UltraPure Steam in Nanotechnology
Improving the growth rate and uniformity of carbon nanotubes is a major hurdle to transfer of this technology from research to production. For repeatable and reliable CNT fabrication, tools are needed to control whether CNT are single- or multi-wall, straight or bent, long or short, and clean or dirty. Water vapor addition to the process is turning out to be the main control knob for all of these processes. Precise delivery of water vapor will determine what the CNT looks like, what its yield is, and how contamination free the structure is. Water vapor is both the gas pedal and the steering wheel for CNT fabrication.
The process of growing CNT on catalysts leads to self-poisoning of the catalyst and cessation of the process. Through the addition of small amounts of water vapor, the catalyst can be kept free of molecular contamination. This enables longer carbon fibers to be grown under the same general process conditions. Adding more water first leads to breaks in the CNT, which enable more tube opens. Further addition ceases the process. Metallic species are the sites for bends and branches of CNT. Addition of water vapor can react with metallic species to volatize and remove them, which stops branching and bending. Water vapor changes the CNT from multi-walled to single wall and ensures the single wall tube are clean and free of amorphous carbon debris.
RASIRC technology is the first and only system to generate ultra pure water vapor that can deliver precise amounts of water vapor that is purified for both ionic contaminants and dissolved gases. Needing only house de-ionized (DI) water and power, the RainMaker Humidification System (RHS) adds controlled amounts of water vapor to any carrier gas. It can humidify inert gases, as well as oxygen, hydrogen, or corrosive gases. The system is capable of delivering into both atmosphere as well as vacuum process pressures.
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