Carbon nanotubes prepared from polymer microspheres by spinning and carbonizing

Multi-wall carbon nanotubes (CNTs) with diameters between 10 nm and 20 nm were prepared by melt spinning, stabilizing and carbonizing of fine core/shell-1/shell-2 polymer microspheres. Microspheres were synthesized by three-steps soap free emulsion polymerization of methylmetacrylale (MMA) and acrylonitrile (AN) using potassium persulfate (KPS) as a polymerization radical initiator. The final composition of microspheres was PMMA core/PAN shell-1/PMMA shell-2 and diameter ca. 500nm. The outer PMMA layer played the role of a matrix polymer. Microspheres were directly melt spun at ca. 300°C followed by stabilization of PAN at 220°C in oxygen and carbonization at 100°C in nitrogen. TG-DTA study was used for clarifying the PAN thermal behavior during CNTs synthesis. SEM, TEM and HRTEM were used in characterizing the microspheres and CNTs morphology.