Nanocellulose, or microfibrillated cellulose (MFC), is a material composed of nanosized cellulose fibrils with a high aspect ratio (length to width ratio). Typical lateral dimensions are 5–20 nanometers and longitudinal dimension is in a wide range from tens of nanometers to several micrometers. It is pseudo-plastic and exhibits the property of certain gels or fluids that are thick (viscous) under normal conditions, but flow (become thin, less viscous) over time when shaken, agitated, or otherwise stressed. This property is known as thixotropy. When the shearing forces are removed the gel regains much of its original state. The fibrils are isolated from any cellulose containing source including wood-based fibers (pulp fibers) through high-pressure, high temperature and high velocity impact homogenization.
Nanocellulose can also be obtained from native fibers by an acid hydrolysis, giving rise to highly crystalline and rigid nanoparticles (generally referred to as nanowhiskers) which are shorter (100s to 1000 nanometers) than the nanofibrils obtained through the homogenization route. The resulting material is known as nanocrystalline cellulose
Paper and paperboard:
There is potential of nanocellulose applications in the area of paper and paperboard manufacture.[citation needed] Nanocelluloses are expected to enhance the fiber-fiber bond strength and, hence, have a strong reinforcement effect on paper materials. Nanocellulose may be useful as a barrier in grease-proof type of papers and as a wet-end additive to enhance retention, dry and wet strength in commodity type of paper and board products.
Composite:
As described above the properties of the nanocellulose makes an interesting material for reinforcing plastics. Nanocellulose has been reported to improve the mechanical properties of, for example, thermosetting resins, starch-based matrixes, soy protein, rubber latex, poly(lactide). The composite applications may be for use as coatings and films, paints, foams, packaging.
Food:
Nanocellulose can be used as a low calorie replacement for today’s carbohydrate additives used as thickeners, flavour carriers and suspension stabilizers in a wide variety of food products and is useful for producing fillings, crushes, chips, wafers, soups, gravies, puddings etc. The food applications were early recognised as a highly interesting application field for nanocellulose due to the rheological behaviour of the nanocellulose gel.
Hygiene and absorbent products:
Different applications in this field include:
Super water absorbent (e.g. for incontinence pads material)
Nanocellulose used together with super absorbent polymers
Use of nanocellulose in tissue, non-woven products or absorbent structures
Use as antimicrobial films
Emulsion and dispersion:
Apart from the numerous applications in the area of food additives, the general area of emulsion and dispersion applications in other fields has also received some attention.[42][43] Oil in water applications were early recognized. The area of non-settling suspensions for pumping sand, coal as well as paints and drilling muds was also explored by the early investigators.
Oil recovery
Hydrocarbon fracturing of oil-bearing formations is a potentially interesting and large-scale application. Nanocellulose has been suggested for use in oil recovery applications as a fracturing fluid. Drilling muds based on nanocellulose have also been suggested.
Medical, cosmetic and pharmaceutical[edit source:
The use of nanocellulose in cosmetics and pharmaceuticals was also early recognized. A wide range of high-end applications have been suggested:
Freeze-dried nanocellulose aerogels used in sanitary napkins, tampons, diapers or as wound dressing
The use of nanocellulose as a composite coating agent in cosmetics e.g. for hair, eyelashes, eyebrows or nails
A dry solid nanocellulose composition in the form of tablets for treating intestinal orders
Nanocellulose films for screening of biological compounds and nucleic acids encoding a biological compound
Filter medium partly based on nanocellulose for leukocyte free blood transfusion
A buccodental formulation, comprising nanocellulose and a polyhydroxylated organic compound
Powdered nanocellulose has also been suggested as an excipient in pharmaceutical compositions
nanocellulose in compositions of a photoreactive noxious substance purging agent
Elastic cryo-structured gels for potential biomedical and biotechnological applications.
Other applications:
Activate the dissolution of cellulose in different solvents
Regenerated cellulose products, such as fibers films, cellulose derivatives
Tobacco filter additive
Organometallic modified nanocellulose in battery separators
Reinforcement of conductive materials
Loud-speaker membranes
High-flux membranes
Flexible electronic displays[7]
Computer components[7]
Lightweight body armour and ballistic glass[7]
