Nanotech turns sawdust into carbon tubes

Posted Oct 30, 2014 by Tim Sandle
Scientists have developed a new method to make nanostructured carbon using the waste product sawdust. The tubes can be used as conductors, for a range of technological applications.
As interest in Earth s changing climate heats up  a tiny dark particle is stepping into the limeligh...
As interest in Earth's changing climate heats up, a tiny dark particle is stepping into the limelight: black carbon. Commonly known as soot, black carbon enters the air when fossil fuels and biofuels, such as coal, wood, and diesel are burned. Black carbon is found worldwide, but its presence and impact are particularly strong in Asia.
The process works by baking sawdust with a thin coating of iron at a super-hot 700 degrees centigrade. This heating process, dubbed “catalytic graphitization”, can create a form of carbon with a structure made up of many tiny “nano” tubes. The advantage of this method of manufacture is that is uses a waste product and that it is relatively cheap to operate. The waste product, from agriculture, would ordinarily be disposed of through landfill.
Carbon is formed because sawdust is made up of fibers of cellulose and lignin, two of the main building blocks of all plants. The heating process of the plant based biomass allows the sawdust to interact with iron nitrate, which produces carbide particles.
Carbon nano tubes are similar in shape and properties to graphene, rolled into tubes. The special shape of the materials provides them with particular properties, such as conducting electricity. The material is also very strong.
Carbon nano materials are in demand. Such products can be used for water treatment for removing pollutants (where the tiny pores act as ultra-fine filters). Another application is with soil remediation. Here nano carbon structures can aid the retention of moisture and nutrients in the earth. A more sophisticated application is with batteries and hydrogen-powered cars.
The research was led by Dr. Zoe Schnepp and it was conducted at the University of Birmingham in the U.K. The findings have been published in the journal Green Chemistry. The research is headed “Iron-catalyzed graphitization of biomass”.