Hyperbranched polyethyleneimine for high-effective oil-water separation

Abstract

A series of hyperbranched polyethyleneimine (h-PEI) functioned with terminal amine groups is synthesized to remove oil from O/W emulsion. The demulsifier dehydration rate of h-PEI is systematically evaluated with the subsidiary facilities of DLS analysis, digital tensiometer and UV–vis spectrophotometer. The results indicate that h-PEI demulsifier displays satisfactory demulsification (the oil removal rate＞90%) with small dosage (＜80 mg L−1) and short settling time (＜30 min). The relatively short equilibrium time and great demulsification are ascribed to the amine groups and the molecular weight. On one hand, the hyperbranched macromolecules with amine groups can rapidly diffuse and adsorb to the oil-water interface, on the other hand, the molecules with adequate molecular weight are apt to flocculate, coalesce oil droplets, and then obtain high-efficient demulsification. The exceptional demulsification performance of h-PEI exhibits a potential role application in industrial water treatment or the petroleum demulsification industry.