of the bulk material shows excellent superhydrophobicity. The thermal resistance of the bulk material was improved due to the introduction of nanoparticles. The corrosion resistance of the superhydrophobic bulk material was investigated in an aqueous NaCl solution (3.5%). The results show that the prepared composite bulk material is effective in corrosion resistance, primarily due to the barrier effect of Cassie-Baxter model of superhydrophobic surface. It is believed that this bulk material would be an engineering material for large-scale application.