Fabricating structural adhesive bonds with high electrical conductivity

Abstract

In this paper we present a new approach, called Two-Step-Functionalization approach to integrate electric conductivity function into structural adhesive bonds. A nylon textile is used for supporting polymer adhesive film and it is especially surface-coated with silver (Ag) to produce an electrically conductive adhesive film. This is the first-step-functionalization and it occurs at micro-scale. The functionalized film is then surface-loaded on the both sides with three-dimensional tetrapod-like zinc oxide (TZnOs) particles coated again with Ag to form a sandwich structure, where the both thin surface layers are TZnO-rich. The sandwich film is then positioned between two aluminum adherends and bonded at the curing condition. In the context, this is the second-step-functionalization, and this occurs at nano-scale. Obviously, both the functionalization provides not only significant mechanical reinforcing efficiency, but also electrical connection between the bonded joints. Eventual electrical isolation effect is avoided which often occurs if the interface between the adhesive film and metal adherend is wetted by the adhesive in a low viscosity window during the curing process. As demonstrated, the adhesive bonded joints using a very limited amount of Ag as coating material shows a unique high electrical conductivity and better mechanical properties as compared to baseline counterparts.