  The separation of liquid mixture has been studied for a long time. Separation
proceeds based on the difference in physical properties including pore size and
electrostatic interaction. Therefore, there are many difficulties in separation
of materials having similar size or polarities in physical properties such as
ethanol-water and 1,4-dioxane-water mixtures. While we still lack a universal
generalization of these ideas to the separation, pervaporation based on a
difference in transport rates by permeability through a membrane by the
permeate was early suggested. Yet there is an existing technical gap to remove
trace amounts of organics dissolved in water. Here, we report a novel
separation strategy employing a metamaterial, called meta-separation using the
exotic structural property of metamateirals rather than electrostatic
characteristics. The structural properties of metamaterials provide various
functions of super-hydrophobicity based on roughness of surface, the strong
capillary effect based on nanopore, and huge void for great absorption of
organics. It exhibited a water contact angle of 151.3{\deg} and high adhesive
property from nanopore. On the other hands, ethanol was immediately absorbed up
to 93 wt%. This differences made it possible to quickly and easily eliminate
organics dissolved in water. Furthermore, their applications are expected to
achieve functions in environmental remediation, biofuel separation process,
etc., without large scale facilities.
