Superhydrophobic coating from fluoroalkylsilane modified natural rubber encapsulated SiO2 composites for self-driven oil/water separation

A superhydrophobic/superoleophilic mesh was successfully prepared in a simple and environmentally friendly process by coating with fluoroalkylsilane-modified natural rubber-encapsulated silica latex (FAS-modified NR/SiO2). TEM images confirmed the formation of a core-shell morphology, in which the rubber core was fully covered by a silica shell. This improved the thermal stability of the composites. Coating with FAS-modified NR/SiO2 enhanced both the hydrophobicity and surface roughness of the mesh. The depth profile of the XPS spectra revealed the presence of fluoroalkylsilane on the superhydrophobic mesh and Ar gas ion etching confirmed migration of the fluoroalkylsilane, SiO2, and carbon to the mesh surface. SEM and AFM results quantified the surface roughness of the coated mesh. Meshes coated with FAS-modified NR/SiO2 exhibited superhydrophobic/superoleophilic properties. Surfaces coated with these encapsulated particles were successfully applied to oil/water separation. They exhibited a separation efficiency of up to 100% and were reusable across 30 cycles.