Genoa, Italy – Up to 30g of oil could be removed from infected waters per gram of PU, according to a study into an alternative to traditional boom and suck methods used when spills affect the ocean environment.
Scientists at the Istituto Italiano di Technologia (IIT) published a paper on 2 March 2016 in the Journal of Physics which shows how foam can sponge the oil directly out of the water.
"We wanted to understand what the key features of such foams are, and how they can affect their performance" said Javier Pinto, the paper’s author.
"Particularly whether it was necessary to modify the surface chemistry, or if you could reach really good performance by simply choosing foams with the right structural parameters."
The experimental and theoretical study shows that with highly interconnected open porous structures, and pore sizes below 500 micrometres, it is possible to reach absorption capacities as high as 30g of oil per gram of polyurethane.
Chemical functionalisation of the porous structure did not appear to enhance the oil absorption efficiency, but did significantly contribute to the selectivity of the process.
"It came as a surprise that there is an absence of considerations of the structure or even characterisation of the foams employed in several previous studies" Pinto said.
"Understanding this is key to evaluating proposed treatments and coatings, and their effectiveness."
Pinto believes that due to the simplicity of the polyurethane foam they propose, commercialisation of the materials for oil spill remediation could happen very soon.
"Our next steps are to develop composite materials for wider water remediation" Pinto added. "These could be low environmental impact - using materials derived from waste - and have biodegradable or biocompatible properties."
"We'll explore the use of these systems not only for clearing oil spills, but also other contaminants such as heavy metals or pesticides."
Quingdao Science and Technology University researchers first suggested a PU foam solution for oil spills in 2014, as UTECH-polyurethane.com reported at the time.