IIT Guwahati team claims developing industrial-use graphene nanosheets for separating oil and water

GUWAHATI: Researchers at the Indian Institute of Technology Guwahati claim they have developed graphene-based "superhydrophobic" material that can separate oil and water, thus having wide uses in industry and healthcare.

Superhydrophobic materials – materials with extreme water repellency – are considered the best for removing oil from water, but they are generally not scalable, use environmentally toxic products such as fluorinated polymers, or have poor mechanical and chemical stability.

IIT Guwahati researchers manipulated graphene, a form of carbon, to have superhydrophobic properties suitable for separation of oil from water in emulsions, said their research paper in the Chemical Science journal authored by Dr. Uttam Manna and research scholars Avijit Das, Kousik Maji, and Sarajit Naska.


The team developed a method to produce graphene oxide-polymer composite with "hierarchical topography and low surface energy chemistry in the confined space". They further deposited iron oxide nanoparticles on the two dimensional nanosheets, which made the entire material magnetically active.

“Our graphene oxide composites were able to separate oil from water in emulsions with high efficiency,” said Dr. Manna, adding that this was uniquely done under extremes of pH, salinity and surfactant contaminations as in real-life situations.

This graphene oxide species was capable of selectively soaking up tiny crude-oil droplets in oil-to-water emulsions with high absorption capacity (above 1000 wt%), as well as coalescing larger oil droplets of emulsions from water-in-oil emulsions, the institute claimed.

There is extensive global research on using "wonder material" graphene - a carbon allotrope similar to graphite, but much stronger and lighter - in applications that require superhydrophobicity, but attempts to engineer its composition have proved challenging.