In the crust of the earth, aluminum is the third most abundant and plentiful element. Aluminum is well known for its everyday use in various things, including cans and other objects that are regularly used by us. Its characteristics and properties increase its use in the industry, especially in automotive and aerospace industries where it is employed in the alloys making an ideal element. Aluminum is a lightweight metal and is naturally protected from corrosion by an oxide coating. This property makes it an ideal element and metal to be used in the aerospace industry. Other properties include its ability as a conductor of heat and electricity. The thermal conductivity of aluminum is employed in a variety of heat dissipation applications. Following are the major uses of aluminum nanoparticles:

Aluminum nanoparticles and military devices

The use of nanosized particles for fuels and propellants has increased the interest of researchers because of increased benefits over micron size counterparts. There are various advantages of nanoparticles which include shortened delay time of ignition and a substantially shorter burning time. In small scale propulsion systems, shortened burn time allows for more thorough combustion. Nanoparticles having the highest specific surface area increase the transfer rates of heat. From the standpoint of synthesis, these nanoparticles can provide favorable features for new energetic propellants. 

Aluminum powder is a regularly utilized component in various energetic materials. In rocket propellants, it increases the quantity of energy and the temperature of the flame. Aluminum nanoparticles have lately become accessible for use in various energetic materials because of their significant use in increasing the burning rates and lowering the ignition time and temperature. Because of these features, ultrafine aluminum particles are preferably used in propellants. Aluminum is active burning fuel, especially when it is measured in volumes. Because of these characteristics, it becomes an ideal element to be used in propellants, explosives, and pyrotechnics as it has a high combustion temperature and energy density. Aluminum is most commonly available and inexpensive. For a long time, i.e., over a century, aluminum has been used as an addition in energetic compositions, which include thermite, explosives, and pyrotechnics. Aluminum is now being used in rocket propellants (Sadeghipour, Ghaderian & Wahid, 2012). 

Reduced sensitivity

The use of aluminum nanoparticles increases the friction sensitivity of the propellants. It has been observed that propellants coated with micrometric aluminum nanoparticles have increased ballistic performance when more metal is added to the mixture because of its high content of aluminum. The mixture of nano aluminum and metal has resulted in higher efficiency as compared to those propellants, which only contain aluminum nanoparticles. The propellant can reach its higher strength if the surface of the powder is increased.

Medical uses

The use of aluminum nanoparticles for the encapsulation of nonionic insoluble drugs can act as site specific Drug Delivery System. Aluminum oxide nanoparticles having high dielectric and abrasive qualities having the potential to be used as Orthopaedic implant. It can be considered more optimum as it has left side effects on the structure of bone compared to other traditional method materials and methods of larger size that had previously been used ((Monteiro‐Riviere, Oldenburg & Inman, 2010). 

Medication delivery: aluminum nanoparticles in the form of ordered mesoporous aluminum oxide have been used to enhance the oral administration of anti-blood pressure drug telmisartan, which is a poorly soluble molecule in water. Nano aluminum oxide particles are also considered to have anticancer capabilities that can be useful in the treatment of cancer. 

Antimicrobial properties: aluminum nanoparticles have a huge surface area, therefore, can exhibit excellent antimicrobial properties.

Biosensing: Aluminum nanoparticles are considered to be providing a promising platform for the detection of various compounds. Bovine serum albumin can be detected by using aluminum oxide as nanoparticles. The surface of a localised surface plasmon resonance sensor was changed using self-assembled anodic aluminum oxide, which results in an ordered Aluminum oxide nanostructure on an LSPR chip for the conduction of biosensing. The findings reveal that the Nano hole with 75 nm diameter and 0.5 μm deep can serve as the most sensitive sensing layer (Hassanpour et al., 2018). 

Nanophotonics

Aluminum nanoparticles have UV optical capabilities in opposition to gold and silver nanoparticles which make them novel plasmonic materials. Aluminum nanoparticles exhibit plasmonic properties in the near-infrared and visible range. The ability to manipulate the form and crystal structure allows for basic research in UV plasmonics and nanophotonics. Aluminum nanoparticles create a strong localised field which helps in sensing and photocatalysis. When the shape of aluminum nanoparticles is directed towards cube and concave cube morphologies, it enables the light energy to concentrate on the sharp corners and tips of the particles, which allows them to sense and do photocatalysis. The surface oxide is a built-in dielectric spacer for researching and harnessing plasma-enhanced phenomena and provides unique functionality in sensing applications.

Photocatalysis

Aluminum is a plasmonic material with a response that extends into the UV range. Promising features of aluminum include its potential in UV plasmonics application, for example, surface-enhanced fluorescence, which is due to its prolonged response, low cost, and ease of manufacture. Other examples of such technologies include surface-enhanced Raman scattering and photovoltaics (Hao et al., 2015).

To generate an antenna reactor, the bimetallic nanoparticles photocatalysis aluminum nanoparticles surface is covered with tiny transition metal nanoparticle islands. The plasmonic aluminum core drives plasmonic citation in the transition-metal Islands upon illumination, which helps in improving the potential to capture light for the conduction of chemical processes. The logical manufacture of nanoparticle photocatalysis and its appropriateness to industrial chemical processes is enhanced by the modular synthesis of a transition metal that is covered by aluminum nanoparticles. Photocatalysis is effective in environmental cleaning. The combination of aluminum mixed with catalyst is an efficient technique to tune the light absorption range during the process of removal of organic pollutants. It also leads to a large increase in photocatalytic activity under UV light irradiation. 

Aluminum is found everywhere because of its increased utilisation. They may be found in a variety of daily items, including vehicles, aerospace manufacturing, furniture, and light fixtures. Aluminum is preferred for construction because of its properties, including its malleability, durability, and lightweight. Scratch and abrasion resistant coatings on sunglasses are also included as one of the commercial applications of aluminum and Aluminum oxide nanoparticles (Monteiro‐Riviere, Oldenburg & Inman, 2010).  

 

 

References

Hao, Q., Wang, C., Huang, H., Li, W., Du, D., Han, D., ... & Chu, P. K. (2015). Aluminum plasmonic photocatalysis. Scientific reports, 5(1), 1-7.

Hassanpour, P., Panahi, Y., Ebrahimi-Kalan, A., Akbarzadeh, A., Davaran, S., Nasibova, A. N., ... & Kavetskyy, T. (2018). Biomedical applications of aluminium oxide nanoparticles. Micro & Nano Letters, 13(9), 1227-1231.

Monteiro‐Riviere, N. A., Oldenburg, S. J., & Inman, A. O. (2010). Interactions of aluminum nanoparticles with human epidermal keratinocytes. Journal of Applied Toxicology: An International Journal, 30(3), 276-285.

Sadeghipour, S., Ghaderian, J., & Wahid, M. A. (2012, June). Advances in aluminum powder usage as an energetic material and applications for rocket propellant. In AIP Conference Proceedings (Vol. 1440, No. 1, pp. 100-108). American Institute of Physics.