Tuesday, 21 January 2014

New CNT sponge developed with better Water clean-up capabilities

A carbon nanotube sponge efficient enough to soaking up water contaminants, such as fertilisers, pesticides and pharmaceuticals, over three times more capably than previous efforts has now been presented.

CNTs are hollow cylindrical structures made up of a single sheet of carbon because of which, CNTs have astonishing thermal, chemical and mechanical properties that have found  CNTs numerous applications in different zones of science and technology. E.g. body armour , solar panels etc.

They were called for wastewater cleaning. However, it was difficult to use them if contaminants were fine powder. The carbon nanotube (CNT) sponges, uniquely doped with sulphur, demonstrated a high capacity to absorb oil, potentially opening up the possibility of its applications in industrial mishaps and oil spill clean-ups. According to Lead author of the research published in Journal Nanotechnology, Luca Camilli, from the University of Roma, it is tricky to use CNT powders to remove oil spills from the ocean as they are difficult to handle and tend to get lost or dispersed in ocean after their release. But millimetre- or centimetre-scale CNTs synthesised in this study, are much feasible to be used as they tend to  float on water because of their porous structure and, once saturated with oil, they can be easily removed. By mere squeezing them and releasing the oil, they can again be re-used. Hence, CNT sponge of average length of 20mm was synthesized by the team of researchers from University of Roma, University of Nantes and University of L'Aquila, by adding sulphur and ferrocene during production. Defects on surface of CNT sponges were caused due to addition of sulphur which enabled ferrocene to deposit iron into tiny capsules within carbon shells. Hence, now these sponges could be magnetically controlled without any direct contact.
It was demonstrated how the constructed CNT sponges could successfully remove a toxic organic solvents like dichlorobenzene from water. It could absorb a mass that was 3.5 times higher than what was previously achieved, also  vegetable oil up to 150 times of its initial weight and engine oil to a slightly higher capacity than previous reported.

Furthers, researchers have planned to study toxicity of sponges and their commercial scale production so that they can be used in real world applications.