One-step breaking and separating emulsion by tungsten oxide coated mesh.

Tungsten oxide coated mesh has been fabricated by a simple and inexpensive method. This coated mesh has a dual structure on the surface, consisting of microscale "flower" and nanoscale acicular crystal as the "petal". Combining the micro/nano structure of the surface and the native hydrophilic property of tungsten oxide, the coated mesh shows special wettability: superhydrophilic in air and superoleophobic under water. Because of the special wettability, such a mesh can be used to separate oil/water mixtures as well as emulsions. Attributed to the good water adsorption capacity of tungsten oxide, the abundant grooves of the micro/nanostructure, and the microsized pores of the surface, this coated mesh can accomplish the demulsification process and the separation process in one single-step, and no further post treatment is needed. As an "emulsion breaker and separator", this kind of mesh gives another idea of emulsion separation, which has prospective application in industrial fields such as water treatment and petroleum refining.