Silica aerogel composite with inherent superparamagnetic property: a pragmatic and ecofriendly approach for oil spill clean-up under harsh conditions

Abstract

Mineral oil spills over aquatic bodies have very serious and adverse impacts on the environment and ecological wellbeing, in addition to causing enormous economic and social fallouts. Current technologies for remediation of oil spills are far from adequate in terms of cost, efficiency, ease of operation, and environmental safeguards. Towards obviating the current shortcomings, a silica aerogel-melamine-formaldehyde foam composite with inherent magnetic characteristics [magnetic foam aerogel composite (MFAC)] was developed through a cost-effective and scalable ambient pressure drying (APD) method. The composite is equipped with enhanced porosity, oleophilicity, and remarkable hydrophobicity (contact angle of 142°). The pore characteristics of the MFAC composite introduced by the silica aerogel network facilitate very swift oil sorption and good retention, which prevent oil spreading and minimize harm to the environment. MFAC is found to be very effective with both low- and high-viscosity oils as well as common organic solvents. A maximum sorption capacity for petroleum oil and chloroform was found to be 32 g/g and 42 g/g, respectively. The material displays satisfactory performance under various adverse environmental conditions (acidic, alkaline, saline, low/high temperature) with no signs of abatement in its performance. Easy maneuvering of the composite over a wide area on the waterfront and retrieval were accomplished by the application of an external magnetic field. The sorbed oil can be recovered through simple mechanical squeezing. MFAC has good structural integrity and sorption stability and can be used for several cycles without diminution in the oil absorption capability. MFAC is swift, scalable, reliable, and easily deployable, which is expected to address most of the practical difficulties encountered with the current oil spill remediation methods.