Published: 21st September 2021
IIT Guwahati develops water repellant material to absorb oil selectively from oil-water mixture
MOFs are a class of compounds containing metal ions coordinated to organic ligands to form 3D structures, with the special feature that they are often highly porous materials that act like a sponge
Researchers at Indian Institute of Technology (IIT), Guwahati have developed a novel highly porous and water repellent superhydrophobic cotton composite material which can help in treatment of industrial oily waste water and the separation of oil spill from water.
According to the team, in petroleum industry, oil leakage and oil spill accidents happen frequently during offshore oil exploitation and oil transportation. This severe water contamination threatens the health of human beings and other living species.
Therefore, the treatment of industrial oily wastewater and the separation of oil spill from water has become a worldwide challenging task. To overcome this problem, the IIT Guwahati researchers have synthesised a superhydrophobic Metal-Organic Framework (MOF) composite with cotton to absorb oil selectively from water.
The results of the research has been published in the reputed peer-reviewed journal "ACS Applied Materials and Interfaces" belonging to the American Chemical Society. "In our work, we focused on a real problem in environmental water pollution in current time. Our goal was to develop a new material which could be synthesized easily and should be cost effective. We have grown our new MOF material on the surface of medical cotton, which is environment friendly and cost effective. Such low-cost material will reduce the production cost of the material for large scale industrial synthesis for real applications, compared to currently available materials in the market," said Shyam P Biswas, Associate Professor, Department of Chemistry.
In a vast country like India where petroleum hydrocarbons are the major sources of fuel, accidental oil spills occur frequently during transportation and storage of oils, he said, adding the material developed in their laboratory will be beneficial to reduce the environmental water pollution by efficiently absorbing the spilled oil from environmental water.
Biswas explained the MOF composite has great capability for selective separation of the oils from oil and water mixtures, and the separation efficiency lies between 95 and 98 per cent, irrespective of the chemical composition and density of the oils. MOFs are a class of compounds containing metal ions coordinated to organic ligands to form 3D structures, with the special feature that they are often highly porous materials that act like a sponge.
Besides, the MOF composite is also able to absorb large volumes of oils and can be reused for minimum 10 times so that the sorbents can provide more recovery of the spilled oil. The team initially developed a superhydrophobic MOF which can repel the water and float on the water surface.
Then, they grew the same MOF on the surface of medical cotton. It was observed that the medial cotton changes from hydrophilic to superhydrophobic material and can float on the water surface. "The growing environmental pollution is a serious threat to our society for sustainable development. Among the various environmental problems, water pollution is one of the serious issues in India. Until now, petroleum hydrocarbon products are the main energy sources in the world," Biswas said.