Assembling of MXenes from Liquid to Solid, Including Liquid Crystals, Fibers

Assembly of MXenes from the liquid phase into solid macrostructures brings important opportunities to construct functionalized MXene materials with the desired structure for applications in diverse fields. Due to their intrinsic flexibility and hydrophilicity, MXenes can be directly assembled from MXene colloidal solution by diverse solution-processed assembly techniques, which provides a simple and effective way to produce MXene-based macroscopic architectures, mainly including three kinds of dimensionality varied materials, named 1D fibers, 2D films, and 3D hydrogel or aerogels. This chapter starts with a brief overview of these MXene-based macroscopic assemblies, then these macroforms are introduced by dividing them into pure and composite assemblies with emphasis on their structural features as well as assembly strategies and mechanisms; the potential applications are also discussed, including conductive transparent coatings, electrochemical energy storage, drug delivery, sensing, and electromagnetic interference shielding. Finally, we offer insights into the prospects and the challenges ahead for rational design and controlled preparation of macroscopic MXene-based functional materials from solution.