Graphene oxide (GO), which consists of two-dimensional (2D) sp² carbon hexagonal networks and oxygen-contained functional groups, has laid the foundation of mass production and applications of graphene materials. Made by chemical oxidation of graphite, GO is highly dispersible or even solubilized in water and polar organic solvents, which resolves the hard problem of graphene processing and opens a door to wet-processing of graphene. Despite its defects, GO is easy to functionalize, dope, punch holes, cut into pieces, conduct chemical reduction, form lyotropic liquid crystal, and assemble into macroscopic materials with tunable structures and properties as a living building block. GO sheet has been viewed as a single molecule, a particle, as well as a soft polymer material. An overview on GO as a 2D macromolecule is essential for studying its intrinsic properties and guiding the development of relevant subjects. This review mainly focuses on recent advances of GO sheets, from single macromolecular behavior to macro-assembled graphene material properties. The first part of this review offers a brief introduction to the synthesis of GO molecules. Then the chemical structure and physical properties of GO are presented, as well as its polarity in solvent and rheology behavior. Several key parameters governing the ultimate stability of GO colloidal behavior, including size, pH and the presence of cation in aqueous dispersions, are highlighted. Furthermore, the discovery of GO liquid crystal and functionalization of GO molecules have built solid new foundations of preparing highly ordered, architecture-tunable, macro-assembled graphene materials, including 1D graphene fibers, 2D graphene films, and 3D graphene architectures. The GO-based composites are also viewed and the interactions between these target materials and GO are carefully discussed. Finally, an outlook is provided in this field, where GO is regarded as macromolecules, pointing out the challenges and opportunities that exist in the field. We hope that this review will be beneficial to the understanding of GO in terms of chemical structure, molecular properties, macro-assembly and potential applications, and encourage further development to extend its investigations from basic research to practical applications.

氧化石墨烯（GO），由二维（2D）sp ^2组成碳六方网络和含氧官能团，为石墨烯材料的大规模生产和应用奠定了基础。GO通过石墨的化学氧化制成，在水中和极性有机溶剂中具有高度分散性，甚至可以溶解，从而解决了石墨烯加工的难题，为石墨烯的湿法加工打开了一扇大门。尽管有缺陷，但GO仍易于功能化，掺杂，打孔，切成小块，进行化学还原，形成溶致液晶，并组装成具有可调结构和特性的宏观材料，可以作为活动的构建基块。GO薄板被视为单个分子，颗粒以及柔软的聚合物材料。对GO作为2D高分子的概述对于研究其固有性质和指导相关学科的发展至关重要。这篇综述主要关注GO片材的最新进展，从单分子行为到大分子组装石墨烯材料性能。本文的第一部分简要介绍了GO分子的合成。然后介绍了GO的化学结构和物理性质，以及其在溶剂和流变行为中的极性。重点介绍了控制GO胶体行为最终稳定性的几个关键参数，包括大小，pH值和水分散液中阳离子的存在。此外，GO液晶的发现和GO分子的功能化为制备高度有序，架构可调，宏观组装的石墨烯材料，包括1D石墨烯纤维，2D石墨烯薄膜和3D石墨烯结构。还查看了基于GO的复合材料，并仔细讨论了这些目标材料与GO之间的相互作用。最后，提供了该领域的前景，其中GO被视为大分子，指出了该领域存在的挑战和机遇。我们希望这篇综述对从化学结构，分子特性，宏观组装和潜在应用方面的理解起有益的作用，并鼓励进一步发展以将其研究从基础研究扩展到实际应用。还查看了基于GO的复合材料，并仔细讨论了这些目标材料与GO之间的相互作用。最后，提供了该领域的前景，其中GO被视为大分子，指出了该领域存在的挑战和机遇。我们希望这篇综述对从化学结构，分子特性，宏观组装和潜在应用方面的理解起有益的作用，并鼓励进一步发展以将其研究从基础研究扩展到实际应用。还查看了基于GO的复合材料，并仔细讨论了这些目标材料与GO之间的相互作用。最后，提供了该领域的前景，其中GO被视为大分子，指出了该领域存在的挑战和机遇。我们希望这篇综述对从化学结构，分子特性，宏观组装和潜在应用方面的理解起有益的作用，并鼓励进一步发展以将其研究从基础研究扩展到实际应用。