3D-printed surface-patterned ceramic membrane with enhanced performance in crossflow filtration

Appropriate surface patterns on polymer membranes have been demonstrated to have a strong effect on improving the permeability and anti-fouling ability. Herein, for the first time we have developed a surface-patterned alumina ceramic membrane with gradient porous structure using a novel 3D-printing technology. The well-controllable surface-patterned alumina membrane was fabricated by use of 3D-printable ceramic ink through a layer-by-layer coating on a porous substrate, after which the designed patterns were made on the membrane surface by 3D printing the same ink. The 3D-printed line-patterned membrane showed a notable increase in steady flux and a significantly enhanced antifouling ability, especially when the printed lines were perpendicular to the feed flow direction, as evaluated by our experimental and computational fluid dynamics simulation results. Fouling mechanisms were similar between different feed flow directions and evolved from the pore constriction or intermediate pore blocking towards cake filtration. The distance and height of the 3D-printed lines was also revealed to have influences on the fouling performance. Together with the advantages of easily designed structures and a rapid design-to-fabrication process using 3D-printing technology, this study provides an effective new approach to fabricate the advanced ceramic membranes with fouling mitigation for wastewater treatment.