Investigation of solution processable moisture barrier films based on a polymer and filler materials

Flexible printed electronics (FPE) attract significant interest due to their potential applications, ranging from printed circuits to wearable devices. Encapsulation of FPE devices is crucial to protect them from environmental factors such as moisture and oxygen. Solution-processed encapsulation by incorporating fillers into the polymer matrix is a promising method to produce barrier films on FPE devices. In this work, glass flakes, graphene oxide, montmorillonite, and silica are examined as potential fillers in poly(vinyl alcohol) (PVA). An adapted water vapor transmission rate (WVTR) dry cup method is developed to select the most effective filler. The optimal concentration of the selected fillers in PVA is determined. Moreover, the barrier effect of selected PVA/filler films is validated by resistance measurements of inkjet printed silver tracks subjected to damp heat and room storage conditions.