The graphene oxide powder (GOP) obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets. The reduction of drying temperature can effectively increase the re-dispersibility of GOP

but result in a decreased drying efficiency. Herein

we found that the re-dispersibility of GOP is strongly affected by its microstructure

which is determined by the feed concentration. With the increase of feed concentration

the GO nanosheet assembly varies from the disordered stacking to relatively oriented assembly

making the morphology of the GOP transform from ball-like (the most crumpled one) to flake-like (the least crumpled one)

and the 0.8 mg·ml

-1

is the threshold concentration for the morphology

structure

and re-dispersibility change. Once the feed concentration reaches 0.8 mg·ml

-1

the appearance of the nematic phase in droplet ensures the relatively oriented assembly of GO sheets to form the layered structure with a low crumpling degree

which greatly improves the polar parts surface tension of the solid GOP

making the GOP easier to form hydrogen bonding with water during the redispersion process

th

us stabilizing dispersion. This work provides useful information for understanding the relationships between the morphology

microstructure

and final re-dispersibility of GOPs.