Frontiers in Chemistry (Dec 2020)

Alkyl Chain Grafted-Reduced Graphene Oxide Membrane for Effective Separation of Water/Alcohol Miscible Mixtures

  • Hailong Zhang,
  • Jianbo Yang,
  • Ting Li,
  • Xingxiang Ji,
  • Zhen Xu,
  • Yaling Zhu,
  • Libin Liu

DOI
https://doi.org/10.3389/fchem.2020.598562
Journal volume & issue
Vol. 8

Abstract

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Separation of water/alcohol miscible mixtures via direct filtration only under gravity is a great challenge. Here, different alkyl chain grafted-reduced graphene oxide (alkyl-RGO) is synthesized and characterized. The hydrophobic alkyl chains can considerably modify the oil-wettability of the membranes and avoid water permeation. The alkyl-RGO membrane obtained by vacuum filtration can separate water/oil immiscible mixtures. Importantly, water/alcohol miscible mixtures could also be separated solely under gravity, where alcohols efficiently permeate the alkyl-RGO membrane while water is prevented through the membrane. The separation efficiency of C12H-RGO membrane reaches up to about 0.04 vol% of water content for the case of separating an n-propanol/water (90:10 v/v) mixture with high n-propanol permeability of approx. 685 mL m−2 h−1. Molecular simulations indicate that the selective absorption ability and diffusion rate also affect water/alcohol separation. The alkyl-RGO membranes via gravity driven filtration can extend the applications of separation of water/alcohol miscible mixtures.

Keywords