THE hottest new material in town is light, strong and conducts electricity. What's more, it's been around a long, long time.
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.
To ramp up production, the US opened its first NCC factory
in Madison, Wisconsin, on 26 July, marking the rise of what the US
National Science Foundation predicts will become a $600 billion industry
by 2020.
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.
"It is the natural, renewable version of a carbon nanotube at a fraction of the price," says Jeff Youngblood of Purdue University's NanoForestry Institute in West Lafayette, Indiana.
The $1.7 million factory, which is owned by the US Forest Service, will produce two types of NCC: crystals and fibrils.
Production of NCC starts with
"purified" wood, which has had compounds such as lignin and
hemicellulose removed. It is then milled into a pulp and hydrolysed in
acid to remove impurities before being separated and concentrated as
crystals into a thick paste that can be applied to surfaces as a
laminate or processed into strands, forming nanofibrils. These are hard,
dense and tough, and can be forced into different shapes and sizes.
When freeze-dried, the material is lightweight, absorbent and good at
insulating.
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