This article was updated July 2023.
Nanocellulose is a light solid substance obtained from plant matter which comprises nanosized cellulose fibrils.
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A Brief History of Nanocellulose
Nanocellulose is a modern form of the natural plant-based polymer, cellulose. Plants rely on cellulose to maintain the strength and structure of cell walls. For hundreds of years, the properties of cellulose have been leveraged to produce various essential materials, from paper and textiles to plastics and photographic film.
Scientists have been aware of the tiny microfibers that make up cellulose for centuries. These tiny microfibers bestow cellulose its strength and performance properties. With the help of technological advances, nanocellulose was discovered in the early 1980s. Now, scientists are able to exploit the microfibrils that make up these microfibrils, known as nanocellulose, which forms the basic building blocks of cellulose.
Due to the increased surface area to volume ratio of nanocellulose, it has unique properties compared to cellulose and its microfibers. Scientists are interested in leveraging these into various applications, as discussed below.
Properties of Nanocellulose
Nanocellulose is a pseudo-plastic and possesses the property of specific kinds of fluids or gels that are generally thick in normal conditions. The lateral dimensions of nanocellulose range from 5 to 20 nm, and the longitudinal dimension ranges from a few 10's of nanometers to several microns.
The key properties of nanocellulose are listed below:
• Lightweight.
• Stiffer than Kevlar®.
• Electrically conductive.
• Non-toxic.
• Low-density.
• The crystalline form is transparent, and gas impermeable.
• It can be produced in large quantities in a cost-effective manner.
• It has a very high tensile strength - 8 times that of steel.
• It is highly absorbent when used as a basis for aerogels or foams.
• The raw material - cellulose - is the most abundant polymer on earth.
• Nanocellulose is biocompatible, meaning that it is not toxic to living tissue and can, therefore, be used in biomedical applications.
• Due to its plant-based origin, nanocellulose is also biodegradable.
How is Nanocellulose Produced?
Nanocellulose is generally produced from wood pulp though it can also be prepared from any cellulosic source material. Nanocellulose is produced using the following steps:
- Remove non-cellulose impurities from the wood pulp using a homogenizer. The high-pressure homogenizers used in the production process help delaminate the cell walls of the fibers and separate the nanosized fibrils.
- Separate the cellulose fibers by beating the mixture gently.
- Allow the fibers to form a thick paste of needle-like crystals or a spaghetti-like structure of cellulose fibrils.
- The thick paste that is obtained can be shaped and readily used to laminate surfaces.
Once it is completely separated from the wood pulp, nanocellulose is in a water suspension. At this stage, care should be taken to prevent the formation of rough clumps in cases when the cellulose fibers stick together as the material dries.
Researchers have thus developed a process that allows nanocellulose to dry without the formation of rough clumps. This process thus prevents the cellulose fibrils in nanocellulose from sticking together and enables the cellulose fibers to retain their mechanical properties.
Nanocellulose: It's a Wrap! | Vegar Ottesen | TEDxTrondheim
Video Credit: TEDx Talks/Youtube.com
Applications of Nanocellulose
Nanocellulose has a wide range of applications, from cleaning oil spills to usage in children’s toys. Nanocellulose can be used in the pharmaceutical, food and medical industries. This new material can also replace some petrochemical-based products and is very likely to be cheaper than most other kinds of high-performance nanoscale materials. Some highlight applications of nanocellulose are discussed below.
The Food and Beverage Industry
Nanocellulose can be used as a food packaging material that prevents spoiling food contents and entry of oxygen into the food contents. This new material thus replaces the use of polystyrene-based foams.
In food products, nanocellulose can also be used as flavor carriers and suspension stabilizers, and is safe to use as a food thickener.
Paper Products
When used in paper products, nanocellulose helps to improve the fiber-to-fiber bond strength and acts as a barrier in grease-proof type papers.
It can also be used as wet-end additive to enhance retention, dry and wet strength in commodity type of board and paper products.
Electronics and Material Production
Nanocellulose sheets can be used for electronic displays and windows. Nanocellulose-based sensors have shown use in the monitoring of structures like bridges to detect stress levels.
Nanocelluose can be used to improve the mechanical properties of rubber latex, thermosetting resins, soy protein and starch-based matrixes.
It has also been applied as a fracturing fluid in oil recovery applications.
Medical and Pharmaceutical Applications
In the medical field, nanocellulose can be used for antimicrobial films and water absorbent pads. Nanocellulose can also be used in non-woven products or tissues.
Some intestinal disorders can be treated by tablets comprising dry solid nanocellulose.
In the formulation of pharmaceutical products, nanocellulose has been used as an excipient.
Due to its biocompatibility, nanocellulose is an emerging material in the field of medical impacts, tissue engineering, wound healing, and drug delivery.
Nanocellulose: The Future
The application of green, renewable materials has become increasingly vital across all industries in recent years due to pressure to implement sustainable practices to protect the planet's future. This has led to a great deal of research in the field of nanocellulose, as this material presents a green alternative to synthetic polymers.
Nanocellulose, with its lightweight, high strength and transparent properties, is of great interest for many applications in a wide variety of areas. The material is of immense significance in the ongoing commercialization of nanotechnologies, and researchers and industrialists are analyzing and exploring new manufacturing processes and applications for nanocellulose.
Nanocellulose has been considered a less expensive alternative to carbon fiber and glass fiber for some applications, and is also considered a useful material by the paper and pulp industries that use nanocellulose as an efficient means to increase absorbency in several products such as napkins, ketches towels, and more.
In the coming years, nanocellulose may play a vital role in improving the environmental footprint of many key industries by replacing synthetic or petrochemical-based materials. We can expect further applications of the materials as technology advances.
References and Further Reading
Gumrah Dumanli, A. (2017) ‘Nanocellulose and its composites for biomedical applications’, Current Medicinal Chemistry, 24(5), pp. 512–528. doi:10.2174/0929867323666161014124008.
Trache, D. et al. (2020) ‘Nanocellulose: From Fundamentals to Advanced Applications’, Frontiers in Chemistry, 8. doi:10.3389/fchem.2020.00392.
Nanocellulose: A cheap, conductive, stronger-than-Kevlar wonder material made from wood pulp - Extreme Tech [online]. Extreme Tech. Available at: www.extremetech.com/extreme/134910-nanocellulose-a-cheap-conductive-stronger-than-kevlar-wonder-material-made-from-wood-pulp
Using nanocellulose to create novel composite materials [online]. EMPA Research Institute. Available at: www.empa.ch/plugin/template/empa/3/113491/---/l=2
Materials inspired by Mother Nature: A 1-pound boat that could float 1,000 pounds [online].ACS. Available at: portal.acs.org/portal/PublicWebSite/pressroom/newsreleases/CNBP_029636
“Green” cars could be made from pineapples and bananas [online]. ACS. Available at: portal.acs.org/portal/PublicWebSite/pressroom/newsreleases/CNBP_026933