Constructing efficient and recyclable composite absorbent based on the modification of polymer skeleton with in situ assembled mesoporous silica/graphene oxide nanohybrid

Abstract

Polymers functionalized with hybrid nanoparticles are very popular for the preparation of composite absorbents with large surface area and good absorption capacity. However, the weak physical interactions between different nanoparticles allow for the easy destruction of the hybrid structure, which will greatly reduce the advantages of the hybrid nanoparticles as building blocks for the composite absorbent and decrease the stability of the composite absorbent in practical use. Here, in situ chemically boned mesoporous SiO2 (mSiO2)/graphene oxide (GO) nanohybrid (GO-mSiO2) was first synthesized by hydrolysis and condensation of tetraethylorthosilicate on the GO sheets, on which mSiO2 with the diameter of ca. 5 nm was uniformly distributed. Subsequently, a ternary absorbent with large surface area and very good water repellency was constructed by first impregnating commercial poly(melamine-formaldehyde) (MF) foam into GO-mSiO2 and then into polydimethylsiloxane (as cement and low surface energy source) solution. Because of the dually roughened skeleton surface with hybrid nanoparticles and the channel structure of mSiO2, the GO-mSiO2 modified hydrophobic MF (m-MF) foam possessed large surface area and high selective absorption ability for different oils and organic solvents from water, showing an absorption capacity that was up to 172 times its own weight. Moreover, m-MF can be recycled via the continued extrusion/sorption method. Taken together, these results suggest that the thus-prepared ternary absorbent can be applied as a potential candidate for the cleanup of oil spillage and toxic chemical leakage.