Ionization-modified beetle structure for enhanced demulsification and anti-clogging performances

Superwetting materials are considered to have great potential for oil–water separation in water purification, food processing, petrochemical production, etc. However, weak demulsification performance and clogging are the key challenges in most practical applications. Here, we successfully prepared a charged beetle structure copper foam (SPCS-CF) with a surface composed of superhydrophilic charged carbon nanotubes and superhydrophobic SiO2 bumps, which can apply electrostatic force and wetting driving force to obtain higher demulsification and anti-clogging performances than conventional superhydrophilic materials. These two forces can cause the charged surfactant and the oil to move towards the charged carbon nanotubes and superhydrophobic SiO2 surfaces, respectively, resulting in charge heterogeneity and severe deformation of droplets, thereby enhancing the demulsification performance of SPCS-CF. Therefore, SPCS-CF can separate various oil-in-water emulsions with high separation efficiency (over 99.2 %) and high permeation flux (27,734.0 L m-2h−1). Furthermore, superhydrophobic SiO2 prevents oil droplets from accumulating in pores and causing clogging by aggregating them on the skeleton. Therefore, this charged beetle structure provides a new perspective for developing advanced materials for demulsification and separation in the petroleum industry and water purification fields.