Nanofibers - Revolutionary Material for the 3rd Millennium
Nanofiber market will be the fastest emerging market in the next decade, analysts say.
Nanofibers belong to the world of nanomaterials; their diameter varies in the range of tens to hundreds of nanometers. Thanks to their structure, nanofibrous materials have unique properties and offer unexpected opportunities for their use in many areas.
Nanofiber is so small and light that just over one gram would be enough to circle the world round the equator.
Thanks to such features as
- enormous specific surface area
- high porosity
- small pore size
- the diameter of fibers
the use of nanofibers can be anticipated in many new products.
strength, reactivity, electrical and optical quality, permeability of layers, which means that they have huge potential for such applications as energy conversion and storage, liquid and air filtration, food and packaging, health and personal care and environmental protection.
Nanofibers offer immense opportunities for creating products with new properties, as they enable the modification or functionalization of a nanofibrous layer using various chemical or physical processes during or following the production process. Functionalization can significantly improve surface properties, creating for example super-hydrophobic (water repellent) or super-hydrophilic (highly water absorbent) materials. The uniformity of nanofibrous layers, their thinness and high permeability make them a crucial material for many industries.
Nanofibers can be produced in a number of ways, such as electrospinning, melt spinning, self-assembly, template synthesis, electroblowing, forcespinning, etc.
At present the only method of producing nanofibers on industrial scale is electrospinning, which uses a polymer solution as the source for creating nanofibers and a high electric voltage. Breakthroughs in nanofiber spinning equipment manufacturers, the most widely used of which is the Nanospider technology made by the Elmarco company, have enabled significant improvement in machinery performance and have thus created the potential for use in many spheres of industry.
The properties of nanofibers significantly depend upon the material from which they are made. Currently nanofibers can be produced on an industrial scale from dozens of polymers including biocompatible (which can withstand the biological environment) or environmentally friendly biodegradable polymers.
Nanofibers can change the properties of a range of materials or even enable the creation of entirely new materials. They have a wide range of uses. At present they are most often used in air filtration, where they are very effective in removing submicron particles, including viruses and bacteria. Their high filtration efficiency does not change over time, as in the case of electrically charged filters, while the energy consumption necessary for filtration is much lower than those commonly used filters. Membranes for nanofiltration can separate molecules from the size between 0.5 and 10 nm.
Nanofibers and business
Nanofibers offer hope in finding solutions for fundamental problems in the development of human society – the cleaning and production of drinking water, mobile sources of energy, batteries enabling advanced energy storage. These are problems which directly concern millions of people. Further development in these regions is dependent upon solutions being found, and this huge potential demand represents a great business opportunity. Demand for products containing nanofibers is expected to grow by as much as 40%.
The business potential of nanofibers is further enhanced by the fact that, unlike nanoparticles, nanofibers with dimensions over 100 nm are not regulated, even in the EU, and are potentially suitable for use in the food industry or for direct contact with foodstuffs.
The history of nanofibers
The first attempts at nanofiber production were carried out between 1934 and 1944. A. Formhals published the first patent at this time describing the experimental production of nanofibers. The next step was taken in 1966 by Professor Harold L. Simons, who patented an instrument for producing ultra-thin and ultra-light nanofiber fabrics with various patterns. In 1971 Professor Peter K Baumgartner made a device for the electrospinning of acrylic fibers with a diameter of 0.05 – 1.1 microns. The work of these inventors, and in particular their followers Professors Darrell Reneker, Iksoo Chun, L. Larrond and R.St. John Manley has been continued by the team of Professor Oldřich Jirsák from the Technical University in Liberec.
The first technology enabling the production of nanofibers appeared on the global market in the 1980s. Donaldson, one of the leading companies in nanofibers based applications brought out the nanofibers first time for advanced commercial applications such as air filtration technology–Ultra-Web® in 1981. The nanofibers presence showed a promise in reducing operating costs and improved efficiency.
From then until today, nanofibers technology has benefited numerous industries including filtration, transportation, construction, agriculture, mining, military and gas turbine. The full potential of nanofibers technology has yet to be realized in commercial domains. Recent developments in nanofibers production technology has opened up the possibilities of applying nanofibers for various process improvements. In 2005, the company Elmarco made a major breakthrough with the launch of the NanospiderTM, the first technology in the world to enable nanofiber production on an industrial scale. Major nanofibers innovations and inventions from research laboratories are in the lead for commercialization to play crucial part in industrial economy.