Within the fibre and fabric industry, there can be no discipline as exciting, fast-developing or potentially world-changing as nanotechnology.
Concerned with the use of materials of one to 100 nanometres in size (one nanometre being one billionth of a metre), nanotechnology holds the key to the next generation of performance clothing and has applications at all stages of production, from treating raw materials to producing woven fabrics and finishing.
In fact, the area is expanding so rapidly that while nanotechnology products in the global market were worth $13 billion in 2004, the Nanobusiness Alliance predicts that they will reach $2.6 trillion in 2014.
Brian McCarthy, managing director of the not-for-profit research organisation TechniTex Faraday Partnership, said: "It's a hugely important area for the future of textiles - there's a constant pressure to deliver products that are of good quality but low cost and nanotechnology could be the key to that."
Nanotechnology for health products
Although nanotechnology-enhanced garments, accessories and fabrics are still in their infancy, there are already several products on the market.
For example, nanotechnology filter masks are available that use closely-placed nano-sized particles to trap contaminants as small as pollen and bird flu viruses. Some also come with eradicating agents that can kill viruses and other potential sources of infection.
Another healthcare-related nanotechnology solution, and one that is probably better known, is nanosilver. Silver has always had inherently antibacterial properties, but until nanotechnology came along it was difficult to implement.
Brian explained: "The problem with silver threads is that they get dispersed into the middle of the fabric, where they won't come into contact with the bacteria. But with nanosilver, you can arrange for the nano-sized grains to be distributed directly onto the surface of the clothing where they need to be."
"The nanosilver particles stay on the fabric itself thanks to ionic bonding, in which an electrostatic pull keeps the two atoms together. This ensures that the silver stays on the material through both wear and washing."
Nanotechnology in transport
Nano-sized particles are helping save lives outside of hospitals, too - some car door panels, for example, use 'nanoclays' in their textile coverings to reduce flammability. One type of nanoclay is montmorillonite clay, which is produced by volcanoes and forms sheets that are just one molecule thick.
Brian said: "Nanoclays are used as an integral part of the material and provide an added flame retardancy. They also make the materials lighter, so when used in automobiles obviously leads to savings in fuel.
"They are currently used by Toyota, as well as other car manufacturers, and I'm sure that people are already looking at possible applications for clothing."
The lotus effect
One nano development that can definitely find a use in clothing is 'the lotus effect'. In nature, lotus plants use a unique surface structure to repel water. Thus, when they are splashed or caught in rain, the droplets roll off like mercury, taking dirt, insects and other items with them.
With this in mind, companies are now developing nano-thin coatings for textiles that cause them to mimic lotus leaves, ensuring that whatever textile they are applied to remains perfectly dry an easy to clean.
Nano-based chemical coatings are already being marketed and one additional advantage that they bring is that their thinness ensures that the feel and handle of the textile is not affected.
Such nano-thin layers are created using plasma treatments. During this process, a special gas has one or more of its electrons - subatomic particles that are the building blocks of molecules - disassociated from it, making it electrically conductive.
This conductive form is known as plasma. The plasma energises the surface of the fibre and causes it to also lose electrons. This means that when the chemical finish is added, the textile molecules attract the chemical molecules and they begin to share electrons.
In this way, an ionic bond - an electrical attraction - is created between their molecules. This bond is strong enough that it will withstand the usual wear and washing cycles. It also means that the chemical molecules are dispersed evenly over the surface - one for each textile molecule.
There are some slightly flashier and more impressive uses for nanotechnology, however - most notably the current advances in smart textiles.
The previous generation of smart textiles, of course, relied on inbuilt wires and circuitry that had to be removed before washing the garment - something that was hardly practical for most people.
But Brian says that modern smart textile garments are rather more advanced.
"The current generation doesn't use wires at all - by incorporating metals in nanoparticle form, it is possible to create conductive fibres that run through the fabric of the clothing," he explained.
"These kinds of nanotextiles are the key thing in the short-to-medium term for nanotechnology because improving the performance of the garment's fibres allows the incorporation of various new sensors and electronics - that will be the next generation."
Dyeing at a nano level
Other nanotechnology applications that are still in development include nanodyeing. One of the difficulties of the traditional dyeing process is that sometimes dyes can clump together, creating uneven colouration and wasting time and money.
However, new developments in nanotech may make this problem a thing of the past: "Scientists have found a way to make carbon black dye particles self-disperse," said Brian. "This leads to a regular finish and gets rid of the problem of dyestuffs clumping into granules.
"There's going to be a lot of interest in the self-dispersing dyes because it will lead to mass dye usage with more uniform colouration. It will hopefully also lead to more environmentally-safe processing."
More unusually, nanotech developers are currently working on disposable wipes that can detect dangerous bacteria and diseases.
Brian said: "There's some work over in the United States where they're binding antibodies onto nanofibres in cloths that can then be wiped over anything that may be infected. Each of the antibodies will react to a different target and latch onto it.
"What they don't have yet is any way for the wipe to self-report. That would probably mean implementing something that would cause the cloth to change colour when in contact with a contaminant."
Once this product is up and running, people with no technical training at all will be able to check areas for dangerous pathogens and institute a cleaning regime quickly and easily.
Nanotubes for strengthened fibres
One last piece of in-progress nanotechnology research is the quest to develop a way to make carbon nanotubes grow faster.
Carbon nanotubes are essentially what they sound like - cylinders whose walls are made of a sheet of one-atom-thick carbon. Despite their size, their molecular makeup means that they are incredibly strong - and that has definite benefits for fibre manufacturers.
Brian explained: "The tubes can be incorporated into a conventional polymer to make a single fibre with two different components.
"The carbon nanotubes provide their strength and the synthetic fibres provide their natural properties. It will have the handle of a conventional polyester or polypropylene, but with added strength.
"The simplest way of making the tubes is growing them in a furnace - you put in an organic base at a very high temperature and the carbon then grows like crystal.
"However, this is very slow and there are a number of plans to speed up the process because once you can grow it fast, the whole economics the process will change. They can increase the process of production tenfold."
Currently, the best chance of improving speed looks to be electro-spinning, and universities across the world are currently looking into ways of improving the process.
Electro-spinning works by squeezing a suitable substance through an electrified needle; the voltage causes it to stretch out and whip around in a spiral formation until it is nano-thin; it is then collected on a grounded plate.
Moulding the future
With the entire industry being a hive of technological development, nanotechnology really needs some rules and boundaries. Thankfully, according to Brian these are already well underway.
"Early last year, the British Standards Institute came up with the first definitions of what nanoparticles are. That's crucial to have in place," he said. "The next stage is to apply the initial general definitions to textiles and hopefully that's what will happen soon.
"Also, as we speak, a British Standards Committee is being formed on smart textiles to think about the areas where standardisation is required. That really is a sign of the industry maturing and saying that we now need a common standard platform for manufacture."
Other organisations are also working to create standards for nanotechnology; the Hohenstein Institute in Germany released its own nanotechnology quality label in 2005 and last year ITV Denkendorf introduced its quality label for products claiming to use the lotus effect.
The international race for nanotech supremacy
The European Union is also showing a great deal of interest in nanotech, and Brian believes that Framework Seven, the next round of EU R&D grants worth a total of €50 billion, will be their chance to give Europe the global advantage.
He said: "Over the course of five to six years there will be calls for collaborative projects for companies throughout Europe, although the collaboration must have two or three EU members."
He added that their interest is due in part to China, which is threatening to become the world's main source of nanotech development.
In fact, the Chinese Government has announced that a large amount of their manufacturing industry will be based on nanotechnology and with a hoard of money from foreign investments in their existing textile industry, they have enough money to make it work.
Already the numbers of Chinese nanotech papers has increased dramatically in the past decade - a 27-fold increase that has put them in second place behind the US for papers published inScience Citation Index.
But whatever tomorrow's world, one thing is certain - that nanotechnology will be a vitally important part of it.
Author: James Wilkinson
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