Oil Sorption and Oil-Water Separation Using 3D Printed Sorbents Manufactured with Fused Filament Fabrication

Fiber-based sorbents are widely used and researched for oil spill treatment. The sorption capacity of natural and synthetic fibers ranges from poor to exceptional; however, the preparation of such fiber-based sorbents requires specialized equipment, and the reusability is still unresolved. This paper presents sorbents prepared for the first time by Fused Filament Fabrication 3D printing. The sorbents contain capillaries ranging from 1 to 6 mm that were created by depositing the filament in grid and rectilinear infill patterns. Sorption kinetics and maximum capillary rise were investigated for diesel, and 5W30 and 85W140 oils in the cases of PP, rPET, and PLA as sorbent materials. Capillary size influences sorption capacity and sorption kinetics, 0.7 g/g for 1 mm and 2.7 g/g for 4 mm, whereas at 10 s the relative capillary rise was 64.1% for 1 mm and 86.8% for 4 mm. Viscosity has a significant effect on the sorption kinetics. A special sorbent design is proposed to increase the sorption capacity to 5.26 g/g. Reusability was tested and the sorption capacity stayed constant over 10 cycles. Although the sorption capacity is lower compared to electrospun nanofibers, the oil release does not require any specialty equipment and it takes 7-8 s, making this type of sorbent highly desirable in practical applications.