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Nanotechnology Spotlight

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Showing Spotlights 17 - 24 of 99 in category Green Nanotechnology (newest first):


Novel nanoparticle synthesis method improves coatings for smart windows

smart_windowBuildings and other man-made structures consume as much as 30-40% of the primary energy in the world, mainly for heating, cooling, ventilation, and lighting. 'Smart' windows are expected to play a significant role in reducing the energy consumption of homes in two ways: by generating energy themselves; and by providing better insulation by allowing light in and keeping the heat out (in hot summers) or in (in cold winters). Vanadium dioxide (VO2) has long been recognized as a a material of significant technological interest for optics and electronics and a promising candidate for making 'smart' windows: it can transition from a transparent semiconductive state at low temperatures, allowing infrared radiation through, to an opaque metallic state at high temperatures, while still allowing visible light to get through. In new work, researchers have now offered a simple method for promoting the production of monoclinic VO2 nanoparticles by doping.

Posted: Aug 27th, 2012

Nanotechnology and the environment - Potential benefits and sustainability effects

environmentNanotechnology products, processes and applications have the potential to make important contributions to environmental and climate protection by helping save raw materials, energy and water as well as by reducing greenhouse gases and problematic wastes. Great hopes are being placed on nano-technologically optimized products and processes that are currently under development in the energy production and storage sectors. Emphasis is often placed on the sustainable potential of nanotechnology, but this in fact represents a poorly documented expectation. Determining a product's actual effect on the environment - both positive and negative - requires considering the entire life cycle from the production of the base materials to disposal at the end of its useful life. Not every 'nano-product' is a priori environmentally friendly or sustainable, and the production of nanomaterials often requires large amounts of energy, water and environmentally problematic chemicals.

Posted: Jul 11th, 2012

Solar-powered cement production without carbon dioxide emissions

betonwandThe global cement industry is currently one of the largest single emitter of carbon dioxide, generating on average about 830 kg of this greenhouse gas for each 1000 kg of cement produced. Considering that the worldwide annual production of cement is a whopping 3.8 trillion kg, the cement industry alone accounts for approximately 5-6% of man-made CO2 emissions. Researchers have now presented a solar-powered process to produce cement without any carbon dioxide. In their STEP (Solar Thermal Electrochemical Production) process, cement limestone undergoes low energy electrolysis to produce lime, O2 and reduced carbonate without carbon dioxide emission. In this new technique, the kiln limestone-to-lime process is replaced by an electrolysis process which changes the product of the reaction of the limestone as it is converted to lime.

Posted: Apr 11th, 2012

Nanobrick walls make excellent gas barriers and flame retardants

flamesPolyurethane (PU) foam is an extremely versatile material that commonly is used in bedding, upholstery and building insulation. However, PU foam is very flammable, often resulting in dripping of melted material that enhances flame spread through the formation of a pool fire under the burning object. Brominated flame retardant compounds (e.g. pentabromodiphenyl ether) have been used to reduce foam flammability but there is growing evidence that these chemicals are toxic to the environment and living organisms. Replacing brominated flame retardants in polymer formulations with safer and more environmentally-friendly alternatives has also sparked the interest of nanoscientists. One recent effort to create an environmentally-friendly flame retardant system involves the layer-by-layer assembly of thin films using materials obtained from completely renewable sources.

Posted: Mar 9th, 2012

A desalination battery for freshwater production

desalination_cellTechnological advances have made desalination and demineralization of seawater feasible, albeit expensive, solutions for increasing the world's supply of freshwater. Among various desalination technologies, reverse osmosis membranes have been widely used for water reclamation. However, external energy required and high operational pressure used (above 75 bar for reverse osmosis desalination and 25 bar for reverse osmosis water recovery from wastewater) make reverse osmosis membrane water reclamation processes energy intensive - not exactly an advantage given the rising cost of energy and the negative climate impact of fossil fuels. Researchers have now demonstrate the novel concept of a "desalination battery", which operates by performing cycles in reverse on our previously reported mixing entropy battery.

Posted: Feb 7th, 2012

Nanotechnology could make battery recycling economically attractive

batteriesMany batteries still contain heavy metals such as mercury, lead, cadmium, and nickel, which can contaminate the environment and pose a potential threat to human health when batteries are improperly disposed of. Not only do the billions upon billions of batteries in landfills pose an environmental problem, they also are a complete waste of a potential and cheap raw material. Unfortunately, current recycling methods for many battery types, especially the small consumer type ones, don't make sense from an economical point of view since the recycling costs exceed the recoverable metals value. Researchers in India have carried out research to address the recycling of consumer-type batteries. They report the recovery of pure zinc oxide nanoparticles from spent Zn-Mn dry alkaline batteries.

Posted: Dec 1st, 2011

This will take your breath away

breath_analysisBreath analysis has been recognized as an increasingly accurate diagnostic method to link specific gaseous components in human breath to medical conditions and exposure to chemical compounds. Sampling breath is also much less invasive than testing blood, can be done very quickly, and creates as good as no biohazard waste. A recent review article in Environmental Science and Technology focuses on breath analysis as a tool for assessing environmental exposure and provides a good overview of the current state of diagnostic tools, leading studies in this field, and emerging technologies for hand-held breath analyzers. After describing the basics of breath analysis as a diagnostic tool, the authors discuss emerging chemical sensor technology ('electronic noses'), in particular two nanotechnology-based approaches, that are suitable to identify target analytes in breath.

Posted: Oct 24th, 2011

New nanomaterials for radioactive waste clean-up in water

nanofibersBack in 2008 we reported on nanotechnology solution for radioactive waste cleanup, specifically the use of titanate nanofibers as absorbents for the removal of radioactive ions from water. Now, the same group that developed these nanomaterials reports in a new study that the unique structural properties of titanate nanotubes and nanofibers make them superior materials for removal of radioactive cesium and iodine ions in water. Based on their earlier work, the researchers have now demonstrated a potentially cost-effective method to remediate cesium and iodine ions from contaminated water by using the unique chemistry of titanate nanotubes and nanofibers to chemisorb these ions.

Posted: Oct 4th, 2011