Recovering marine oil spills may soon become simple, efficient and cost-effective, thanks to a compound (gelator) developed by researchers at the Indian Institute of Science Education and Research (IISER) Thiruvananthapuram.
A team led by Dr. Kana M. Sureshan from the School of Chemistry used glucose as a starting material and through several chemical reactions produced compounds (gelators) that selectively congeal oil, including crude oil, from an oil-water mixture.
Unlike other alternatives, the gelators, which are in a powder form, can be easily applied over oil-water mixture and do not cause any environmental damage.
The results based on laboratory studies were published recently in the journal Angewandte Chemie .
“Unlike current methods, our gelator can recover oil from oil-water mixture and the gelator can be reused several times,” says Dr. Sureshan. “But in the case of crude oil, the gelator can’t be recycled. So our aim is to make the gelator cheaper and more efficient.”
The gelator molecule is partly hydrophobic and partly hydrophilic. While the hydrophilic part helps in self-assembling to form gelator fibres, the hydrophobic part is responsible for its diffusion into the oil layer.
“To achieve better diffusion of the molecule into the oil phase and enhance the oil recovery we increased the hydrophobicity. This was done by adding an aromatic/alkyl group at some part of the molecule,” he says.
Since the outer part of the fibre is hydrophobic, oil tends to gets into the spongy network made of fibres.
Once inside the fibre network, oil loses fluidity and becomes a gel. As the self-assembly is strong, the gel maintains its structure and rigidity even under pressure.
Strong gelWhen the researchers applied the compound on a benzene-water mixture and diesel-water mixture, it was able to congeal all the benzene and diesel within a short span of time. “The gel was strong enough to be scooped with a spatula,” says Dr. Sureshan. In the case of crude oil, it took a longer time for the compound to form a gel that was strong enough to be scooped off. “The crude oil is a mixture of several low- and high-boiling and polar and non-polar fractions. So the efficiency to form a gel is less in the case of crude oil,” he explains.
“We are trying to improve the efficiency of the compound in terms of better absorption capacity and use in real marine oil-spill situations. We will be testing the compound’s ability to form oil gels applied on ocean surface by artificially creating a marine oil-spill,” Dr. Sureshan says.
