Can Nanotechnology save the planet?
Ottilia Saxl, Founder of the Institute of Nanotechnology accuses governments of lack of leadership, verging on cowardice, in failing to act to cut CO2 emissions. She calls for urgent action now to curb today s excesses, and so prevent an impending environmental catastrophe that will certainly cause suffering and death. She describes a spectrum of nanotechnologies that could help measure and control these excesses, and make doing without less painful.
The astonishing front page of The Independent newspaper on the 2nd of January this year (2009) reveals that international environmental experts agree that efforts to cut CO2 emissions have failed, and that the deployment of new, and generally untried, technology is the only way to prevent global catastrophe.
To invoke the deployment of off-the-wall , untried, technologies on a massive scale, with unknown consequences, seems a highly dangerous get-out for global governments who have utterly failed to face up to the impending, man-made, environmental catastrophe that threatens the planet. It is a shocking indictment of the lack of willingness of almost all Governments to act in the interests of their citizens, preferring to continue with the status quo of greed and excess.
The threat to the planet is staring us in the face, but our ostrich-like Governments are unwilling to take action. So what has happened to all the promises made at Kyoto, and afterwards? Responsibility for making changes has been neatly transferred, along with guilt, from Governments to the individual citizen. But it is certainly not the individual citizen who should shoulder the blame for getting the world in, or out of, this mess which is the result of policies of successive governments who are still fixated on short term gain and big business interests. But Governments are telling us we should make individual changes to our lifestyles in order to save the planet . Eschewing plastic carrier bags or taking the bus occasionally instead of the car is not going to make any difference. Until the big policy decisions to protect the environment are made and implemented at the highest levels, nothing will change.
By not taking action to stop global warming, Governments are demonstrating a dereliction of duty. They are failing the stop use of fossil fuels, failing to limit population growth, failing to protect the rainforest the lungs of the earth, and failing to protect the earth s biodiversity. They continue to support growth, expansion, and unfair allocation of the world s resources, including food and fuel, to a disproportionate few, while continuing to actively wage wars (perhaps the most environmentally destructive activity of all!) to ensure this unequal distribution continues. In effect, our Governments are leading us by the nose into an abyss from which there may be no return.
Last ditch fixes vs appropriate technologies?
In this war for survival of the human race, high performing technologies that can support a massive reduction of pressure on the planet s environment and resources need to be utilised now. We cannot wait until a worsening situation leads to the proposed deployment of large-scale, radical and unproven technologies, whose consequences could be as frightful as the problems they are ostensibly being used to solve! The idea of pinning our future hopes on such schemes such as reducing sunlight levels by introducing particles into the upper atmosphere or the recent controversial experiment to take CO2 out of the air by scattering tons of iron particles on the ocean to stimulate the production of algal blooms, seem to be bordering on lunacy. But when situations become desperate, people may become a bit crazy. How much better to take sensible measures now. To this end, some useful nanotechnologies which are already being commercialized or near to market are described below, although these cannot take the place of reining back our excesses.
They are called useful technologies, because they will make a difference. For example, the current fashion for land-based wind turbines, embraced so enthusiastically by politicians, in the main are not useful, as their energy generation output is often much lower than predicted. Unfortunately this has meant that in the meantime some wild and beautiful landscapes will become turbine junk yards, paradoxically in the name of protecting the environment.
Some nanotechnologies offering real environmental benefits
Tapping into the sun
The fossil fuel we burn in our everyday lives is responsible for 44% of the carbon dioxide emitted annually and rising. The earth has an abundance of renewable energy, we are just very poor at harvesting it. Energy from sunlight is sufficient to meet our needs an amazing ten thousand times over. Energy derived from photovoltaic (PV) sources is currently the fastest growing renewable energy technology. Until now, solar cells have been expensive and their efficiency low, between 7% and 15%, but nanotechnology is enabling higher efficiency (up to 30%) and cheaper cells.
In the UK, 60% of our electricity is used in buildings, but over seven times more solar energy that we use falls on those buildings. A new kind of nanotechnology-based solar collector has been invented in the form of energy-collecting transparent blinds that can be used in homes and offices. This technology is being commercialized by a spin-out from Imperial College called Quantasol. The Quantasol Solarstructure comprises a double-glazed fa ade, between which are sandwiched blinds , actually made of lenses which track the sun and focus the light onto nano-inspired solar cells. The cells generate electricity with up to 30% efficiency. The system cuts out direct sunlight, reduces the need for air-conditioning, while allowing diffuse sunlight to penetrate the building and provide interior illumination. So there is no need to turn on the lights when the blinds are working. Sceptics note, these new solar collectors also work well in diffuse light, so are just as much use in less sunny climates.
Nanotechnology and energy storage
In order to utilize renewable energy effectively, the bugbear is efficient energy storage, an issue which still needs to be resolved. Nanotechnology is leading to batteries with greater capacities and faster discharge / recharge cycles that deliver more power. These benefits are achieved by coating the surface of an electrode with nanoparticles which increases its surface area, allowing more current to flow between the electrode and the chemicals inside the battery. This technique could increase the efficiency of hybrid vehicles by significantly reducing the weight of the batteries needed to provide adequate power. There is already an electricity powered motorcycle, the KillaCycle, reputed to reach 0-60 mph in less than one second, and pass a quarter mile at 168 mph after 7.824 seconds, using battery techniques based on nanotechnology.
Hydrogen fuel cells offer another way to generate electricity cleanly, and by some are considered to be one of the important energy generating technologies of the future. There have been many problems to be overcome to make fuel cells efficient, cost effective and practical. Nanotechnology is offering ways to meet these objectives and help take fuel cells out of the lab and into the real world. For example, nanoengineering of the hydrocarbon membranes are enabling fuel cells to be more efficient, while nanoscale structures adopted from the semiconductor industry are dramatically increasing the catalyst surface area, and expensive platinum catalysts are being replaced by less expensive nanomaterials. Already Honda has a production car, the FCX Clarity which uses fuel cell technology that depends on nanotechnology to improve its efficiency. Electricity is generated by combining stored hydrogen with oxygen from the air, and water vapour and heat are the only by-products.
Pollution monitoring and remediation
Although technology has made our lives easier in many ways, it has nearly always come at a huge environmental cost, for example, the extreme pollution caused by manufacturing processes and modern transportation. Presently we monitor levels of pollutants through using large, fixed devices which provide localised data, or require an operator to go to a location, take a sample and perform some type of analysis back in a laboratory. This is not satisfactory for responding rapidly to localised changes over a wide area. A far better system is one where sensors can be distributed widely, and that can detect and measure target pollutants from a number of points and automatically relay this information back to a central control. An example of a technology for monitoring air pollution in this way using nanotechnology has been developed by the JRC at Ispra, Italy. Based on nanostructured thin films of tin oxide, it is a solid state sensor able to detect nitrous oxides and carbon monoxide in a faster response time, it can be re-used and is much cheaper to run, cutting out the need for technicians and laboratories.
One example of how nanotechnology has provided a solution that no conventional technology comes close to matching, is in the removal of arsenic from groundwater. Whether as a result of natural leaching from bedrock or from industrial effluent, arsenic levels in groundwater in some areas in developing and developed countries breach WHO safety limits. A new technology which makes use of magnetic iron oxide nanoparticles, may provide the solution. Developed at Rice University in the USA and currently undergoing field trials in Mexico, 12nm iron oxide nanoparticles added to the effluent have been found to bind with over 99% of the arsenic in the water. By applying a magnetic field, the nanoparticles can be separated and simply removed from the water, which is then poured off.
Environmentally friendly solvents and anti-corrosion coatings
With regard to reducing pollution, the replacement of solvents is a good place to start. Most solvents are highly toxic, they pollute water courses and kill plants and animals, as well as causing serious health problems to humans. Nanotechnology is the basis of breakthroughs in new nanocoatings and nano structured surfaces that repel dirt and other contaminants, leading in some cases to a complete eradication of the need for solvents altogether. Surfaces can today be sprayed or painted with coatings which contain dispersed nanoparticles. These nanoparticles are specially functionalised , that is, they are chemically treated to acquire a particular attribute, such as dirt resistance, and are then incorporated into a carrier material to form a coating. Nanotechnology is also offering a new approach to the problems posed by corrosion. Corrosion accounts for a huge 3-4% of UK gross domestic product! Many anti-corrosion coatings contain chromium and cadmium - deadly substances which the EU is seeking to ban because of their impact on the environment, and their health and safety implications. Heavy users of these coatings, such as vehicle and component producers, are keen to find alternatives, as using and recycling of these toxic compounds is both costly and unpleasant.
Historically, corrosion was prevented by treating metal to produce a passive (mixed oxide) outer layer. Red lead was initially used, then chromate-based systems. Unfortunately, these are both toxic and carcinogenic. Red lead has been outlawed for years and now chromates are subject to environmental legislation, and are being banned for most applications. Research on developing environmentally friendly alternatives to these systems follows two approaches. One tries to mimic the self-repair mechanism of chromate treatments, e.g., molybdates, tungstates, vanadates; and the other incorporates a slow release inhibitor. The latter approach, adopted by Professor Robert Akid s research group based at Sheffield Hallam, encapsulates corrosion inhibitors within a sol gel matrix, with the aim of maintaining a balance between solubility and release rate of the inhibitor and the hydrophobic nature of the coating. This technology provides a slow release mechanism through inhibitor-containing coatings which produce a protective, passive film / diffusion barrier on the substrate, with no environmental downsides.
Nanofunctionalised polymers for the energy efficient extraction of gaseous pollutants
Volatile Organic Compounds (VOCs) and CO2 are liberated in huge volumes in the waste gas streams as the result of many industrial processes, and cause serious contamination of the environment. Around 24,000 million tonnes of CO2 alone are released per year worldwide, equivalent to 6,500 million tonnes of carbon annually, contributing dramatically to global warming. VOCs, as well as damaging the environment, pose a serious risk to human health. But not only does the loss of containment of VOCs from industrial processes threaten health - it also represents the loss of valuable resources. Being able to extract and re-use them is essential to many industries, including the food, beverage and dairy processing, chemical, pharmaceutical and oil/gas industries.
A completely new kind of pollutant extractor has been created by Dr Semali Perera and her team at Bath University. These extractors have much higher membrane area-to-volume ratios (>3000 m2/m3) than existing extractors. They are adsorbent, hollow fibres that have tiny pores less than 1,000th of the width of a human hair and contain nanomaterials which trap the VOCs and other gases and remove them from the air flow. This patented nanofibre technology is being commercialised through a new company, Nanoporous Solutions Ltd.
This development of these revolutionary molecular sieving devices also addresses a major area of concern in the extraction and recovery CO2 and VOCs pollutants the need for a cost effective technology. Conventional thermal oxidation processes presently used to clean process waste are usually energy hungry themselves, whereas the novel nano-porous fibre technology developed at Bath requires less than 5% of the energy used by these processes, offering great savings that could help reduce the environmental impact even further.
Conclusion
We are all depending on our Governments to pass legislation that ensures the future health of the planet, by immediately reining in the environmental damage being inflicted on the planet. They can be helped by the use of relevant new technologies, especially nanotechnology. As Geoffrey Sacks, the American economist, rightly put it: The problems confronting us require the application of new technologies on a scale to address the challenge. Those technologies exist, or can be developed, and public policies will be needed to get them into place . Urgently.
