Three-dimensional printing-assisted all-in-one surfaces inspired by peristome structures for water–oil separation

Abstract

Water–oil separation membranes with wedge-shaped pores inspired by peristomes were fabricated using a facile and cost-effective manufacturing method. The pattern on the membrane was manufactured through the polymer casting method using the staircase effect of the fused filament fabrication type three-dimensional printer. The oil dropped on the membrane spread along the pattern and entered the hole of the wedge structures, whereas the water droplets passed through the surface. Four different membranes with different wedge pores were fabricated and tested for water–oil separation in an inclined testbed. The membrane with a 40°-wedge structure showed the highest separation efficiency of 98.1% in a 10°-inclined testbed. Furthermore, a membrane with a 30° wedge indicated the most stable separation behavior regardless of the inclination of the testbed, showing the efficiency of 96.9% at 10°-inclined testbed and 96.8% at 20°-inclined testbed. Moreover, different oils were tested for separation experiments using a membrane with a 30°-wedge structure and exhibited sufficiently high separation performance. The water–oil separation membrane can be easily cleaned and reused for various applications such as mixture separation, oil storage tanks, and marine pollution.