Magnetic Fe3O4/Graphene/Dispersant Hybrids as a Highly Efficient and Recyclable Sorbent for Crude Oil

The magnetic Fe3O4/Graphene/Dispersant hybrids for oil–water separation were fabricated by the in situ synthesis of magnetic Fe3O4 nanoparticles on graphene sheets in the presence of the home-made dispersant, poly(oxyethylene)-segmented imide (POEM). The property of absorbing crude oil was examined. With POEM, graphene was dispersed with high specific surface area for oil absorption of crude oil at the capacity of 6 g g-1 by the pristine carbon material and 220 g g-1 by the dispersed graphene. By embedding the magnetic iron-oxide nanoparticles, the CPC graphene-like/POEM/Fe3O4 at 1/1/8 weight ratio enabled to absorb crude oil and resulting physically aggregating and being maneuverable under the applied magnetic field. Further, the absorption capacities of the CPC graphene-like/POEM/Fe3O4 remained after 10 times of repetitive usages and recyclability. Powder type of graphene/POEM/Fe3O4 and film type of graphene/POEM/water- borne PU were also prepared to enhance the possibility for realistic absorbing application, because rather than solution type of graphene/POEM/Fe3O4, powder type and film type can contact crude oil directly without using external mechanical force. Powder type of CPC graphene-like/POEM/Fe3O4 had only 10~20 g g-1 crude oil capacity so that it was not enough for practical application. On the contrary, film type of graphene/POEM/wPU had up to 93 g g-1 crude oil capacity and was applicable for realistic absorbing crude oil on sea water.