Supergravity and In‐Situ Evaporation Induced Well‐Aligned and Self‐Crosslinked 2D Material‐Based Thin Films
Dawei Zhang, Abdallah Kamal, Baosong Li, Dezhuang Ji, Liming Zhao, Kang Cheng, Xuan Li, Sharmarke Mohamed, Qingwen Li, Liao Kin, Lianxi Zheng
Abstract
Abstract Assembling two‐dimensional (2D) nanoflakes into freestanding ultrathin films while maintaining their superior mechanical and functional properties can enable a wide range of applications. In this work, a versatile method is presented, based on supergravity drop casting combined with in‐situ evaporation to fabricate 2D thin films with excellent alignment, self‐crosslinking capability, and high compactness. Using this approach, free‐standing graphene oxide (GO) films with a thickness as low as 250 nm, an orientation factor of 0.92, and a record‐high tensile strength of 540 MPa are achieved. The supergravity field confines the 2D flakes within an ultrathin liquid layer and generates strong all‐directional shear forces that induce superalignment. Simultaneously, in‐situ evaporation accelerates dehydration and promotes ester bond formation between adjacent flakes, enabling self‐directed crosslinking. This method is further demonstrated to be applicable for creating patterned films and assembling other 2D materials such as MXene, graphene, and their heterostructures. The process, therefore, provides a universal and scalable platform for constructing high‐performance 2D building blocks for flexible electronics, membranes, and heterostructured devices.