Researchers at the Indian Institute of Technology (IIT) Guwahati created a unique, extremely porous and water repellent superhydrophobic cotton composite material comprising a Metal-Organic Framework (MOF) that can selectively absorb oil from an oil-water mixture. Regardless of the chemical composition or density of the oil, the substance has a separation efficiency of 95 to 98 percent.
The research was aimed at solving the problem of water pollution. The practical applications of the research include cleaning spilled oil from river, sea or ocean water. Both heavy and light oils can be effectively absorbed by the material. The material is easy to prepare, cost-effective and recyclable, the institute said. It has been published in the journal ACS Applied Materials and Interfaces of the American Chemical Society.
MOFs are a class of compounds containing metal ions coordinated to organic ligands to form 3D structures. They are often highly porous materials that act like a sponge, IIT Guwahati said. The team initially developed a superhydrophobic MOF which can repel water and float on the water surface. Then, they grew the same MOF on the surface of medical cotton.
They have grown the MOF on the surface of medical cotton, which is environmentally friendly and cost effective. The flexible superhydrophobic MOF composite showed an oil absorption capacity more than 2500 wt%. Motor oil, kerosene and gasoline were used to investigate the real-life potential of the material for oil-spill clean-up.