One-Pot Preparation of Macroporous Organic-Silica Monolith for the Organics-/Oil-Water Separation

Three-dimensional porous monoliths have been considered as attractive candidates for the organics-/oil-water separation due to their high porosity, low density and hydrophobic/oleophilic property. To simplify the preparation process, one-pot method based on thiol-methacrylate click polymerization was developed to fabricate macroporous organic-silica monolith by using octakis(3-mercaptopropyl)octasilsesquioxane, ethylene glycol dimethacrylate and heptadecafluorodecyl methacrylate as starting monomers. The rapid click polymerization was carried out at room temperature under air atmosphere, which made it possible for preparation of monolith with desired scale and geometry. The hybrid monolith with good thermal stability and compressibility generated through-pores with diameter ranging from several microns to tens of microns. As a result of the flexible organic linkages and fluorocarbon groups, the hybrid monolith showed hydrophobic feature, and could be fast swollen in organic liquids. Particularly, a cylindrical hybrid monolith (15 mm in diameter x 11 mm in height) supported by a modified syringe, which exhibited excellent recyclability and swelling-squeezing performance, has been applied to selectively absorb organic liquids located on the upper or under water layer.