Liquid crystals of graphene oxide: a route towards solution-based processing and applications

The liquid crystalline behavior of graphene oxide (GO) has enabled the design of facile and effective solution processing methods for assembling highly ordered macroscopic graphene structures, further expanding the development of novel graphene-based devices. In this progress report, first the preparation of liquid crystalline graphene oxide (LCGO) with a particular emphasis on different approaches to improve the oxidation efficiency and to control the GO sheet size is discussed. Then the use of LCGO dispersions in the solution processing of 1D, 2D and 3D architectures with highly tailored microstructures is covered. The LCGO composites are also reviewed as an important part of novel graphene-based multi-functional materials. Finally, various applications of LCGO are discussed to highlight the critical role of LCGO in expanding the applications of graphene. Based on these systematic discussions, an outlook on the future directions, challenges, and opportunities in this field is provided.