In this paper, we report graphene composite membranes prepared by transfer of a layer of chemical vapor deposition graphene onto porous anodic alumina (AA) substrates with nominal pore size 20 and 30 nm, referred as 20AA and 30AA. The coated and uncoated substrates were characterized using optical and electron microscopy techniques. The bare substrates exhibited a smooth surfaces with a well-organized array of hexagonal pores, displaying an average pore size of 17 ± 3 (20AA) and 23 ± 3 nm (30AA). The scanning electron microscopy and atomic force microscopy analyses confirmed the successful transfer of graphene layer onto the target substrates. The molecular transport study was performed by introducing 0.5 M potassium chloride (KCl) and deionized water in a Side-bi-Side Franz diffusion cell. The graphene/20AA specimen blocked 66% ions transport, and graphene/30AA membrane about 64%. The ions blockage exceeded 90%, near the characteristics of defectfree graphene when the defects of the transferred graphene were sealed with Nylon 6,6. The results of this study suggest the potential use of graphene on AA substrates for water desalination and gas purification applications.

    Abstract
    Graphic abstract
    1 Introduction
    2 Materials and methods
        2.1 Materials
        2.2 Production, transfer, and characterization of graphene
        2.3 Molecular transport experiments
        2.4 Interfacial polymerization (IP)
    3 Results and discussion
        3.1 Optical microscopy analysis of uncoated membranes
        3.2 SEM analysis of uncoated membranes
        3.3 AFM analysis of uncoated membranes
        3.4 TEM, AFM, and Raman spectroscopy analyses of graphene
        3.5 SEM and AFM analyses of graphene-coated membranes
        3.6 Molecular transport analysis of bare and coated substrates
    4 Conclusion
    Acknowledgements 
    References

• Sultan Akhtar(Department of Physics, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University)
• Sadaqat Ali(Mechanical and Energy Engineering Department, College of Engineering, Imam Abdulrahman Bin Faisal University)
• Feras M. Kafiah(Department of Mechanical Engineering, Al-Hussein Technical University)
• Ahmed Ibrahim(Department of Mechanical Design and Production Engineering, Zagazig University)
• Asif Matin(Center for Research Excellence in Desalination and Water Treatment, King Fahd University of Petroleum and Minerals)
• Tahar Laoui(Department of Mechanical and Nuclear Engineering, University of Sharjah)