Fabrication of single-walled carbon nanotubes from vulcanized scrap rubber via thermal chemical vapor deposition

Abstract

Our previous investigations found that when acrylonitrile butadiene rubber (NBR) was compatibilized with styrene butadiene rubber (SBR) using montmorillonite, the resulting blend exhibited enhanced mechanical strength and heat resistance. However, the enhancement complicates the recycling possibility of the blend at the end of its service period. Pyrolysis of the blend disposal, as a facile recycling route for beneficiation of this material, was elaborated optimally at 450 °C, as specified from thermal gravimetric analysis (TGA), in a horizontal chemical vapor deposition (CVD) pyrolyzer under nitrogen flow to yield hydrocarbon fractions. The CVD process of the resulting hydrocarbons on different catalytic systems was undertaken at 850 °C for 30 min. The investigations carried out using high resolution transmission electron microscopy (HRTEM), thermal gravimetric analysis (TGA) and Raman spectroscopy proved prominent formation of single-walled carbon nanotubes (SWCNTs) in a very efficient yield. It was found that the structure and diameter of produced CNTs were controlled by the crystallinity of the Fe–Ni catalyst supported on different zeolites. Conclusively, the prepared catalyst support played a crucial role in determining both the morphology and yield of the resulting CNTs.