Electrically Conductive Silicone-Based Nanocomposites\nIncorporated with Carbon Nanotubes and Silver Nanowires for Stretchable\nElectrodes

Abstract

Stretchable electrode\nmaterials have attracted great attention\nas next-generation electronic materials because of their ability to\nmaintain intrinsic properties with rare damage when undergoing repetitive\ndeformations, such as folding, twisting, and stretching. In this study,\nan electrically conductive PDMS nanocomposite was manufactured by\ncombining the hybrid nanofillers of carbon nanotubes (CNTs) and silver\nnanowires (AgNWs). The amphiphilic isopropyl alcohol molecules temporarily\nadhered simultaneously to the hydrophobic CNT and hydrophilic AgNW\nsurfaces, thereby improving the dispersity. As the CNT/AgNW ratio\n(wt %/wt %) decreased under the constant nanofiller content, the tensile\nmodulus decreased and the elongation at break increased owing to the\npoor interaction between the AgNWs and matrix. The shear storage moduli\nof all nanocomposites were higher than the loss moduli, indicating\nthe elastic behavior with a cross-linked network. The electrical conductivities\nof the nanocomposite containing the hybrid nanofillers were superior\nto those of the nanocomposite containing either CNT or AgNW at the\nsame filler content (4 wt %). The hybrid nanofillers were rearranged\nand deformed by 5000 cyclic strain tests, relaxing the PDMS matrix\nchain and weakening the interfacial bonding. However, the elastic\nbehavior was maintained. The dynamic electrical conductivities gradually\nincreased under the cyclic strain tests due to the rearrangement and\ntunneling effect of the nanofillers. The highest dynamic electrical\nconductivity (10 S/m) was obtained for the nanocomposite consisting\nof 2 wt % of CNTs and 2 wt % of AgNWs.