WETTABILITY TUNING OF CANDLE SOOT COATED 3D-PRINTED MEMBRANES VIA LASER POWER CONTROL

Abstract

Three-dimensional (3D) printing has attracted growing interest for the fabrication of membranes for oil-water separation. While laser power is a key parameter in membrane fabrication, its effect on the wettability of coated membranes is still not well understood, posing challenges for improving membrane performance. This study investigates the effect of laser power on the wettability of 3D-printed polymer membranes coated with candle soot. Membranes were fabricated from virgin polyamide-12 (PA-12) powder using Selective Laser Sintering (SLS) at two laser power settings: 70 W and 80 W and then coated with candle soot. Characterization of membranes involved surface morphology, roughness, water contact angle, mechanical strength and mechanical and chemical stability. Notably, the coated membrane produced at lower laser power of 70 W demonstrated the highest water contact angle (150.7 ± 1.8°), attributed to the lower energy density which led to inefficient powder melting and sintering. In contrast, higher laser power (80 W) produced smoother surfaces and slightly improved tensile strength due to more efficient powder sintering. Mechanical durability remained stable across both settings while chemical stability of the coated membranes showed greater sensitivity to abrasion, likely due to post-printing coating application. These findings underscore the critical importance of optimizing laser power to precisely control membrane characteristics and thereby enhance the efficiency of oil-water separation.