Naturally produced carbon nanotubes
C. Velasco-Santosa, b, A. L. Martínez-Hernándeza, b, A. Consultchic, R. Rodrígueza and V. M. Castaño, , a
a Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autonama de Mexico, A.P. 1-1010, Santiago de Querétaro, Querétaro 76000, Mexicob Universidad Autónoma de Querétaro, Campus Cerro de las Campanas, Querétaro, Querétaro 76010, Mexicoc Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas, No. 152, Mexico DF 07730, Mexico Received 30 January 2003; revised 3 April 2003. Available online 30 April 2003.
Carbon nanotubes represent an impressive kind of materials with diverse unexpected properties, and different methods to artificially produce them have been developed. Recently, they have also been synthesized at low temperatures, demonstrating that these materials might exist in fluids or carbon rocks of the Earth’s crust. A new type of natural encapsulated carbon nanotubes found in a coal–petroleum mix is presented. These findings show that all allotropic carbon forms known up to date can be produced in Nature, where pressure, catalysts particles, shear stress and parameters other than exclusively very high temperature, seem to play an important role for producing nanotubes.
Fonte:
Chemical Physics Letters
Volume 373, Issues 3-4 , 20 May 2003, Pages 272-276
