Tuning of ionic transport through graphene oxide fibers by sheets size

In this study, graphene oxide fibers are introduced as new graphene oxide (GO) membranes with the ‎capability of ion selectivity‏.‏‎ Graphene oxide fibers, like other macro structured membranes, are always ‎associated with cavities and defects. To solve this problem, a 50% combination of graphene oxide ‎suspension including small sheets with an average size of ~ 0.5 µm2 and large sheets with an area of more ‎than 10 µm2 was used. According to the morphological results of scanning electron microscopy, as well as ‎the amount of ionic transport through the fiber, reduction of cavities and its defects were confirmed. ‎Moreover, it was found that ionic current through fibers consist of large and small GO sheets is more ‎controllable. This leads to more ionic selectivity via tunable swelling. Finally, the scalability of graphene ‎oxide fibers investigated and found that increasing number and length of the fibers increases the ionic ‎current as linear trend‎.