3D-printed, flow-through water filters for microplastic capture: The effect of surface porosity, column height, and pressure-sensitive adhesives on removal efficiency

Growing concern over microplastic pollution in the environment has led to an increase in exploration over how to prevent them from entering the environment, as well as the food and water we consume. Fused deposition modeling (FDM) or three-dimensional (3D) extrusion printing offers an easy, scalable, and customizable approach to the generation of customized and innovative material designs, including filtration systems to combat microplastics. In this work, we report a tortuous, layer-based, 3D printed, flow-through filtration column for the easy capture of microplastics from wastewater. Through the addition of polyethylene glycol (PEG) as a sacrificial additive to polylactic acid (PLA), the printed filters can be etched using hot water to achieve a micro- and nano-porous surface with better microplastic capturing capabilities. Further improvement was made via the deposition of pressure-sensitive adhesives, polydopamine (PDA) and poly (2-ethylhexyl acrylate), to improve physical non-covalent interactions with the microplastics on the surface. Finally, through analysis of the filtration column height, a high-efficiency filter capable of 90% microplastic removal was achieved. This work highlights the possibility of using simple, inexpensive, customization, and efficient flow-through filtration systems for high-efficiency microplastic capture from drinking water.