Effect of wire and needle spinning on the direct manufacturing PAN/amine nanofibrous membranes for CO ₂ sorption

Manufacturing of membranes for carbon dioxide (CO ₂ ) capture is a significant research topic. Achieving maximum CO ₂ sorption capacity while maintaining air permeability with a minimum number of technological steps was the main motivation of this work. The greatest advantages of this approach are its simplicity, low cost and easy transition to industrial scale. Electrospun nanofibrous membranes polyacrylonitrile (PAN)/triethylenetetramine (TETA) and polyacrylonitrile (PAN)/tetraethylenepentamine (TEPA) were prepared by one-step technology (modifying amines TETA, TEPA in different weight concentrations dissolved directly in spinning solution) using two different spinning conditions: needle spinning (electric field attached to a hollow needle through which a polymer solution is extruded under pressure) and wire spinning (electric field connected to a thin wire that is coated with a layer of polymer solution, and the spinning thus takes place from the free surface). Wire electrospinning turns out to be more suitable for a one-step technology with a modifying substance in the spinning solution. The best result as to the CO ₂ sorption capacity has been obtained for wire spinning PAN_TEPA_2% 11.7 ± 1.3 cm ³ /g with air permeability 53 ± 5 L/m ² /s, which gives a good chance for the design of a sandwich functional unit for practical use. In addition to studies of CO ₂ adsorption, the article also deals with the comparison of both spinning methods for the PAN polymer, which have not yet been compared for this polymer in the literature, not only from the point of view of the possibility of preparing PAN nanofibers, but also their functional use precisely for CO ₂ capture.