We plan to produce in continuous process large volumes of high quality single-walled carbon nanotubes at a reasonable price to facilitate the full integration into commercial products. We define nanoparticles as free particles having an average diameter well below 100 nm and typically in the 1 â€“ 30 nm range with narrow particle size distribution. We know that carbon nanotubes (CNTs) have been studied for many different applications because of their exceptional electrical and mechanical properties. Carbon nanotubes have already been shown to be useful for a variety of applications like field mission devices, nano-scale electromechanical actuators, field-effect transistors (FETs), CNT based random access memory (RAM), and atomic force microscope (AFM) probes. We use a method called Chemical Vapor Deposition (CVD). This method is low cost and allows for us to create high purity products (90%-98%). With CVD, we can also control the diameter and length of the nano-tubes produced. We plan to offers single wall carbon nanotubes, produced by arc discharge and double wall nanotubes, produced by CVD. Nanotubes are commonly produced through methods such as arc discharge, laser ablation, or chemical vapor deposition, nanotubes can also be produced by ball milling, hydrothermal pressure, decomposition of buckyballs, and annealing of soot. However, obtaining large enough quantities of the material continues to be one of the biggest challenges facing nanotechnology researchers. We have developed a novel system based on CVD growth, as it enabled the production of both single and multi-wall nanotubes of reasonably high quality and consistency while offering the greatest potential for scale up. At the same time we also work on producing high quality single-walled carbon nanotubes by using a unique innovative, plasma-based process. As compared to the other techniques for commercially producing single-walled carbon nanotubes (CVD, Gas Phase CVD, Arc, Laser Ablation) this method is more viable but it is still to be worked out completely so that it can be used commercially.
Some of the methods of Characterizing SWNT are:-
1. Transmission electron microscopy (TEM) allowing for the assessment of detailed structures and Scanning electron microscopy (SEM) providing overviews of sample structures while less sensitive to sample preparation and homogeneity than TEM.
2. We plan to start our first high-capacity plant for up to 0.35 tons/yr in early 2008 producing SWCNTs at 1 kg per day (Calculated approximations done by advanced techniques). We have worked upon and selected to start our work in Hyderabad.
3. The only manufacturing unit for CNT is DMSRDE Defense Materials and Stores Research and Development Establishment (DMSRDE) and we have been working closely to analyze and work out India specific innovative ideas so that we can work with close co-operations with other agencies that are in Nanomanufacturing.
Nano tubes have important applications in the following:-
1. CNT based solar cells
2. Nano tube filter - water purification
3. Nanotube sensors
4. Nano Fab
5. MEMS devices
Single-walled carbon nanotubes will see a great deal of applications in the following areas:-
* Aerospace : Electrically active, thermally conductive polymers, nanotube structural enhanced composites; etc.
* Defense : Enhanced lightweight ballistic protection, field sensors; etc.
* Energy : Hydrogen storage for fuel cells, battery electrodes, etc.
* Electronics/IT : Heat sinks; nanochips, hard drive heads, etc.
* Medical : New drug delivery medications, devices, etc.
* Sports : Enhanced golf, tennis, baseball, cycling equipment, etc.
* Telecom : Antennas, microwave amplifier devices, etc.
* Automotive : Fuel cells, structural components, electronics; etc.
* Consumer : Flat panel displays, textiles, paint, efficient lighting, water filtration, etc.
CVD Plant Information â€“ (Nano manufacturing)
Chemical vapour deposition or CVD is a generic name for a group of processes that involve depositing a solid material from a gaseous phase and is similar in some respects to physical vapour deposition (PVD). PVD differs in that the precursors are solid, with the material to be deposited being vaporized from a solid target and deposited onto the substrate.
A CVD apparatus will consist of several basic components:
Â· Gas delivery system â€“ For the supply of precursors to the reactor chamber
Â· Reactor chamber â€“ Chamber within which deposition takes place
Â· Substrate loading mechanism â€“ A system for introducing and removing substrates, mandrels etc
Â· Energy source â€“ Provide the energy/heat that is required to get the precursors to react/decompose.
Â· Vacuum system â€“ A system for removal of all other gaseous species other than those required for the reaction/deposition.
Â· Exhaust system â€“ System for removal of volatile by-products from the reaction chamber.
Â· Exhaust treatment systems â€“ In some instances, exhaust gases may not be suitable for release into the atmosphere and may require treatment or conversion to safe/harmless compounds.
Â· Process control equipment â€“ Gauges, controls etc to monitor process parameters such as pressure, temperature and time. Alarms and safety devices would also be included in this category.
We are working to get alternatives of many part of a CVD unit build indigenously. Cost of setting up a CVD plant can vary from 25 lacks to a few crores .