Fig. 6. (a) 1 μm-thick pure GO membrane; (b) the cross-section SEM image of pure laminated GO membrane; (c) 0.2 μm-thick r-GO membrane; (d) the cross-section SEM image of pure laminated r-GO membrane; (e) stability of pure GO laminates, r-GO composites membranes in neutral, acidic and alkaline solution. (a) and (b) Reproduced with permission from ref. 46. Copyright© 2012, American Association for the Advancement of Science. (c) and (d) Reproduced with permission from ref. 74. Copyright© 2014, John Wiley and Sons.