High-resilience conductive PVA+AgNW/PDMS nanocomposite via directional freeze-drying

In this study, a polymer/metal nanowire nanocomposite employing a hard-core-soft-matrix design is developed, demonstrating high strength, recoverability, and electrical conductivity. Incorporation of conductive fillers in PDMS has been of interest, and here a new design in the form of nanocomposite consisting of polyvinyl alcohol/silver nanowire 3D porous composite that is then infiltrated with soft PDMS matrix is demonstrated. The vertically aligned freeze-dried structure within the composite exhibited a remarkable strength increase of up to 3.5 times compared to PDMS alone. The incorporation of hard and soft phases with 3D interfaces effectively hindered fracture propagation within the composite thereby greatly enhancing the stretchability; PVA+AgNW/PDMS nanocomposite demonstrated an excellent recoverability 82.7%. In addition, the silver nanowire network provides sufficient conductivity with small filler concentration of 0.47 vol% that makes PVA+AgNW/PDMS nanocomposite a compelling choice for flexible electronics application requiring a combination of electrical conductivity, high strength, and excellent recoverability.