Monthly Archives: November 2012

New Take on Green, Clean Clothes

The award-winning British designer Helen Storey joined Tony Ryan a University of Sheffield scientist, to create a laundry additive that has the capacity to clean the air.  The additive is covered with tiny particles of titanium dioxide, which once applied to clothes, reacts with air and light to break down harmful emissions in the air.

This liquid additive, CatClo, can change ordinary clothes into catalytic converters, when added to the laundry powder and washed.  The  microscopic, pollution-eating particles in the additive will attach very firmly to the fabric so that only a single wash in the additive is required.  The air pollution particles will wash away when the clothes are washed again.

Helen Storey believes her “Catalytic clothing“, as she calls the clothes which are washed in the detergent, could contribute to a significant improvement in air quality.  The additive seems to work particularly well on denim and seeing that almost everybody has a pair of jeans in their closet, the pair think their product has a lot of potential. They hope they can persuade at least half the population to wear an item of catalytic clothing to help “suck up” and neutralize harmful emissions and therefore make the air around them cleaner.

Ryan and Storey say they won’t patent their invention, hoping all laundry manufacturers will add it to their products.  The additive could become commercially available within two years. Meanwhile safety tests are being done, but it seems that the additive poses no threat to human skin or water supplies.

Via: Reuters

Bacteria Form Undersea Power Cables

Danish scientists from Aarhus University have discovered bacteria in the seabed that function as living power cables. They exchange electrons with other bacteria, as far as 1 centimeter away. The findings were published in Nature on October 24.

The bacteria was first detected in 2010 by microbiologist Lars Peter Nielsen who was studying the mud upon the sea floor in the port of Aarhus. Nielsen discovered a seemingly inexplicable electric current in the undisturbed sea bed. Since then, Nielsen’s team has partnered up with the University of South California to find an explanation as to how and why this is happening. At the time they speculated that the electric currents might run between different bacteria via a joint external wiring network. After studying the sediment they discovered that there are tens of thousands of kilometres of the bacteria underneath the sea floor.

It was Nielsen’s student Christian Pfeffer, that recently found that the electric mud abounds with a new type of bacteria which align themselves into living electrical cables.  Each one of these ‘cable bacteria’, is a hundred times thinner than a human hair and contains a bundle of insulated wires that conduct an electric current from one end to the other. The bacteria belong to a microbial family called Desulfobulbaceae. The cable bacteria stretch out from the deeper mud where there is no oxygen, towards the surface which  has plenty of oxygen. Because the bacteria are joined into one long filament, the cells at the bottom can feed themselves with sulphur from the mud on the sea bed while getting oxygen from above.

The scientists are now investigating how the cable bacteria function at the molecular level. According to them, the discovery of these unique bacteria could also lead to a better understanding of the development of life on Earth.

Via: blogs.smithsonianmag.com/science/2012/10/live-wires-newly-discovered-seafloor-bacteria-conduct-electricity/

Scientists Create First All-Carbon Solar Cell

Scientists at Stanford University have developed a thin film solar cellprototype made entirely of carbon, making it a promising alternative to the increasingly expensive materials used in traditional solar cells.

Carbon has the potential to deliver high performance at a low cost and is Earth-abundant, according to the Stanford researchers. Conventional solar cells are primarily made out of ridged silicon and use rare metals for conductors, where as the Stanford cells are entirely made with flexible and inexpensive carbon materials. The carbon materials can be coated from solution. Others have previously claimed to have developed all-carbon solar cells,  but in those cases the use of carbon was limited to the middle active layer say the scientists.

Like a conventional solar cell, the Stanford prototype employs a photo-active layer that collects sunlight. That layer is sandwiched between two electrodes, and the flow of electrons from the photo-active layer to the electrodes creates the electrical current.

Carbon nanotubes have significantly better electrical conductivity and light absorption properties and would allow for easier production than conventional cells.  One drawback of the all-carbon prototype is that it still has an efficiency of less than 1 percent – much lower than commercially available solar cells.  The researchers are currently experimenting with a wide variety of carbon nanomaterials, looking to inprove the efficiency.

Even though the efficiency is still not up to scratch, the new solar solar cells have a significant advantage; they operate well under extreme conditions. Carbon is a very  resilient material that can remain stable at high temperatures where other cells would stop working.

The results were published on Wednesday in the online edition of the journal ACS Nano.

Via: news.stanford.edu/news/2012/october/carbon-solar-cell-103112.html