Microwave plasma in hydrocarbon liquids

Abstract

The generation of microwave plasma in liquid with vapor bubbles has been achieved and will soon be applied to high-speed chemical vapor deposition. Vapor bubbles are induced from an electrode by heating. The deposition rate of diamondlike carbon films depends on the pressure and the power of the microwave supply. Polycrystalline silicon carbide is synthesized on a silicon substrate in a mixture of n-dodecane and silicone oil. The dispersion of water droplets in liquid creates many pores on the silicon carbide films. The synthesis of carbon nanotubes can be achieved in liquid benzene.

Optimization and analysis of shape of coaxial electrode for microwave plasma in water

“…[37][38][39] The temperature of the inner electrode at plasma ignition was measured by inserting a thermocouple into the inner electrode and it was concluded that the plasma is generated when the temperature of the electrode reaches the saturation temperature of the liquid. 12 This result indicates that there is a relationship between the ignition temperature and the saturated temperature.…”

“…It has been reported from experiments on amorphous-carbon deposition in a hydrocarbon liquid, that the deposition rate is found to be approximately 9000 times faster than that for typical chemical vapor deposition in gases. 12 The MW plasma generated in an organic liquid has been researched in our previous studies. [12][13][14][15] Plasma is generated by supplying MW radiation of 200 to 400 W at the tip of a submerged electrode similar to a monopole antenna widely used for conventional gaseous plasma.…”

“…12 The MW plasma generated in an organic liquid has been researched in our previous studies. [12][13][14][15] Plasma is generated by supplying MW radiation of 200 to 400 W at the tip of a submerged electrode similar to a monopole antenna widely used for conventional gaseous plasma. Mukasa et al 15 observed the MW plasma generated in n-dodecane using a high-speed camera, and reported that bubble containing plasma was generated at the tip of the electrode.…”

“…Utilizing the plasma within a liquid is expected to be effective in the decomposition of environmentally harmful dissolved substances [4][5][6][7][8] or for medical purposes such as sterilization or even a surgical plasma scalpel. 9 New plasma chemistry using liquids as a raw material enables the synthesis of some nanomaterials [10][11][12] and the production of fuel gas. 13 Another example of the utility of this chemistry is the deposition of diamond, 14 diamondlike-carbon, 12 and silicon carbide 12 to a substrate by irradiating microwave ͑MW͒ or radio-frequency waves ͑RF͒ in liquid.…”

“…9 New plasma chemistry using liquids as a raw material enables the synthesis of some nanomaterials [10][11][12] and the production of fuel gas. 13 Another example of the utility of this chemistry is the deposition of diamond, 14 diamondlike-carbon, 12 and silicon carbide 12 to a substrate by irradiating microwave ͑MW͒ or radio-frequency waves ͑RF͒ in liquid. It has been reported from experiments on amorphous-carbon deposition in a hydrocarbon liquid, that the deposition rate is found to be approximately 9000 times faster than that for typical chemical vapor deposition in gases.…”