π-π Stacking origin of irreversible dispersibility of graphene oxide.

Graphene oxide (GO) has become an increasingly important industrial chemical and useful two-dimensional material. The complexity in both functional groups and heterostructure of GO offers its rich chemistry yet complicates its stability, dispersibility and processing property. Interactions with functional groups have been pioneered to explain these confusing properties of GO. However, the critical role of structural heterogeneity keeps elusive. Here, we report that the irreversible dispersibility of GO solid origins from the interlayer π-π stacking and the accessibility between conjugated domains. Experiments and simulations reveal that the exclusion of interlayer water leads to irreversible π-π stacking. This insight into the π-π stacking mechanism informs the design of selective gelation paths, enabling the scalable, continuous production of highly conductive graphene-based hydrogel for neural probes. Our work unveils a general mechanism for confusing dispersibility of GO and opens supramolecular interactions modulating methods for assembled structures and materials.