In this paper, we report the formation
and transformation of graphene
oxide (GO) liquid crystalline (LC) structures in the synthesis and
deformation of tough GO nanocomposite hydrogels. GO aqueous dispersions
form a nematic LC phase, while the addition of poly(<i>N</i>-vinylpyrrolidone) (PVP) and acrylamide (AAm), which are capable
of forming hydrogen bonding with GO nanosheets, shifts the isotropic/nematic
transition to a lower volume fraction of GO and enhances the formation
of nematic droplets. During the gelation process, a phase separation
of the polymers and GO nanosheets is accompanied by the directional
assembly of GO nanosheets, forming large LC tactoids with a radial
GO configuration. The shape of the large tactoids evolves from a sphere
to a toroid as the tactoids increase in size. Interestingly, during
cyclic uniaxial tensile deformation a reversible LC transition is
observed in the very tough hydrogels. The isolated birefringent domains
and the LC domains in the tactoids in the gels are highly oriented
under a high tensile strain