Engineering network entanglement of functionalized graphene oxide/poly(acrylamide) nanocomposites for enhanced oil recovery

Abstract

Hydroxyl-functionalized graphene oxide (OGO) was prepared from graphene oxide (GO) modified by diethanolamine (DEOA) to promote the interaction between nano sheets and polymer molecules. Three OGO samples with different GO to DEOA ratios, and an acrylamide-based polymer (PM) were synthesized. The nanoparticle and polymer hybrid systems were prepared using GO or OGO suspension into PM solution. The interaction strength investigation indicated that the hybrid system had two kinds of hydrogen bonds, one is between amide groups on polymer and the other is between amide groups on polymer and hydroxyl groups on nanosheets, and there was a competition for them. As a result, a proper surface hydroxyl density is critical to form a suitable molecular network for improving the hybrid property under harsh condition. The rheological properties of PM solution and these hybrid systems were studied, and the results showed that the introduction of OGO obviously improved the salt-resistance and temperature-tolerance of PM solution. The results from oil displacement experiments showed that the enhanced oil recovery ratio jumped to 20.9% for PM/OGO system, while it was only 13.8% for PM solution.