Synthesis of a Novel Environmentally Friendly andInterfacially Active CNTs/SiO 2 Demulsifier for W/O CrudeOil Emulsion Separation

Abstract

In the current study, novel environmentally friendly and interfacially active carbon nanotubes/SiO2 nanomaterials (CNTs/SiO2) for emulsified crude oil separation were prepared via grafting nano-SiO2 on the surface of oxidized carbon nanotubes (Ox-CNTs). The structure of the as-prepared CNTs/SiO2 was characterized by Fourier transform infrared spectroscopy, UV–visible absorption spectra, Raman spectra, X-ray diffraction spectra, thermogravimetric analysis, field-emission scanning electron microscope, and energy-dispersive X-ray spectroscopy. Besides, three-phase contact angles (θ) were employed to evaluate the wettability of CNTs/SiO2. Also, it was found that the θ value of CNTs/SiO2 was about 90°. The nanomaterials with interfacial activity can spontaneously assemble at the oil–water interface, thus improving the droplet coalescence in the emulsion. Afterward, the demulsification performance was evaluated in crude-oil emulsions using the bottle test, which demonstrated that the demulsification efficiency ...