Chemists of Tomsk Polytechnic University have developed a new material, which efficiently purifies water from petrochemicals. The material is based on polymer biomedical waste: surgical masks and hospital bedsheets. The material developed by the scientists possesses hydrophobic and oleophilic properties, as well as high oil adsorption capacity and low material cost. The research findings are published in the Journal of Environmental Chemical (IF: 5,909; Q1).
According to the scientists, the fibrous structure of surgical masks and disposable bedsheets opens up opportunities for their recycling for oil spill clean-up. Nevertheless, pristine polypropylene (PP) does not provide high adsorption capacity and functionality for selective entrapping of oils. Therefore, a relevant task was the development of new methods to improve PP properties for water purification from contaminants. The TPU team under Pavel Postnikov’s supervision, Associate Professor of the TPU Research School of Chemistry and Applied Biomedical Sciences, found such a method: they deposited a metal-organic framework on PP using a simple chemical method. As a result, the new material of superhydrophobic oleophilic fabric was synthesized.
“Metal-organic frameworks (MOFs) are porous organic compounds consisting of organic ligands and metal ions. We used zinc and imidazole derivatives as a ligand. Due to the well-ordered structure, frameworks are nanoporous and possess large specific surface area, i.e. they can absorb a very large amount of substance: oils and oil spills.
Crucially, we used fluorine-free ligands while hydrophobic properties were given due to the architecture of the MOF. Despite the fact that fluorinated ligands are superhydrophobic, the preparation and development of frameworks based on such ligands are quite expensive and time-consuming. Moreover, these ligands are not very good in terms of further recycling and exhibit toxic properties since released into water,” says Olga Guselnikova, a research fellow of the TPU Research School of Chemistry and Applied Biomedical Sciences, one of the authors of the article.
The research was conducted using a wide range of oils, including model samples. In the conducted experiments, the scientists simulated an oil spill: they mixed diesel, dyes, rust and other solid pollutants. The superhydrophobic oleophilic fabric proved to be rather efficient in removing contaminants. In addition, the experiments showed that it is mechanically strong and resistant to ultraviolet radiation.
“In the course of fundamental research, we obtained a prototype of the oleophilic fabric up to 65 square centimeters in size. Such a sample is a prototype for a potential application of the material: the fabric is spread on top of an oil spill and a minute later it is removed mechanically, taking all oil pollution with it and leaving clean water,” explains Pavel Postnikov.
Within the common Kolmogorov Russian-French project, the research team jointly with their French colleagues from Lille University of Science and Technology (France) are starting to research the functional processing of polymer waste to create sorbents and materials for the energy industry.