Adhesion of silver nano wire graphene composite film.

Silver nanowire graphene (AgNW-GN) composite, as an alternative transparent conductive film (TCF) to conventional indium tin oxide (ITO), has much improved mechanical and electrical properties. These advantages make AgNW-GN an ideal TCF for planar devices. The adhesion of AgNW-GN composite film plays a critical role in these applications. However, the effect of silver nanowire on the adhesion between AgNW-GN and copper substrate remains unexplored. In the present work, AgNW-GN composite films with different AgNW concentrations were prepared and their adhesion with copper substrates was characterized using the double cantilever beam (DCB) experiment and the digital image correlation (DIC). The interfacial failures were characterized using scanning electron microscopy (SEM), Raman spectroscopy, and atomic force microscopy (AFM). The results showed the brittle to ductile interfacial fracture transition with increased amount of AgNW. The interfacial traction separation relations (TSR) were subsequently extracted. The competing interfacial failure mechanism was discovered and modeled between the interfaces of epoxy/composite and composite/copper. The associated transfer criterion was subsequently established combining both experimental and modeling results.