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Since the occurrence of fires has yet to experience a significant decline in many countries around the world, there is an increasing need for researchers to investigate and develop improved ways to tackle this global issue.
The Need to Improve Fire-Retardant Materials
In 2018, fire departments within the United States of America responded to more than 1.3 million fires, resulting in 3,655 fatalities, 15,200 injuries and a cumulative property loss of around USD 25.6 billion.
That same year, the United States experienced a total of 50,083 wildfires, more than 8,500 of which occurred in the state of California alone. As the US is an industrialized nation that claims a high level of interest in the safety of their citizens, these numbers are astonishing.
Exploring the Promise of Nanotechnology
While the exact number of fires and related civilian injuries and fatalities in the US has appeared to decrease slightly over the past several years, these numbers are still considered to be very high and unacceptable.
To resolve these concerns, several researchers have used nanotechnology to create innovative fire protection solutions.
Nanotextiles as flame-retardant materials
Since textiles are one of the most common ignition sources in fire accidents, many flame-retardant textiles have been incorporated into protective clothing, carpets, furniture, curtains, flooring, sleepwear, mattresses and other industrial textile materials.
As the most widely used polymer nanocomposite, montomorillonite (MMT) nanoclays exhibit unique mechanical, thermal, and flammability barrier properties that have led to their incorporation into flame-retardant textiles.
Carbon nanotubes (CNT), which are formed from a hexagonal network for bonded carbon atoms, have also demonstrated flame-retardant capabilities. More specifically, the char layers within polymer/CNT systems act as a heat barrier and thermal insulator, reducing the flammability of their substrates.
Nanocyl, which is a Belgium-based company focused on the production of industrial multiwall carbon nanotubes (MWCNTs), was one of the earliest producers of commercially available MWCNT flame-retardant textile coatings. The company’s product, otherwise referred to as THERMOCYLTM, provides exceptional flame barrier properties for a wide range of materials beyond textiles, some of which include glass, metals, thermoplastics and wood.
Video Credit: Company Nanocyl/YouTube.com
Fire suppression systems
By incorporating nanotechnology into fire suppression systems such as fire extinguishers and close-loop suppression systems, fires could be extinguished much more effectively.
One way in which this type of system has been studied is through the development of different chemical mixtures and combinations that could allow burning materials to break down into nanoparticle size. The quality of the fire suppression mixture would then rise, enhancing their effectiveness and strength in fighting fires.
Xi’an WestPeace Fire Technology Co., Ltd is a China-based company that has developed several portable and nanotechnology-driven fire extinguishers. The basic working principle behind their nanoparticle fire extinguishing technology is to reduce the size of dry chemical extinguishing particles to approximately 0.1 micrometers (µm). This then helps to generate an impressive momentum that forces the particles directly into the fire, reducing the amount of residue that remains after the fire has been eliminated.
In addition to being the smallest portable fire extinguisher currently available on the market, Westpeace states that its line of nanoparticle firefighting products is environmentally friendly and non-toxic.
Click here for more information on nanotechnology equipment.
With the global population on the rise, manufacturers have met the increasing demand for building materials by developing lighter, stronger and more durable materials that can be produced at a faster rate.
Unfortunately, not all manufacturers have considered the flammability of their materials. In an effort to address these fire safety concerns without compromising on the ability to meet production demands, several different nanotechnologies have been integrated into novel building materials.
Whereas traditional coatings on wood structures have included ammonium phosphates or sulfates, chlorides, oxides, borates or other metal salts, many of these chemicals and their combustion products are highly toxic.
Several efforts have been made to investigate how the replacement of these harsh chemicals with nanocoatings could provide enhanced fire protection, reduced toxicity to construction workers and improved resistance to biolesions.
Some nanocoatings that have shown promising results for the fire protection of wood include layered silicate nanoclays such as MMT, nanoparticles of inorganic flame retardants, silica nanoparticles, and MWCNTs.
Potential Limitations of Nanotechnology in Fire Safety Applications
Aside from nanotextiles and novel fire suppression systems, the application of nanotechnology in fire safety systems can also be found in polymeric coatings used in the automotive industry, nanofiber mats and hydrogels.
Despite its potential, concerns surrounding the potential nanotoxicity of these materials has limited their integration into more commercial products and the increased use of nanoparticles has revealed their ability to alter natural immune function, leading to inflammation in various organs such as the liver, kidney and lungs.
Fortunately, many of the toxicity studies that have provided this information have allowed researchers to determine safer concentrations, sizes and surface patterns of NPs for their given applications.
References and Further Reading
- “Facts + Statistics: Wildfires” – Insurance Information Institute
- “Fire Loss in the United States During 2018” – The National Fire Protection Association
- Olawoyin, R. (2018). Nanotechnology: The future of fire safety. Safety Science 110(Part A); 214-221. doi:10.1016/j.ssci.2018.08.016.
- Norouzi, M., Zare, Y., & Kiany, P. (2014). Nanoparticles as Effective Flame Retardants for Natural and Synthetic Textile Polymers: Application, Mechanism and Optimization. Polymer Reviews 55(3); 531-560. doi:10.1080/15583724.2014.980427.
- “Company” – Nanocyl
- “Nano Particles Portable Fire Extinguisher” – Xi’an Westpeace Fire Technology
- Vakhitova, L. N. (2019). Chapter 16 Fire retardant nanocoating for wood protection. In: Nanotechnology in Eco-efficient Construction. 2nd ed; 361-391. doi:10.1016/B978-0-08-102641-0.00016-5.
- Park, H. J., Sohn, J., Kim, Y., Park, Y. H., Han, H., Park, K. H., et al. (2015). Acute exposure to silica nanoparticles aggravate airway inflammation: different effects according to surface characteristics. Environmental & Molecular Medicine 47. doi:10.1038/emm.2015.50.