Nanocrystalline cellulose (NCC), which is produced by processing wood pulp, is being hailed as the latest wonder material. Japan-based Pioneer Electronics is applying it to the next generation of flexible electronic displays. IBM is using it to create components for computers. Even the US army is getting in on the act, using it to make lightweight body armour and ballistic glass.
So why all the fuss? Well, not only is NCC transparent but it is made from a tightly packed array of needle-like crystals which have a strength-to-weight ratio that is eight times better than stainless steel. Even better, it's incredibly cheap.
What’s brown and sticky, lightweight, flexible, stronger than steel, stiffer than Kevlar, and conducts electricity? Nanocellulose. Oh, isn’t actually brown and sticky either: it’s transparent.
Nanocellulose is a new wonder material that is simply plant matter that has been carefully smashed to pieces, and then reformed into neatly-woven nanoscale crystals and fibers. You generally start with wood pulp, remove any non-cellulose impurities (such as lignin) using a homogenizer, and then gently beat the mixture to separate each of the cellulose fibers. Depending on the exact process used, these fibers then form into a thick paste (pictured above) of needle-like crystals (2nm wide, hundreds of nanometers long, below left), or a spaghetti-like structure of cellulose fibrils (below right).
Nanocellulose or microfibrillated cellulose (MFC), is a material composed of nanosizedcellulose 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 10s of nanometers to several microns. It is pseudo-plastic. Moreover, nanocellulose 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 (see manufacture below). 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.
A leader in wood products research for over a century, the FPL is positioning itself to become the lead Federal research facility for the application of nanotechnology in forest products. Using structural, chemical, and mechanical evaluation techniques, interdisciplinary teams of scientists continue to expand FPL's nanotechnology research program.