Magnetic carbon nanotubes prepared from LDPE, HDPE and PP Conference Paper uri icon

abstract

  • Plastics are among the most generated solid wastes, predominantly composed by polymers, as low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polypropylene (PP).1 This work deals with the preparation of magnetic carbon nanotubes (CNTs) by catalytic chemical vapor deposition (CCVD) at 850 ºC, considering LDPE, HDPE and PP as carbon precursors representative of urban plastic solid waste in a perspective of circular economy.1 Magnetite supported in alumina nanoparticles previously synthesized by sol-gel were used as catalysts in the CCVD process. Afterward, each synthesized CNT was washed with 50% H2SO4 at 140 °C during 3 h to remove the remaining magnetite, following methods previously described.2 The successful removal of the magnetite particles was assessed measuring the ashes content of the CNTs, removals higher than 83% being achieved (ashes content of final CNT products ranging from 4.2 to 7.9%). The remaining catalyst was located inside the CNTs, conferring magnetic properties to the materials even after washing (Figure 1). BET specific surface areas of 94, 75, and 66 m2 g-1 were found for CNT_LDPE, CNT_HDPE and CNT_PP, respectively, and a slight increase of 1-5 m2 g-1 was observed after washing the materials with acid.
  • This work was financially supported by project "PLASTIC_TO_FUEL&MAT – Upcycling Waste Plastics into Fuel and Carbon Nanomaterials" (PTDC/EQU-EQU/31439/2017), the Associate Laboratory LSRE-LCM (UIDB/50020/2020) - funded by national funds through FCT/MCTES (PIDDAC) and CIMO (UIDB/00690/2020) through FEDER under Program PT2020. Adriano S. Silva acknowledges the national funding by FCT through MIT Portugal Program for the doctoral Grant with reference SFRH/BD/151346/2021. Fernanda F. Roman acknowledges the national funding by FCT and European Social Fund, FSE, through the individual research grant SFRH/BD/143224/2019.

publication date

  • January 1, 2022