Enhanced oil-spill removal and recovery from water bodies using diatomaceous earth and C18-silane-grafted polyurethane

Abstract

This research focuses on the novel synthesis of polyurethane (PU) foam surface functionalized with diatomaceous earth (DE) particles and non-fluoro octadecylsilane (C18), for the use in enhanced clean-up of oil spill contaminants from water. The modified PU foam has improved hydrophobicity, wettability, water repellency, and biodegradability, which eliminates some of the drawbacks of PU such as its hygroscopic nature, limited hydrophobicity, ecotoxicity, and less biodegradability. The modified PU foam has been characterized by scanning electron microscopy to understand the microstructural changes during the surface modifications, Fourier transform infrared spectroscopy to track the integration of functional groups, X-ray crystallographic study to indicate the increase in the crystallinity of the resultant foam due to the incorporation of silane, and thermogravimetric analysis to understand the thermal stability and to calculate the thermal mass loss during the chemical modification. Furthermore, to test the enhanced hydrophobicity and oil spill clearance from water, the water contact angle has been measured and crude oil absorption capacity has been tested. The results show increased water repellency attributed to the strong hydrophobicity, and about 2.13 folds of increased crude oil absorption in comparison to the unmodified PU foam. Hence, the results collectively suggest the use of the synthesized surface-modified PU foam with superior hydrophobicity, water repellence, and surface wettability as a potential candidate for enhanced crude oil absorption from water bodies. Graphical abstract