Fabrication of raspberry-like starch-based polymer microspheres for W/O and O/W emulsions separation and purification

Oil/water separation and purification is an important pursuit because of uncontrolled emissions of industrial effluent , which has a catastrophic impact on our aquatic environment and body health. Here, an amino-functionalized composite particles material was developed via Pickering polymerization and grafting of poly(ethylene imine) (PEI). The wettability of the resultant composite particles can be easily regulated via changing the dosage of PEI. At lower dosage of PEI, the composite particles exhibited underoil superhydrophobicity (UOWCA: 158.8°) which applied to separate W/O emulsions with high flux (∼ 170 L/m 2 h). At higher dosage of PEI, it converted to underwater superoleophobicity (UWOCA: 158.1°) and could efficiently realize the separation of O/W emulsions with high flux (∼ 160 L/m 2 h bar). And at specific dosage range of PEI, the resultant composite particles can separate W/O and O/W emulsions simultaneously under the joint action of rough structures, unique surface wettability and positive charge. In addition, the resultant amino-functionalized composite particles were positive charged which could effectively absorb many anionic water-soluble pollutants with high removal rate of almost 90 % during oil/water separation process. This research may provide a new idea for intelligent oil/water separation and purification in the future.