Nano materials go for high tonnage

A UK government sponsored mission to Russia and the Ukraine found that research into advanced materials based on nano size powders is not only alive and well but now being transferred into significant commercial areas. Almost all the research started out as adjuncts to the Soviet defence programmes in the Cold War, and went under a cloud as the countries of the former Soviet Union re-oriented themselves, but it has lately been re-financed and re-vitalised and is now squarely aimed at commercial markets. Some efforts remain in aerospace, and US companies have been quick to form alliances there, while other applications are in micro-surgical implements, human skull repairs, fuel cells, hydrogen storage, sensors, solar cells and a clever device that helps cold starting motor vehicles, very relevant to the move to biofuels. The mission was organised by the Impact Faraday Partnership with the support of the DTI. The amount of information presented at the reporting DTI Global Watch Seminar was overwhelming, but highlights have to include capability to produce of nano particles in tonnage quantities and some of the applications. The largest production unit seen was an industrial plasma reactor at the A.A.Baikov Institute for Metallurgy and Material Science in Moscow, who had built a 250kW monster capable of producing 30 to 50 kg/h of ultrafine tungsten powder. They are also able to make ultrafine metal powders: nickel, iron, copper, molybdenum, cobalt, niobium and tantalum as well as carbides, carbo nitrides, oxides and coated powders: alumina-tungsten, zirconia-tungsten, and tungsten-copper. From these, they can make various kinds of metal-carbon and metal-ceramic composites. For those who wish to manufacture these very fine powders themselves in order to product their own exotic composite materials, the Institute for Problems in Chemical Physics in Chernogolovka, Moscow Region has started manufacturing small scale, plasma chemical production units for sale. The 'Migen' microwave generator units use a 5kW power supply and produce 100g/hour of particles about 10nm across. Because the particles are very reactive, the Institute has developed its own purification system, which allows it to use normal commercial gases. A number of units have been supplied to customers in China, Hong Kong, Taiwan and India despite their 250,000 euro price tag. Follow up technical service is provided and construction and installation takes about a year. They can be used to make powders of metals, oxides, nitrides, carbo nitrides and more complex combinations such as: Titanium-vanadium-nitride, niobium-titanium-carbo-nitride, titanium nitride plus molybdenum, and Titanium Nitride plus tungsten. Another technique which seems to be popular in Russia and the Ukraine is self propagating high temperature synthesis or SHS. The technique was discovered in 1967 as a result of investigating the mechanisms of thermite welding. The process consists of igniting the top of a cylinder of reactants, which produces sufficient heat of reaction to propagate the process down through the block. More than 500 systems have been studied at the Institute of Structural Macrokinetics and Materials Science (ISMAN), also in Chernogolovka. The technique has apparently been used to produce submicron boron nitride for use in cosmetic face powders and ceramic water purification filters that have acid and temperature resistance plus bactericide activity. They are said to be easily regenerated. In conjunction with the Institute of Petroleum, the Institute is developing catalyst supports with high surface areas. On the other hand, by undertaking SLS under pressure, it is possible to produce dense ceramic and hard alloyed items, while 'Centrifugal SHS' can be used for the magnetron spraying of a range of composite materials for use in abrasive devices. SHS powders and products are presently being produced in Salamanca, Spain by SHS Ceramicas: a joint venture between ISMAN and the Spanish company, ENUSA. The company currently produces silicon nitride, boron nitride and magnesium sulphate heptahydrate. Other reported manufacturing methods to produce nano powders included: grinding, wet chemistry, emulsification, aerogel recitation, microwave treatments, gas flames, ultrasound, shock waves and exploding wires. Another ceramic application is the use by the Franstevich Institute for Problems in Materials Science in Kyiv in the Ukraine of tough zirconia based ceramics to repair the skull of a dog, which, apparently has also been used to repair the skull of a soldier shattered by a sniper in Afghanistan. Nano crystalline hydroxyapatite is a bioactive stimulator of bone tissue growth. A water slurry moulding process, followed by cold isostatic pressing and low temperature sintering is used to shape and provide a highly polished surface for the repair implant. Also based in Kyiv, the V.I.Vernadskii Institute of General and Inorganic Chemistry has developed novel positive temperature coefficient resistors that depend on 200nm sized particles of yttrium titanium oxide to preheat cold car and truck engines. The advantage of PTCR devices is that they are self regulating, requiring no electronic control yet maintain their design operating temperature regardless of both ambient temperature and supply voltage. They reduce the minimum temperatures at which engines may be started by 10 deg C when relying on vehicles batteries, or 15 to 20 deg C if powered from outside. While the desirability of such technology is obvious in the bitter winters of Russia and the Ukraine, it is also of immense potential usefulness for diesel engines run on vegetable oil, a growing fashion in the US, which require that the vegetable oil be heated sufficiently to have a viscosity no higher than that of cold, conventional diesel fuel. The PTCR effect occurs when two conditions are met: a phase transition occurs, such as from ferroelectric to paraelectric, and individual grains in polycrystalline materials have to have semiconducting properties while grain boundaries have to have dielectric properties. The Kharkiv Institute of Physics and Technology, also in the Ukraine, on the other hand, has applied its nano technology to the production of ultra fine grained tantalum, titanium and stainless steel medical applicators, oncology needles and bilayer stents. They also have a technology, developed and patented with Dr R Forbes at the University of Surrey School of Electronics and Dr N Wanderka at the Hahn Meitner Institute in Berlin to produce ultra smooth, shaped surfaces for ultra sharp surgical instruments and probes for scanning tunnelling microscopes. The technique involves the field evaporation in a dielectric medium, either liquid or gas. IMPACT Faraday DTI Global Watch Service International Technology Promoter IMPACT Faraday DTI Global Watch Service International Technology Promoter A.A.Baikov Institute of Metallurgy and Materials Science. Institute of Problems in Chemical Physics Institute of Structural Macrokinetics and Materials Science Franstevich Institute for Problems in Materials Science V.I.Vernadskii Institute of General and Inorganic Chemistry Kharkiv Institute of Physics and Technology Eureka says: The range and scope of nano materials research and development in Russia and the Ukraine is vast, and it is a little worrying that the customer countries most eager to embrace it are all our industrial competitors or potential competitors Pointers * Nano powders of many useful metals, ceramics and combined substances can be produced in up to tonnage quantities by a variety of techniques * Applications are mainly in aerospace and medical, but also in automotive * Everything is for sale or licence. The days of the dominance of secretive Soviet defence oriented research are long gone