posted on 2021-11-16, 15:34authored byTae Gon Kim, Hyeon Sik Eom, Jong Hwi Kim, Jik Kyo Jung, Keon-Soo Jang, Seong Jae Lee
Stretchable electrode
materials have attracted great attention
as next-generation electronic materials because of their ability to
maintain intrinsic properties with rare damage when undergoing repetitive
deformations, such as folding, twisting, and stretching. In this study,
an electrically conductive PDMS nanocomposite was manufactured by
combining the hybrid nanofillers of carbon nanotubes (CNTs) and silver
nanowires (AgNWs). The amphiphilic isopropyl alcohol molecules temporarily
adhered simultaneously to the hydrophobic CNT and hydrophilic AgNW
surfaces, thereby improving the dispersity. As the CNT/AgNW ratio
(wt %/wt %) decreased under the constant nanofiller content, the tensile
modulus decreased and the elongation at break increased owing to the
poor interaction between the AgNWs and matrix. The shear storage moduli
of all nanocomposites were higher than the loss moduli, indicating
the elastic behavior with a cross-linked network. The electrical conductivities
of the nanocomposite containing the hybrid nanofillers were superior
to those of the nanocomposite containing either CNT or AgNW at the
same filler content (4 wt %). The hybrid nanofillers were rearranged
and deformed by 5000 cyclic strain tests, relaxing the PDMS matrix
chain and weakening the interfacial bonding. However, the elastic
behavior was maintained. The dynamic electrical conductivities gradually
increased under the cyclic strain tests due to the rearrangement and
tunneling effect of the nanofillers. The highest dynamic electrical
conductivity (10 S/m) was obtained for the nanocomposite consisting
of 2 wt % of CNTs and 2 wt % of AgNWs.