Electrospun cellulose acetate fibers for the photodecolorization of methylene blue solutions under natural sunlight

Abstract

Cellulose acetate (CA) fibers were obtained by electrospinning and their properties analyzed by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction (XRD), differential scanning calorimeter (DSC) and thermogravimetric analysis. The effect of the polymer concentration on crystallinity and fiber diameter of the obtained material was studied by DSC. The application of the pure polymeric fibers to the discoloration of methylene blue (MB) aqueous solutions in dark and under sunlight irradiation was evaluated with UV–Vis absorption and photoluminescence spectroscopies. Also, the photodegradation of the dye was compared using CA powder and fibers under UV irradiation. The results revealed that the dye molecule discoloration with CA fibers mesh was higher under sunlight irradiation than in dark conditions. The maximum absorption band (664 nm) of MB decreased with the time in the absence and presence of polymer under either solar natural exposition or UV irradiation. The dye organic discoloration efficiency obtained by using electrospun CA mesh was 28% and 98% in dark conditions and under natural solar illumination, respectively. The FTIR showed the interaction of dye organic or sub-products generated with the polymeric component. This work provides a simple method for the discoloration of wastewater effluents using microfibers composed of only one abundant polymeric material, allowing the reduction in the amount of material needed and therefore the manufacturing costs of the adsorbent material.