Use of amphiphilic triblock copolymers for enhancing removal efficiency of organic pollutant from contaminated media

Abstract

We have studied amphiphilic triblock copolymers poly(ethylene glycol)-b-poly(propylene glycol)-b-poly(ethylene glycol) (PEG-b-PPG-b-PEG) and poly(propylene glycol)-b-poly(ethylene glycol)-b-poly(propylene glycol) (PPG-b-PEG-b-PPG) as possible substitutes for sodium dodecyl sulfate as anionic surfactants for the removal of hydrophobic contaminants. The triblock copolymers were compared with sodium dodecyl sulfate in terms of their abilities to remove toluene as hydrophobic contaminant in fuel, and the effects of polymer structure, PEG content, and concentration were studied. The PEG-b-PPG-b-PEG copolymer containing two hydrophilic PEG blocks was more effective for the removal of hydrophobic contaminant at extremely high concentration. We also measured the removal capabilities of the triblock copolymers having various PEG contents and confirmed that removal capability was greatest at 10% PEG content regardless of polymer structure. As with sodium dodecyl sulfate, the removal efficiency of a copolymer has a positive correlation with its concentration. Finally, we proposed the amphiphilic triblock copolymer of PPG-b-PEG-b-PPG bearing 10% PEG content that proved to be the most effective substitute for sodium dodecyl sulfate.