Graphene Oxide Liquid Crystals: Discovery, Evolution and Applications

Abstract

The discovery and relevant research progress in graphene oxide liquid crystals (GOLCs), the latest class of 2D nanomaterials exhibiting colloidal liquid crystallinity arising from the intrinsic disc-like shape anisotropy, is highlighted. GOLC has conferred a versatile platform for the development of novel properties and applications based on the facile controllability of molecular scale alignment. The first part of this review offers a brief introduction to LCs, including the theoretical background. Particular attention has been paid to the different types of LC phases that have been reported thus far, such as nematic, lamellar and chiral phases. Several key parameters governing the ultimate stability of GOLC behavior, including pH and ionic strength of aqueous dispersions are highlighted. In a relatively short span of time since its discovery, GOLCs have proved their remarkable potential in a broad spectrum of applications, including highly oriented wet-spun fibers, self-assembled nanocomposites, and architectures for energy storage devices. The second part of this review is devoted to an exclusive overview of the relevant applications. Finally, an outlook is provided into this newly emerging research field, where two well established scientific communities for carbon nanomaterials and liquid crystals are ideally merged.

Multifunctional non-woven fabrics of interfused graphene fibres

“…The non-woven configuration is convenient to reach an adequate packing density, thus facilitating the integral fabric performance, and is technically viable for industrial production of GFFs. Graphene fibres were prepared using a wet-spinning protocol1181920. To realize interfibre bonding, we initiate a wet-fusing assembly approach based on self-assembly of the as-prepared GO fibres.…”

Conductive Tough Hydrogel for Bioapplications

“…The conductivity of our optimal PUHC composite is compared to previous reports of conducting PU composites in Table 2 . The increase in conductivity may be due to the establishment of LC structure in PUHC (transfer isotropic to nematic structure) . Percolation threshold results comparing the electrical behavior of LCGO and PEDOT:PSS/LCGO composites suggested that lower amounts of filler are needed to create conducting paths in an isolating matrix of PU.…”

An asymmetric electrically conducting self-aligned graphene/polymer composite thin film for efficient electromagnetic interference shielding

“…At above a critical concentration, GO/polymer dispersion can form a self-aligned ordered structure as a result of configurational-entropy driven excluded volume interactions between the GO sheets and the high affinity between the polymer wrapped amphiphilic GO sheets. 34 Especially, the extremely high aspect ratio (∼ 15000) of GO sheets induced a highly anisotropic (aligned) composite film during self-assembly process. Further, it is noted that density of GO is ∼ 2.24 g/cm 3 , while PVDF-HFP possesses density of 1.78 g/cm 3 .…”