Nanotechnology is based on exploiting the experimentally observed and analysed changes which occur in materials when their physical sizes are shrunk to between 100 – 1 nanometres ( a nanometre is 1 billionth – 10-9- of a metre). These changes are seen as variations, at times drastic, in the chemical and physical properties of a material at the nanoscale compared to the bulk scale, where one can see, touch and feel a material.
A dramatic example of this is carbon in its elemental form. For centuries it was thought that carbon only existed in two solid forms, diamond, where carbon atoms are arranged in a cubic structure, or graphite, where carbon atoms are arranged in a flat sheet like structure and stacked on top of each other. Then in 1985 it was discovered that at about 1 nanometre diametre carbon atoms are arranged not as in diamond or graphite but rather in a sphere like a football! This football form of carbon, which was given the name Fullerene by those who discovered it, can form a solid made up of 1 nanometre carbon spheres ordered in a three dimensional structure (a crystal termed Fullerite) which is a radically different form of carbon compared to diamond or graphite. Its chemical properties are determined by the football structure which carbon atoms take up at the nanometre scale.
A dramatic example of this is carbon in its elemental form. For centuries it was thought that carbon only existed in two solid forms, diamond, where carbon atoms are arranged in a cubic structure, or graphite, where carbon atoms are arranged in a flat sheet like structure and stacked on top of each other. Then in 1985 it was discovered that at about 1 nanometre diametre carbon atoms are arranged not as in diamond or graphite but rather in a sphere like a football! This football form of carbon, which was given the name Fullerene by those who discovered it, can form a solid made up of 1 nanometre carbon spheres ordered in a three dimensional structure (a crystal termed Fullerite) which is a radically different form of carbon compared to diamond or graphite. Its chemical properties are determined by the football structure which carbon atoms take up at the nanometre scale.
The stable solid structures of elemental carbon which were commonly thought to occur naturally: a) Diamond b) Graphite and the new forms of stable solid carbon structures found to occur at the nanoscale) c) Spherical C60 (Buckminsterfullerene) – sphere diameter ~ 1nm and d) Single-walled carbon nanotube – tube diameter 5 – 1.3 nm.
Six years after the discovery of ‘football carbon’ it was observed that when the sheet structure of graphite is reduced to a strip in width below 100 nanometres it rolls up to form a tube. It was then discovered that in this tube form the electrical properties of graphite can change from being like a metal to a semiconductor, the property required to make transistors for electronics. This fundamental discovery of a change in the electronic properties of carbon at the nanoscale in turn enables, for example, a new technology of having transistors for electronic circuits made from carbon rather than silicon as at present. This is what would be termed a nanotechnology. Prior to the discovery about the behaviour of carbon at the nanoscale it was thought impossible for it to be considered as a replacement for silicon in electronics. How far we have leaped in our understanding and ambition over the past twenty years is evidenced by the commencement last week of a European Flagship Project, worth 1 billion Euro over a ten year period, which has at its core the development of carbon, in the form a single sheet of graphite shrunk to nanometre scales termed graphene, for electronics.
More generally when a material is reduced in size to the nanometre scale the proportion of atoms on the surface compared to those in the interior volume increase. This proportional increase in the surface atoms means that the chemical reactivity of a material, since all chemical reactions with other elements have to start from the atoms exposed on a surface, increases rapidly in proportion to its volume as the material is reduced to the nanoscale. This translates into having the same chemical action with vastly reduced amounts of material. The sheer act of making materials at the nanoscale and deploying them in chemical processes reduces the amount of material required. A fundamental feature of nanotechnology is therefore the ability ‘to do more with less’. It is in this context that for countries such as Sri Lanka where the industrial base is still developing that nanotechnology becomes strategically important, even essential, in manufacturing products which are globally competitive.
More generally when a material is reduced in size to the nanometre scale the proportion of atoms on the surface compared to those in the interior volume increase. This proportional increase in the surface atoms means that the chemical reactivity of a material, since all chemical reactions with other elements have to start from the atoms exposed on a surface, increases rapidly in proportion to its volume as the material is reduced to the nanoscale. This translates into having the same chemical action with vastly reduced amounts of material. The sheer act of making materials at the nanoscale and deploying them in chemical processes reduces the amount of material required. A fundamental feature of nanotechnology is therefore the ability ‘to do more with less’. It is in this context that for countries such as Sri Lanka where the industrial base is still developing that nanotechnology becomes strategically important, even essential, in manufacturing products which are globally competitive.
What are we doing in Sri Lanka?
" In Sri Lanka the focus is on synthesising nanomaterials chemically and reducing materials to the nanoscale through physical processes with a view to applying them in enhancing the performance and value of ‘Made in Sri Lanka’ products "
The focus of nanotechnology research and application is at the Sri Lanka Institute of Nanotechnology (SLINTEC) which is a partnership between the GoSL and six private sector companies. In addition SLINTEC is engaged with a further ten Sri Lankan companies in developing and exploring new nanotechnology based products. As part of its portfolio of research for the GoSL it is developing processes for converting and applying minerals found in Sri Lanka (Ilmenite, clay, magnetite, quartz, graphite, monazite) at the nanoscale to increase their value. All SLINTEC laboratories and research activities are housed within the new purpose built National Centre of Excellence in Nanotechnology (NCEN) at Homagama.
Nationally there are additional research projects in nanotechnology at the Universities of Peradeniya, Colombo, Sri Jaywardanepura, Moratuwa, Kelaniya , Jaffna and Ruhuna, and the Institutes of Industrial Technology (ITI) and Fundamental Studies (IFS). The facilities at NCEN can be accessed by all Sri Lankan universities and institutes for nanotechnology research. SLINTEC has collaborative research programmes with a number of Universities and National Research and Development Institutes (Rice, Rubber, Horticultural).
In the private sector Hybrid Technologies is a start up company which is commercialising new products which exploit the benefits of nanotechnology. One of its notable successes has been the introduction of the air purifying compact fluorescent light bulb. Here nanoscale titanium dioxide particles are used on the bulb surface to drive photocatalytic reactions in the surrounding air which kills organisms and reduces volatile organic compounds. It has gained wide scale interest for use in hospitals where patients are susceptible to hospital borne ‘super bug’ infections. An analogous product which uses titanium dioxide nanoparticles on garments to remove stains without washing has been developed at SLINTEC in collaboration with a major Sri Lankan apparel company.
SLINTEC has also patented a number of new inventions in nanotechnology. One of its notable successes has been the deployment of its patents relating to plant nutrients under commercial terms with a major Indian fertilizer company having manufacturing facilities in India, Africa and Latin America. The invention relates to using nanoparticles as a carrier for fertilizer, in particular urea, in order to reduce the rate at which it is dissolved in soil. Field trials carried out at the Rice Research and Development Institute at Batalagoda show that when urea is used in the new nanotechnology form the amount of fertilizer used can be halved with the rice yield per hectare remaining the same or in some cases increasing by 10%. This is a stunning example of ‘Doing More with Less’ through ‘Nanotechnology Made in Sri Lanka’!
Nationally there are additional research projects in nanotechnology at the Universities of Peradeniya, Colombo, Sri Jaywardanepura, Moratuwa, Kelaniya , Jaffna and Ruhuna, and the Institutes of Industrial Technology (ITI) and Fundamental Studies (IFS). The facilities at NCEN can be accessed by all Sri Lankan universities and institutes for nanotechnology research. SLINTEC has collaborative research programmes with a number of Universities and National Research and Development Institutes (Rice, Rubber, Horticultural).
In the private sector Hybrid Technologies is a start up company which is commercialising new products which exploit the benefits of nanotechnology. One of its notable successes has been the introduction of the air purifying compact fluorescent light bulb. Here nanoscale titanium dioxide particles are used on the bulb surface to drive photocatalytic reactions in the surrounding air which kills organisms and reduces volatile organic compounds. It has gained wide scale interest for use in hospitals where patients are susceptible to hospital borne ‘super bug’ infections. An analogous product which uses titanium dioxide nanoparticles on garments to remove stains without washing has been developed at SLINTEC in collaboration with a major Sri Lankan apparel company.
SLINTEC has also patented a number of new inventions in nanotechnology. One of its notable successes has been the deployment of its patents relating to plant nutrients under commercial terms with a major Indian fertilizer company having manufacturing facilities in India, Africa and Latin America. The invention relates to using nanoparticles as a carrier for fertilizer, in particular urea, in order to reduce the rate at which it is dissolved in soil. Field trials carried out at the Rice Research and Development Institute at Batalagoda show that when urea is used in the new nanotechnology form the amount of fertilizer used can be halved with the rice yield per hectare remaining the same or in some cases increasing by 10%. This is a stunning example of ‘Doing More with Less’ through ‘Nanotechnology Made in Sri Lanka’!