Recently with the development of industries and maritime oil transportation, water pollution due to frequent oil spilling has become a worldwide challenge. So, the fabrication of materials with special wettability and application in oil-water separation has attracted considerable attention. In the present study, a simple one-step method without any chemical modification is reported to fabricate the brass mesh using brass sheet drilling with a commercial nanosecond fiber laser system. Laser ablation creates hierarchical micro/nano structures by plasma created at the irradiated point. The morphology, elemental map and crystal structure of the pristine and drilled brass were analyzed by AFM, FE-SEM, EDS and XRD techniques. Wettability of fabricated brass mesh changes from superhydrophilic to highly hydrophobic (water contact angle 140◦) after laser ablation and exposing to ambient conditions. Also, the obtained highly hydrophobic sample can switches to a superhydrophilic by thermal treatment. Then the superhydrophilic surface can switches again to the highly hydrophobic surface by exposuring to the air for several days. The reasons for wettability switching were discussed in details. The prepared brass mesh with uniform holes can be used as a filter for efficient separation of various organic solvents from water in many cycles without decreasing in its separation capability.
