Hybrid nanocarbon materials such as carbon nanotubes (CNTs) coated by diamond nano-crystals (DNC) in a conformal manner are scientifically and technologically attractive because of the potential possibility of combining the excellent structural, thermal, mechanical, chemical, optical and electronic properties of both carbon allotropes. It has been speculated that the combination of CNT and DNC could give rise to materials with novel properties that could be used in a wide range of applications such as functional composite materials, field emission and other electronic devices, biodevices, wear-resistant coatings, thermal management of integrated circuits, electrical field shielding and micro- and nano-electromechanical systems (MEMS/ NEMS).
NANOCARBON has researched on a new coating pathway to obtain CNTs coated with diamond and SiC nano-crystals with high conformal degree at low CNT and substrate temperature, below 200 °C. This is much below the conventional temperature range of 650-900 °C.
The synthesis of such hybrid nanocarbon material is achieved, via the exposure of CNTs dispersed on a substrate maintained at a temperature below 200 °C, solid carbon and silicon sources to pure H2 activated by HFCVD. During such process, the structure of the MWCNTs is preserved and the coating is highly conformal. The average size of the grains is below 10 nm.
The hybrid nanocarbon material elaborated from this method may be further investigated to be used in functional and thermo-resistant composite materials and as stable emitters in field emission devices.
Carbon Nanotubes Coated with Diamond Nanocrystals and Silicon Carbide by Hot-filament Chemical Vapor Deposition below 200° C substrate temperature, F.Piazza, G. Morell, J. Beltran Huarac, G. Paredes, M. Ahmadi, M. Guinel, Carbon 75, 113 (2014).
Carbon nanotubes conformally coated with diamond nanocrystals or silicon carbide, methods of making the same and methods of their use, Fabrice Piazza, United States Patent # 9,458,017.