This article is one of two articles that will cover the potential applications of nanocellulose across industries. The next article will focus on the applications of nanocellulose in the packaging industry.
What is nanocellulose?
Nanocellulose (NC) is the novel form of the most ancient and natural plant-based polymer on earth, cellulose. Discovered in the early 1980s, nanocellulose lost its commercialization purpose because of the high amount of energy (≅ 30,000 kWh/tonne) that was needed to delaminate fibers for its production. Recently, interest in NC has been growing in the light of successful developments by Innventia to lower this high-energy need, leading to the development of energy-saving, pre-treatment methods of cellulose fibers. This has successfully resulted in an energy reduction of up to 98%. CelluForce, a leader in the production of nanocrystalline cellulose, took on the initiative also, and opened their first factory for the production and disposal of NC in 2012, in Canada.
How is NC produced?
The production of NC is a multi-step strategy, involving a series of purification processes followed by mechanical treatments and bacterial or chemical modifications on cellulose pulp. This results in nanometer-sized particles of cellulose, namely, cellulose nanofibrils (CNFs), cellulose nanocrystals (CNCs) and bacterial nanocellulose (BNC), as summarized in Figure 1.
The properties of nanocellulose:
The characteristics of NC determine its increasing interests and applications in different industries, such as packaging, paper, food, medical and hygiene products, cosmetics and optical sensors, are presented in Figure 2. Moreover, their structural properties and chemical changes (covalent bonding and electrostatic interactions) also play an important role in the production of packaging materials (which will be explained in detail in an upcoming article).
Applications of nanocellulose:
1. Biomedicine
From a biomedical viewpoint, NC, particularly of bacterial origin, commonly known as bacterial nanocellulose (BNC), attracts strong interest, as wound dressings or scaffold materials for tissue engineering and implants, because of their biocompatibility and high purity. Other important future uses of BNC include replacement of blood vessels (vascular graft), soft tissue and nucleus pulposus. Moreover, some intestinal disorders can be treated by tablets made of dry solid NC. Whilst in a powdered form, nanocellulose can be used as an excipient in pharmaceutical formulations. In the medical field, it can be used for antimicrobial films and water absorbent pads. The micro-sized particles of natural sources of cellulose has also made its way into dental applications and regenerative medicine.
2. Cosmetics
Nanocellulose, mainly cellulose fibrils or microfibrillated cellulose (MFC), can be used in a range of cosmetic products, as an anti-wrinkle agent. Having prepared more than 250 different formulations at Cosmacon GmbH, Mr. Rainer Kröpke says in his interview with Exilva:
“I think MFC is a new, innovative raw material, which is produced naturally and from sustainable forestry. I see much potential, especially when it comes to replacing synthetic raw materials.”
Additionally, the thickening and stabilizing properties of MFC serves its purpose well in sunscreen sprays as it gives the ‘non-dripping’ effect and also reduces the oiliness effect, leaving behind a non-oily skin appearance. It also acts as a composite coating agent in products tailored for nails, hair, eyebrows, and eyelashes. The MFC is also convenient for hair care products, improving the wet compatibility of hair.
3. Ultra-absorbent aerogels
Due to its high absorbency selection criterion and besides their use as potential oil absorbents, NC makes suitable application in the following products: tampons, sanitary napkins or wound dressings in the form of freeze-dried nanocellulose aerogels.
Commercial production of NC-based products:
Asia Nano Group, a Korean-based company, has developed a full line of NC-based cosmetic products. Mr. Kim, the Managing Director of Asia Nano Group, mentions that,
“NC, a vegetable organic material, contains more than 80% moisture and forms a water pool, which maintains the moisturizing effect on the skin to a greater extent.”
The NC-based moisturizing and brightening cosmetics are currently being exported as:
- NF moisture Nanocell Mask, Mist and Serum
- NF Posoo Mask
- NF White Day Soft Cream
Nippon Paper Crecia Co. Ltd is a Japanese paper manufacturing company that produces adult diapers, made from functional NC fibers. The company is promoting the advanced utilization of natural forest resources to produce NC fiber deodorant sheets that provide comfort to customers. The advantages of such products include:
- Avoiding gel blocking
- Enabling less fluff
- Thinner pads
- High water holding capacity
DeLeon Cosmetics, inspired by Juan Ponce deLeon’s search to discover the fountain of youth, was founded to develop cosmetic products using natural ingredients, exerting anti-aging properties. Based on the novel technology called nanohydration, all the products are manufactured in the USA, at their Tallahassee, Florida facility. The niche products available constitute eye, face and neck masks.
To sum up, nanocellulose is gaining much attention in various sectors, with commercial products already accessible to the global audience for purchase. Where else could nanocellulose be applicable?
Here’s how nanocellulose can be used in the packaging industry.
