Membrane for Pressure-Driven Separation Prepared with a Method of 3D Printing: Performance in Concentrating Orange Peel Extract

3D-printing enables the fabrication of membranes with desired shapes and geometrical parameters. In this study, a membrane for pressure-driven processes was manufactured in a single step using the fused deposition modeling (FDM) technique. The membrane was produced from a mixture of polylactic acid (PLA) with sucrose as a pore-forming agent. Sucrose was removed from the final membrane by washing it with water. The membrane consists of three layers, and this sandwich-like structure ensures its mechanical stability. The material obtained was characterized using SEM and AFM imaging, as well as nitrogen adsorption-desorption and contact angle measurements. The porosity of each layer of the membrane is due to a loose region, which is coated on both sides with a dense film formed during printing. The pores responsible for rejection capability can be found in grooves between the polymer stripes in the dense layer. The membrane exhibits a water permeability of 64 L m^-2h^-1bar^-1, with a molecular weight cut-off of 69 kDa. The PLA membrane can be used for polyphenol concentration, demonstrating a permeability of 2-3.4 L m^-2h^-1bar^-1 and a selectivity towards these compounds of 78-98% at 0.5 bar, with a flux decline ratio of up to 50%.