Spinning a graphene rope

Graphene oxide nano-flakes have been spun into graphene fibres several metres long by researchers in China. This could be the key to using graphene in the real world, as it takes tiny flakes and creates a macroscale material that has graphene's great physical properties - strength and high thermal and electrical conductivity.

In work published in Nature Communications (2011, DOI: 10.1038/ncomms1583), Zhen Xu and Chao Gao at Zhejiang University in Hangzhou, used wet spinning to turn an aqueous solution of graphene oxide into long fibres, before reducing the fibres to pure carbon. The trick is to use such a concentrated solution of graphene oxide flakes that it becomes a liquid crystal, allowing it to flow but retain an ordered structure.

Although carbon nanotube fibres have been made before, and are stronger than these ropes at the moment, the manufacture of the graphene rope is much easier, especially as carbon nanotubes are so difficult to make.

 

Artificial enzymes close in on nature

A synthetic metalloprotein that approaches the catalytic performance of a natural enzyme, despite its stripped-down structure, has been published by a team of chemists in the US in Nature Chemistry (2011, DOI: 10.1038/nchem.1201). The computer-designed carbonic anhydrase mimic is the work of Vincent Pecoraro and his colleagues at the University of Michigan in Ann Arbor.

Pecoraro's artificial enzyme catalyses the conversion of carbon dioxide and water into bicarbonate, a biologically important process that may one day also play a role in sequestering carbon dioxide from the atmosphere. The mimic - which consists of a three-stranded 'coiled coil' protein binding a zinc-based active site - is only 500-fold less efficient at catalysing this reaction than the natural enzyme, a result 70-fold better than the previous best synthetic carbonic anhydrase. 

This performance comes despite the artificial enzyme lacking the outer 'second sphere' structure of natural enzymes that can stabilise transition states and assist proton transfer. 'We were pleasantly surprised by this level of catalytic activity,' Pecoraro says. 'The work shows that if a metal can be bound in a hydrophobic environment in aqueous solution, a significant activity can be achieved without designing second sphere effects.' 

 

Cancer diagnosis goes for gold

Gold nanoparticles could help diagnose a wide range of different cancers by detecting telomerase activity within cells, say Chinese chemists. 

Because telomerase is over-expressed in over 85 % of all tumours, it would make a good general biomarker for cancer. But although techniques exist for detecting telomerase levels, they suffer from some serious limitations, including being time-consuming, expensive, and not particularly accurate or sensitive. 

Publishing in Small  (2011, DOI: 10.1002/smll.201101938), the team coated gold nanoparticles in a synthetic telomere that could be extended by telomerase. Placing these gold nanoparticles in a salt solution caused them to bunch together, shifting their fluorescence from red to blue. If, however, the gold nanoparticles are first exposed to telomerase, then the extended telomere molecules prevented the nanoparticles from bunching up and they continued to shine red. 

 

Nasa turns to material dark side

Nasa scientists have embraced the dark side, creating the blackest material ever. It absorbs almost all light across multiple wavelengths and promises to open new frontiers in space technology.  

Special paints can absorb light in the UV to near infrared spectrum, but this new material, developed at Nasa's Goddard Space Flight Center in Greenbelt, Maryland, performs far better and is far less dense than current efforts. 

The material absorbs more than 99.5% of UV and visible light, dipping to 98% in longer or far-infrared bands. This makes it ideal for suppressing stray light, which can contaminate measurements of bright objects or overwhelm observations of dim objects far out in space. 

 

£125m fund for UK advanced manufacturing

The Department of Business, Innovation and Skills (BIS) in the UK has launched a new initiative to improve the global competitiveness of UK advanced manufacturing supply chains, announced Business Secretary Vincent Cable in December.

The new £125 million fund will support innovative projects in both established areas, including chemicals, as well as targeting newer areas such as renewable energy and other low carbon sectors.

Applications are invited for early 2012 and will be flexible in the support offered. 'British suppliers have a lot to offer and we need to help them realise and develop their strengths and sell them on the international market,' said the Business Secretary in a statement.

 

Bio-light

Philips has launched a design concept that uses bioluminescence to create an ambient light fitting.

The glass pods are home to cultures of bioluminescent bacteria that can be fed with methane from digested home waste as well as composted material from the home.

Each cell is connected via silicon tubes to the food source, which could come from the kitchen. And the system can be freestanding or hung on a wall using the steel frame.

Although the idea of sharing your home with so many bacteria might seem odd, the self contained system could help with recycling and environmental monitoring, say Philips. However, this is just a proof of concept at the moment. There is no date yet for the system to find its way into our homes.

 

EPA revises pollution standards

The US Environmental Protection Agency (EPA) is proposing changes to the Clean Air Act standards for industrial boilers and certain incinerators. The new standards would greatly reduce the emissions of mercury, soot, and other toxic air pollutants, but reduce compliance costs for industry. 

The proposal revises a set of regulations for boilers and solid waste incinerators that the EPA finalised in February under a court-ordered deadline. The EPA agreed to revisit those standards in response to criticism by manufacturers and many members of Congress that the agency's initial plan would have imposed a massive burden on the economy. 

Boilers are the second-largest source of toxic mercury emissions, after coal-fired power plants. 

 

Osmotic shocking route to nanopores?

Scientists in the UK have come up with a new method to create nanoporous materials. The method, which uses osmosis to drive a minor component from a material, should make nanoporous materials easier to manufacture for applications such as filtration. 

The researchers used polystyrene filled with tiny spheres of polymethyl methacrylate (PMMA). They then exposed the composite material to ultraviolet light, which broke the PMMA down into its constituent oligomers, forming small domains.  

In the next, crucial, step, the researchers wetted the material with acetic acid, which dissolves the PMMA. Although the acetic acid couldn't reach the PMMA oligomers directly, it could diffuse through the polystyrene via osmosis, gradually filling up the PMMA domains. Eventually, the domains grew so big from the absorbed acid that they broke through the walls - a process known as collective osmotic shock - leaving the polystyrene full of nanopores.  

The researchers have already tested their nanoporous polystyrene and have shown that it can function as both a water filter that can remove dye, and as a one-dimensional photonic crystal. 

The work is published in the journal Nature Materials (2011, DOI: 10.1038/nmat3179). 

 

South Korea ratifies trade deal with US

South Korean president Lee Myung-bak has signed the bills needed to implement South Korea's free trade agreement with the US. 

The signing ceremony was held in Seoul a week after the trade pact and 14 related bills passed through the Korean National Assembly and one month after the US Congress approved the agreement. 

The deal will phase out most tariffs and other trade barriers between the two nations and could have already taken affect by the time you read this. 

Korea is the seventh-largest export market for the American chemical industry. More than 82% of US chemical products shipped to Korea will receive duty-free treatment within three years after the agreement enters into force.