Nanomaterial for waste water treatment

New material has been developed for waste water treatment, which is ideally suited for removal of organics and oil spills because of its high and fast swelling capacity with longer retentivity, as demonstrated for diesel oil on water. Using Au nanoparticle-polydimethylsiloxane (AuPDMS) nanocomposites in the form of a foam. With this nanocomposite, one is able to bring together the unique properties of Au nanoparticles and PDMS elastomer. The synthesis is a single step room temperature process involving reduction of Au3+ ions from KAuCl4 precursor in PDMS matrix in presence of water, thus eliminating the need of external reducing and capping agents. It is essentially a green process. The Au nanoparticle loading in the PDMS foam has been optimized (0.03 wt%) to attain a low density (~1.1 g/cm³), high compressiblity (~105%) as well as pore volume (~5.45 cm³/g), towards making it a high performance material. The performance of AuPDMS nanocomposite has been tested against BTEX for comparison, where the sorbent capacity is found to be nearly six times higher compared to PDMS foam without Au nanoparticles. (Ritu Gupta and Giridhar U. Kulkarni, Chemistry and Physics of Materials Unit and DST Unit on Nanoscience, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore.)