Enhancing the material properties of recycled poly(ethylene terephthalate) nanofibers through carbon nanotube and carbon nanotube:graphene incorporation

In this study, a carbon nanotube:multilayer graphene (CNT:G) hybrid nanofiller was constructed and recycled poly(ethylene terephthalate) (rPET) based composite nanofibers containing CNT, or CNT:G were electrospun and characterized in order to fabricate thermally conductive polymer nanomats. Particular attention was directed toward investigating the effects of CNT and CNT:G in enhancing thermal stability, thermal conductivity coefficient, and heat dissipation efficiency of the composite nanofibers. The thermal conductivity coefficient of neat rPET nanofibers was found as 12.753 W/mK while it increased to 34.437, 38.713, and 96.957 W/mK with 0.25%, 1%, and 5% of CNT incorporation, respectively. When hybrid nanofillers were used at a loading of 1%, the thermal conductivity coefficients for rPET/CNT:G nanofibers with CNT:G ratios of 1:1 and 1:3 respectively increased to 62.229, and 47.62 W/mK. The heat dissipation efficiency of the rPET nanofibers was also enhanced upon nanofiller incorporation which was illustrated with infrared thermography data. The results suggest the use of both CNT- and CNT:G-loaded rPET composite nanofibers as promising textile materials for passive cooling applications. Highlights: Hybrid CNT:G nanofillers are synthesized with weight ratios of 1:1 and 1:3. rPET/CNT and rPET/CNT:G composite nanofibers are electrospun. The thermal conductivity coefficients of the composite nanofibers are improved. The composite nanofibers are also mechanically enhanced. Value-added rPET products as thermal management materials are proposed.