Nano foam sucks oil spills, pollutants, odour
doi:10.1038/nindia.2011.105 Published online 14 July 2011
Researchers have invented a new reusable nanocomposite from polymer foam and gold nanoparticles. The nanocomposite could be useful in removing toxic organic pollutants, oil spills and odorous substances from contaminated water.
Water contaminated through industrial processes usually contains considerable amounts of organic hydrocarbons, such as benzene, toluene, ethylbenzene and xylene (BTEX). These organic substances aid bacterial growth and generate odour-producing natural water bodies.
Although materials such as carbon nanotubes, metal nanoparticles and porous nanostructures are capable of removing organic pollutants, these materials often do not exhibit high adsorption capacity, long retention or high catalytic activity, and are not reusable.
To find a cost-effective and versatile material capable of removing toxic pollutants, the researchers blended gold nanoparticles with polymer foam produced from polydimethylsiloxane (PDMS) to yield a nanocomposite foam known as AuPDMS-2.
AuPDMS-2 was found to successfully adsorb organic pollutants such as BTEX from contaminated solvents within a few minutes. The foam was also able to rapidly suck up diesel oil from a water surface. AuPDMS-2 demonstrated high selectivity for sulphur-containing molecules such as thioanisole. Heating the material in air removed the adsorbed thioanisole, making the foam reusable.
Garlic owes its smell to sulphur-containing molecules. On treatment with the nanocomposite foam, the researchers showed that a water solution of garlic became almost completely deodorized. This foam could be moulded into any shape during or after synthesis for fitting into water channels or water bodies for practical applications.