Development of a novel method to synthesize carbon nanotubes from granulated polystyrene and nickel nanoparticles by microwave heating

In this work, we describe a novel "nickel nanoparticle method" for synthesis of carbon nanotubes (CNTs). We could readily synthesize CNTs from commercially available granulated polystyrene (PS) and nickel nanoparticles in a very short time by using a domestic microwave oven remodeled to control the temperature. In order to establish the best conditions for the synthesis of CNTs, we carried out the syntheses with changing temperature and/or time of microwave heating, and then the qualities of the resulting CNTs were checked by TEM, Raman spectroscopy and X-ray diffraction. As a result, it was clarified that the best condition was at 800 [degree]C for 10 min. Under this condition, we could easily synthesize CNTs in gram scale at a time, when the total amount of the mixture of PS and nickel nanoperticles increased to several grams with keeping the nickel weight ratio at 0.30. This may lead us to a bright prospect of rapid synthesis of large amounts of CNTs in kilogram scale by using a large-scale reactor in a factory.