A hyperbranched Poly(amido amine) demulsifier with trimethyl citrate as initial cores and its demulsification performance at ambient temperature

In this work, a simple "one-pot" method was used to prepare the dendrimer-based demulsifier (PTC) with trimethyl citrate as the central core. The target product was determined by 1H NMR, FT-IR and GPC. Then, the important influential factors for the demulsification such as the demulsifier concentration, standing time and the emulsions salinity were investigated. Standing for 120 min at room temperature, the transmittance of the separated water could reach 91.5 % by adding 50 mg/L of PTC demulsifier. It showed much lower demulsification temperature and higher demulsification efficiency than previously reported demulsifers. The coalescence process of oil droplets in emulsions can be clearly understood by microscopic images and droplets size distribution. Further, surface tensions, dynamic interfacial tensions and zeta potential provided corresponding clues to the possible demulsification mechanism. It can be concluded that the hyperbranched demulsifier has potential application for the treatment of wastewater, and the current work may be helpful to explore the demulsification mechanism.