Binder-free Graphene/Silver Nanowire Gel-like Composite with Tunable Properties and Multifunctional Applications.

To realize macroscopically utilization of the excellent properties of graphene, various forms of graphene assemblies have been investigated. Among them, the gel form assemblies show great advantages because they are shapeable and self-healable, and their manufacturing processes are facile and simple. In the conventional gel formed graphene assemblies, a relatively large content of binders, including hydrophilic polymers, celluloses, or amorphous inorganic materials are mixed with the graphene to achieve the gelation. However, these binders are electrically nonconductive and electrochemically inactive. Thus, the favorable functionalities of the composite will be weakened, and the potential advantages of graphene cannot be fully utilized. Herein, a binder-free silver nanowire (Ag-NW)/reduced graphene oxide (rGO) gel-like composite is designed and successfully fabricated by using ultra-long Ag-NWs to enhance the hierarchical synergistic effects. The fabrication technique is highly efficient and repeatable, and the obtained composite is flexible, stretchable and self-healable. Furthermore, the overall properties of the composite can be easily adjusted in a wide range by controlling the mass ratio between Ag-NW and rGO, which makes it multipurpose and suitable in different applications. Several demonstrations have been carried out and some special performances including linear strain sensing range and rapid transformation from wet to dry state are found in this unique composite. This binder-free structure could also be expended to other material systems, which may offer a valuable inspire for the development of functional devices based on nanocomposite.