NANO TECHNOLOGIES

Nanotechnology In Space And Defense

Nanoparticles have been proven to be very beneficial in the field of defense. Nanoparticles have the ability to make properties of certain materials stronger, lighter, and more efficient. Nanotechnology has the potential to improve our department of defense by making numerous applications stronger, safer, and more efficient.

The use of high-strength, lightweight materials have the ability to reduce of spacecraft by 30 percent. An example of this are composites of nanoparticles and polymers that allows for high-strength, lightweight materials. Certain nanoparticles such as carbon nanotubes can be functionalized, meaning they can be customized to perform a specific function through bonding oxygen atoms to their surface. These oxygen atoms assist polymer matrix coincide with the carbon nanotubes to provide greater strength.

Silica aerogels are also a very efficient nanoparticle with many great uses. An aerogel is where the liquid is replaced by gas. The silica aerogels consist of silica nanoparticles intertwined with nanopores filled with air. The air allows the nano aerogel to be one of the best thermal insulators know to man.

A proposed application of the carbon nanotubes is a space elevator. Just like an elevator in a hotel, the space elevator would be able to transport people and materials from earth to space. One end of the 90,000 kilometer cable would be attached to a top of an asteroid and the other end would be floating in the ocean.

On top of making materials stronger and lighter through nanomaterials, shapes of the material can also be altered as well! Nanotechnology has the ability to make bulky military field radios shrink to a size of a button that can be worn on a collar! An equipments shape can be morphed to improve performance and efficiency. A example of this is instead of using heavy hinges to extend and retract the wings of an aircraft, the wings shape can be altered by using a carbon nanotube polymer composite that bends when a voltage is applied. A huge limitation of military aircraft today is that one plane is designed to do one job. For instance, one is made to do bombing missions while another is designed to do reconnaissance. Having specific proprietary planes limit these planes to certain airfields or ships for takeoff and landing. If an aircraft is able to morph its shape through the use of nanoparticles, one aircraft would be able to be used universally for all roles in order to hugely cut down cost and improve efficiency.

Safety is often a main concern in the field of defense. Nanoparticles can be used to assist in keeping humans and equipment safe. In a hazard mitigation system, there is a sensor that detects an agent and responds to isolate or detoxify the agent. Nanoscale materials are used in decontaminating portion of the system at the molecular level. Researchers are also creating nanofiber mats that filter hazardous material. The toxic molecules become attached to the nanofibers while air is able to pass through the nanofiber mat. Liquid armor is a type of fabric in kevlar vest that is soaked in STF. STF is a suspension of hard nanoparticles in polyethylene glycol. In normal circumstances, the fabric is deformable and flows like a liquid. When struck by a bullet the material transforms to a rigid material and blocks the projectile from striking the soldier's body. This example highlights how nanomaterials are able to modify a material's shape and composition in order to fill a specific role.

Propeller shafts on ships are subjected to damaging galvanic corrosion from being in a saltwater environment. This electrochemical process corrodes metal resulting in a life expectancy of only one year. Four Navy ships are currently testing a new ceramic nanocomposite coating material that can withstand the corrosion. This coating consists of alumina titania, this coating has been able to keep the propeller shaft damage free after five years of testing compared to a life expectancy of one year without the coating!

A material's energy can be altered through changing the size of the nanoparticles. Nanoparticles have more surface area in contact between the particles different chemicals that make up an explosive. Due to its greater surface area it allows for faster reaction rates that that result in a more powerful explosion. In weapon systems, this is very beneficial allowing them to utilize reate amounts of energy resulting in more lethal results. Currently the U.S. Army is developing batteries that utilize nanomaterial electrodes to increase the energy density (the amount of energy stored) in batteries by altering the chemical composition.

Three roll milling is a dispersion technique that employs both shear flow and extensional flow created by rotating rolls of different speed to mix and disperse CNT, CNF, Graphene, or other nanoscale particles into polymers or other viscous matrixes. It is a very appealing process that benefits the environment by eliminating the solvent. Three roll mill is an extremely effective dispersion tool for nanocomposites containing fiber-like filler such as carbon fiber, glass fiber, carbon nanotube etc. Because of the powerful shear force, the mixer can reach a higher degree of intercalation/exfoliation within a short period of time.