The demulsification of oily wastewater by a hyperbranched polymer grafted SiO2

In this work, a PAMAM@SiO2 demulsifier was synthesized by the reaction of a hyperbranched poly (amido amine) (PAMAM) and KH570 modified SiO2. The structure, morphology and composition of PAMAM@SiO2 were characterized by FT-IR, SEM and EDS. The effect of the concentration of PAMAM@SiO2, salinity and temperature on the demulsification performance was systematically studied. The results showed that the transmittance of aqueous phase after demulsification could reach as high as 92.1% at optimal conditions, and corresponding oil removal rate was 99.53%. Interfacial activity, three-phase contact angle, self-assembly of interfacial film and dynamic interfacial tension were investigated to explore the demulsification mechanism. Also, the aggregation process of oil droplets in emulsion was observed with a microscope. It indicates that the PAMAM@SiO2 demulsifier has a potential application in the treatment process of oily wastewater.