Four novel environmentally friendly and highly branched crude oil demulsifiers were prepared by using different molecular weight (Mn = 350, 750, 1000, 1900 g/mol) of methoxy poly(ethylene glycol) to modify quaternized N,O‐carboxymethyl chitosan. Fourier transform infrared and 1H‐nuclear magnetic resonance were employed to confirm the structure of the demulsifiers. The surface tension of demulsifies was determined and hydrophile–lipophile balance value was calculated at the critical micelle concentration. The demulsification performance was evaluated by the bottle test method against water‐in‐oil emulsions simulated in the laboratory and it was found that the dehydration rate of four demulsifiers can come to 74.2%–80.4%, which have better demulsification performance than the commercial demulsifier JL‐1. Demulsification mechanism was discussed, and it was encouraging to find that the tiny water droplets in the emulsion coalesced to form the water phase and separated with the water from the polarization microscope. Results show that methoxy poly(ethylene glycol) grafted quaternized carboxymethyl chitosan has a promising application as a demulsifiers for dealing with W/O crude oil emulsions. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45867.

The removal of Fe3+, Cu2+,Cd2+,Cr3+and Zn2+ions from aqueous solution was studied by sorption onto polystyrene microcapsules containing 8-hydroxy-quinoline as extraction reagent. The micro-capsules containing 8-hydroxy-quinoline were prepared by solvent evaporation method with O/W emulsion and characterized by using optical microscope, Fourier Transform Infrared Spectroscopy (FT-IR). The uptake to Fe3+, Cu2+,Cd2+,Cr3+and Zn2+ions into the microcapsules was studied at deferent conditions. It showed that with the increasing dosage of microcapsules, the removal of metal ions increased too. The longer is standing time, the more is the increasing of adsorption capacity. The sorption of metal ions decreases with the initial pH of the solution increasing, and the sorption of microcapsule for metal ions is lower at 50°C. The sorption of Cr3+, Cu2+and Zn2+ions is highest at 45°C, and that of Fe3+, Cd2+is at 40°C. The results showed that the microcapsules could absorb Cr3+ions better than other metal ions.