Researchers at the Indian Institute of Technology Guwahati have developed two distinct and special membranes that can separate oil and water, even under harsh conditions.
The membranes, which are super water repellent in the air, and super oil repellent in water, have been shown to separate complex mixtures of oil and water at practically relevant settings. Oil-water separation is also important in environmental applications like oil spill management.
The research was undertaken by Dr Uttam Manna, Assistant Professor, Department of Chemistry, IITG, along with his research team of Avijit Das, Dibyangana Parbat and Arpita Shome.
Their work was recently been published in ACS Sustainable Chemistry & Engineering. The team then developed a prototype of oil-water separation device using these membranes in such a way that the separated oil and water were simultaneously collected in different containers.
Speaking on the need to develop materials that can separate oil and water, Dr Uttam Manna said, “Oil-water separation is of current relevance because many industries, such as mining, textiles, food and petrochemicals, produce massive volumes of oily waste water, which must be treated before discharge.”
There have been many studies on materials and techniques that can separate oil and water. In recent times, scientists have taken cues from Nature for this purpose. The lotus leaf for example, is water repellent, so that it does not get soggy in its living space. Fish, on the other hand, has a body surface that repels oil in order to survive in polluted waters.
While these bio-inspired membranes are individually used to separate oil and water in the recent past, there is accumulation of water or oil on the membrane over time, which blocks further separation.