Preparation of electrospun cellulose acetate/polyethylene imine bicomponent nanofibers for CO₂ capture

Bicomponent nanofibers of cellulose acetate (CA) and polyethylene imine were successfully fabricated by electrospinning technique to capture CO2 gas. The concentration of polyethylene imine was fixed to 25, 50, and 75% compared to the CA concentration. The nanofibers were characterized using FT-IR, X-ray diffraction (XRD) and thermogravimetric analyzer (TGA). The effect of PEI on the morphology of CA nanofibers was studied using scanning electron microscope (SEM). The diameter of electrospun CA/PEI nanofibers becomes larger with the increase of PEI content due to repulsion of electrical force from side polar groups. In addition, PEI diffused on the nanofiber surface was observed at high concentrations of PEI. The CO2 adsorption capacity of electrospun CA/PEI nanofiber membranes was investigated at different temperatures using a BET. The increase of PEI content in nanofibers increased the CO2 adsorption capacity, and the adsorption capacity was larger at lower temperature. The decrease in CO2 adsorption capacity with increasing temperature indicates that CO2 adsorption is more responsible for physisorption. Moreover, the CA/PEI electrospun membrane retains 99% of its initial CO2 adsorption capacity after 5 cycles of the adsorption and desorption process.