The present invention relates to entangled-type carbon nanotubes which have a bulk density of 31 kg/m.sup.3 to 85 kg/m.sup.3 and a ratio of tapped bulk density to bulk density of 1.37 to 2.05, and a method for preparing the entangled-type carbon nanotubes.

The present disclosure provides a method for producing elongated non-entangled nanotube filaments using a vertical upward flow floating catalyst chemical vapor deposition system.

The present disclosure provides a method for producing elongated non-entangled nanotube filaments using a vertical upward flow floating catalyst chemical vapor deposition system.

The invention discloses a carbon-based composite material and its preparation method and application, which belongs to the technical field of carbon material preparation. The carbon-based composite material comprises the substrate, carbon film and structural carbon which are integrated into one body. The electron, ion and atom transmission and chemical structure characteristics of the carbon-based composite materials are modified by the carbon film and structural carbon containing alkali and/or alkali earth elements resulting in the carbon-based composite materials having excellent physical and chemical properties, which can be used for various applications including battery electrodes, capacitor electrodes, various sensors, solar cell electrodes, electrolytic water hydrogen production electrodes, hydrogen storage materials, catalysts and catalyst carriers, composite materials, reinforcing materials.

The invention discloses a carbon-based composite material and its preparation method and application, which belongs to the technical field of carbon material preparation. The carbon-based composite material comprises the substrate, carbon film and structural carbon which are integrated into one body. The electron, ion and atom transmission and chemical structure characteristics of the carbon-based composite materials are modified by the carbon film and structural carbon containing alkali and/or alkali earth elements resulting in the carbon-based composite materials having excellent physical and chemical properties, which can be used for various applications including battery electrodes, capacitor electrodes, various sensors, solar cell electrodes, electrolytic water hydrogen production electrodes, hydrogen storage materials, catalysts and catalyst carriers, composite materials, reinforcing materials.

A system and process for producing macro length carbon nanotubes is disclosed. A carbonate electrolyte including transition metal powder is provided between a nickel alloy anode and a nickel alloy cathode contained in a cell. The carbonate electrolyte is heated to a molten state. An electrical current is applied to the nickel alloy anode, nickel alloy cathode, and the molten carbonate electrolyte disposed between the anode and cathode. The resulting carbon nanotube growth is collected from the cathode of the cell.

A system and process for producing macro length carbon nanotubes is disclosed. A carbonate electrolyte including transition metal powder is provided between a nickel alloy anode and a nickel alloy cathode contained in a cell. The carbonate electrolyte is heated to a molten state. An electrical current is applied to the nickel alloy anode, nickel alloy cathode, and the molten carbonate electrolyte disposed between the anode and cathode. The resulting carbon nanotube growth is collected from the cathode of the cell.

Filled carbon nanotubes (CNTs) and methods of synthesizing the same are provided. An in situ chemical vapor deposition technique can be used to synthesize CNTs filled with metal sulfide nanowires. The CNTs can be completely and continuously filled with the metal sulfide fillers up to several micrometers in length. The filled CNTs can be easily collected from the substrates used for synthesis using a simple ultrasonication method.

Filled carbon nanotubes (CNTs) and methods of synthesizing the same are provided. An in situ chemical vapor deposition technique can be used to synthesize CNTs filled with metal sulfide nanowires. The CNTs can be completely and continuously filled with the metal sulfide fillers up to several micrometers in length. The filled CNTs can be easily collected from the substrates used for synthesis using a simple ultrasonication method.

Provided is a method for growing carbon nanotubes that enables the growth of high-density carbon nanotubes. A high frequency bias voltage is applied to a loading table on which a wafer W having a catalytic metal layer is mounted to generate a bias potential on the surface of the wafer W, and oxygen plasma is used to micronize the catalytic metal layer to form catalytic metal particles. Thereafter, hydrogen plasma is used to reduce the surface of the catalytic metal particles to form activated catalytic metal particles having an activated surface. By using each activated catalytic metal particles as a nucleus, carbon nanotubes are formed.