Cellulose is formed as a result of biosynthesis from plants, bacteria or animals. While nanocellulose is referred to as cellulosic extract with dimensions at nano-scale. In plants, strength and stiffness are provided due to the presence of densely packed cellulose fibrils which are made up of lignocellulosic biomass that have a crystalline zone. Along with this crystalline zone, there is another amorphous portion that also provides the plants with flexibility. The length of these fibres varies from a few micrometres and diameters of less than 100 nm. Its properties include biodegradability, lightweight, density around 1.6 gm/c, and its equivalency to cast iron. The presence of a reactive hydroxyl group makes it even more beneficial for surface functionalization. Natural cellulose is present in the cell walls. Nanocellulose material can be categorized into three types:  nanofibrillated cellulose (NFC), bacterial nanocellulose (BNC), and cellulose nanocrystals (CNC). 

Three types differ from each other on the nanoscale because of their size, composition, and form. Among these, BNC is extracted from microbial-basedE nanocellulose while other two types CNF and CNC, are obtained from the plants through mechanical chemical, and physical disintegration or sometimes a mix of these processes. BNC is the only type of cellulose that can be altered through biotechnology and can be modified to receive hydrogels with high purity, mechanical strength, and an interconnecting microphone system (Khalid et al., 2021; Abitbol et al., 2016). 

Because of its extensive and distinctive properties, which include increased mechanical strength, tunable surface chemistry, crystallinity, biodegradability, and nontoxicity, and high aspect ratio, nanocellulose is providing a potential renewable substrate for its extensive uses in industrial applications. These applications can include the provision of a renewable substrate for packaging, coatings, and fillers, significantly increasing the commercial market (Sharma et al., 2019). 

When nanocellulose is combined with other materials like steel and Kevlar to form composites, it becomes considerably lighter. It can be used as a replacement material that can partially be used in the place of steel and other metals and fibreglass. Lightweight armour and ballistic glass are already being considered by the US Department of Defense. The construction of small Military robots reinforced with nanocellulose particles is being discussed, and this might include soldiers' helmets. This includes all the things which require the highest strength to weight ratio, especially in the military sector. 

Nanocellulose is further made up of coiled sugar chains, which are expected from wood and other plant cell walls. It is removed by grinding the pulp or breaking it into tiny bits using chemicals. The material is becoming popular because of its strength despite its small size and fewer defects. The addition of 10% nanocellulose to the composite material increases its efficacy by 70%.  In the United States, this material is being utilized in vehicle parts, theatre-based construction materials, and materials related to the protection of military personnel on the battlefield. Recent research has revealed that nanocellulose also plays an important role in improving the impact strength of composite materials. Because of its properties, it can be potentially used to create large and small parts of vehicles, boats, aeroplanes, gun stocks, optics, or any other material, including weapons that require lightweight and durability. A combination of nanocellulose and graphite particles might have the probability of being used in ballistic missiles and for other military uses. Graphene is one of the potential materials to be used with nanocellulose, because of its excellent characteristics, which include the conductivity and increased ability to make composites. It is the main focus of many researchers and industries such as Nanographenex.

According to researchers in Brazil, nanocellulose extracted from bananas gives a 30% lighter and four times stronger material than petroleum-based plastic. Ballistic panels from nanocellulose have the capacity to stand motor pieces, and bullets are being created. A wood core is encased by synthetic resins and fibres in these panels. The panels are then fitted into tent frames because of their capacity of being lightweight that can be easily carried by two people. Without the availability of equipment or experience, four troops can easily install this nanocellulose panel in about half an hour. During experimentation, it was observed that the flexible straps provide flight support in preventing the tent from being damaged during the milliseconds of the explosion. The wood is robust and light, while the synthetic elements around it provide tensile strength. Wood bends and finally ruptures when subjected to a rapid force preventing the splinters from flying around, preventing the damage of hazardous missiles. The composites surpass pure wood in terms of durability, ease of maintenance, and resistance to decay, along with insect attack. The addition of nanocellulose to ballistic panels improves the characteristic by improving the blast resistance. 

Textiles serve a wide range of purposes, therefore, are considered important components of military equipment. This includes parachutes, combat outfits, aeroplane material, shelter armours, fire-resistant fabric, and many other areas where textile is used in the military. Clothing embroidered with nanocellulose can protect military troops against viruses, poisonous gases, and other dangerous chemicals. Furthermore, it may enable continuous monitoring of bodily processes. The use of nanotechnology in the textile sector includes self-cleaning textiles, textile having antimicrobial activity, clothing having the capacity of reducing injuries and accidents. 

Nanocellulose is used in contemporary fabrics to give several benefits. Nanocellulose may be beneficial for applications including thermal insulation because of its superior characteristics as compared to other materials. Military body armour should have specific qualities, which include mechanical strength, lesser weight, hydrophobicity, antimicrobial activity, and anti ballisticity. Nanocellulose has the potential to have all these characteristics, which are necessary for the body armour to be used in the military (Norrrahim et al., 2021). 

Nanocellulose has been the subject of discussion since the early 1980s. But due to some complications, there has been resistance to commercialization. For example, nanocellulose needed 30,000 kWh/ton to delaminate the fibres at the initial step, which requires high capital of energy. By utilizing fibre pretreatment, the claims are being made to have reduced this energy demand by 98%. But the development is still at early stages and needs time before its commercial launch. 

References 

Abitbol, T., Rivkin, A., Cao, Y., Nevo, Y., Abraham, E., Ben-Shalom, T., ... & Shoseyov, O. (2016). Nanocellulose, a tiny fibre with huge applications. Current opinion in biotechnology, 39, 76-88.

Khalid, M. Y., Al Rashid, A., Arif, Z. U., Ahmed, W., & Arshad, H. (2021). Recent advances in nanocellulose-based different biomaterials: types, properties, and emerging applications. Journal of Materials Research and Technology.

Norrrahim, M. N. F., Kasim, N. A. M., Knight, V. F., Ujang, F. A., Janudin, N., Razak, M. A. I. A., ... & Yunus, W. M. Z. W. (2021). Nanocellulose: the next super versatile material for the military. Materials Advances.

Sharma, A., Thakur, M., Bhattacharya, M., Mandal, T., & Goswami, S. (2019). Commercial application of cellulose nano-composites–A review. Biotechnology Reports, 21, e00316.