Morphological, Thermal, and Mechanical Properties of Electrospun Recycled Poly(ethylene terephthalate)/Graphene Oxide Composite Nanofiber Membranes

Abstract

This study investigates the influence of graphene oxide (GO) on the properties of electrospun recycled poly(ethylene terephthalate) (rPET) composite nanofiber membranes. GO nanosheet layers, with good hydrophilic properties, were incorporated at various loadings (0-8 wt %) during electrospinning. The surface morphological analysis revealed that GO loadings of less than 0.5 wt % lead to smoother fiber surfaces due to less agglomeration, as shown by the scanning electron microscope images. The smooth fiber surface shows that the nanosheets are intact within the rPET polymer matrix at low GO loadings. The differential scanning calorimetry results reveal that nucleation increases linearly with GO content as observed by the change in crystallization peak temperature (Tc) of rPET from 184 to 200 °C. Both the Tc and characteristic rPET crystallization peak in the X-ray diffraction pattern indicate the presence of a physical interaction between the GO sheets and the rPET polymer matrix. A decrease of up to 10° in the water contact angle at 0.5 wt % GO loading; beyond this, it starts to increase due to the agglomeration of GO sheets. From this study, it is preferable to maintain the GO content to a maximum of 0.5 wt % to maximize hydrophilicity. This has the implication of enhanced filtration permeation flux in applications where hydrophilic membranes are desired.