Patent KR-100841293-B1 (KR)
Title: Method and apparatus of synthesizing carbon nanotubes with ultra sonic evaporator
Inventor: JEONG NAM JO
IPC: B82B3/00
Filed: 2007-02-09
Granted: 2008-06-25
Abstract: A successive preparation method of carbon nanotube and a device for the preparation are provided to mass-produce carbon nanotube of uniform size under quantative control, to control the shape of the carbon nanotube easily, and to reduce manufacturing cost by employing ultrasonic oscillation gasification for pulverizing metal catalyst liquid mixture comprising metal catalyst particle and liquid carbon source. A device for successive preparation of carbon nanotube has: a raw material supply device part(1); a gasifying device part(2); a transportation gas supply device part(3); a reaction device part(4); a successive collector part(7); and a vacuum device part(6) which has a sample bottle(78) connected to the successive collector part and a vacuum pump(61) for removal of inner pressure of the reaction device and remained oxygen. The raw material supply device part(1) has a syringe pump(11) for quantative supply of the metal catalyst liquid mixture(12). The drops of the supplied mixture from the syringe pump fall down onto an ultrasonic oscillation plate(21) concurrently with being pulverized to very small particle. The ultrasonic oscillation plate is controlled by separate an ultrasonic oscillation controller(22) that controls the operation time of on/off timer depending on the supplied amount in the supply device. The pulverized precursor is transported to the reaction device part of a high temperature of 600 to 900deg.C by means of a transportation gas(31) which is supplied from the outside. The transportation gas is controlled by a flux controller(32), mixed homogeneously in a mixer(33), and transported to the gasifying device part. The reaction device part has a perpendicular tube(44), a heater(42) surrounding the tube, and a reactor temperature controller(43) for the heater. The reaction device part is equipped with: the successive collector part(7) for successive collecting of the remained particles in the reaction device part and of carbon nanotube which is mainly produced in gas state; and vacuum device part which is combined with the successive collector in order to remove inner pressure of the reaction device and remained oxygen, in perpendicular direction. The successive collector has a screw(75) inside, and the screw is driven by a motor(76) of which velocity depends on the amount of the produced carbon nanotube by means of a motor control device(77). The produced carbon nanotube from the screw is collected in the sample bottle. A preparation method of carbon nanotube comprises steps of: supplying a metal catalyst liquid mixture comprising liquid carbon source and metal catalyst particles after completing the device for successive preparation of carbon nanotube which employs ultrasonic oscillation of automatic control for operation time and operation degree; producing precursor of uniform nano-size having metal catalyst particles, carbon and hydrogen by gasifying for pulverization of the metal catalyst liquid mixture in the ultrasonic oscillation system for automatic control of the operation time and operation degree; and transporting the pulverized nano-size precursor by transportation gas, separating the precursor into carbon, hydrogen and metal catalyst particles, respectively by thermal decomposition, absorbing only the separated carbon particles on the metal catalyst particles, and forming the shape and structure of carbon nanotube by diffusion, and the obtained highly pure carbon nanotube is collected successively in a perpendicular state for successive preparation.