Warren has discussed the use of carbon fiber in future vehicles and Schmidt et al have outlined the unique applications of carbon-carbon composite materials.
In space, solar sails attached to a spacecraft reflect photons of sunlight and harness their momentum; the sail must however be super-lightweight to benefit from the massless particles bouncing off the sail and must be extremely reflective to maximize the propulsive force. More energy is delivered when closer to the sun. The force on the sail will constantly accelerate the spacecraft over time and will eventually exceed the velocity of a rocket. Energy Science Laboratories has recently developed a carbon fiber web with an areal weight of 5 gm-2. The mesh is a network of criss-crossed carbon fiber nanotubes, which will not require a cumbersome deployment structure, since it can be folded and packed, but will jump out into position when released. Additionally, the sail can be propelled by lasers heating the sail, making it glow orange/white, while the web still maintains its integrity.
Nanoporous carbon fibers and carbon nanotubes exhibit a high H2 storage capacity. Carbon nanotubes have also been demonstrated to store Li efficiently. The textile industry is likely to be hugely impacted by nanotechnology.
Carbon nanotubes can be either semiconducting or conducting, depending on the chirality and diameter of the nanotube. These nanotubes can conduct heat as efficiently as diamond and electricity as efficiently as copper.
To improve the mechanical properties of activated carbon fiber, a dual viscose and PAN based carbon filament has been developed, with the core made of PAN based fiber and an external layer of viscose based fiber, which can readily be activated with CO2. The central core comprises of about 50 discontinuous PAN filaments held together by a continuous filament of PVOH and concentrically wrapped by discontinuous viscose filaments using a friction spinning process. The dual filament is carbonized in a inert atmosphere at 900C and activated by CO2 at 900C. Another way of achieving a coating of cellulose would be to apply a solution of cellulose in a mix of water and 4-methylmorpholine-/V-oxide.
The cost of carbon fiber will always be an important factor and has been an issue that has been continually championed by Zoltek.
There is big consumption of carbon fibers and carbon-carbon composite products, thus this would require substantial additional investment in manufacturing capacity to enable production to keep pace with such a level of demand.