Drastic modification of the piezoresistive behavior of polymer nanocomposites by using conductive polymer coatings

Abstract

We obtained highly conductive nanocomposites by adding conductive polymer poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT/PSS)-coated carbon nanotubes (CNTs) to pristine insulating Polycarbonate. Because the PEDOT/PSS ensures efficient charge transfer both along and between the CNTs, we could attribute the improvement in electrical conductivity to coating. In addition to improving the electrical conductivity, the coating also modified the piezoresistive behavior of the nanocomposites compared to the material with pristine uncoated CNTs: whereas CNT/Polycarbonate samples exhibited a very strong piezoresistive effect, PEDOT/PSS-coated MWCNT/Polycarbonate samples exhibited very little piezoresistivity. We studied this change in piezoresistive behavior in detail by investigating various configurations of filler content. We investigated how this observation could be explained by changes in the microstructure and in the conduction mechanism in the interfacial regions between the nanofillers. Our study suggests that tailoring the piezoresistive response to specific application requirements is possible.

Thermally and electrically conductive multifunctional sensor based on epoxy/graphene composite

“…The host polymer is transformed into conductive composite when the concentration of the conductive phase exceeds the percolation threshold where the conductive fillers overlap and contact each other throughout the matrix. Another mechanism to understand the conduction behavior in a polymeric composite is through a tunneling-transfer mechanism where the conductive nanofillers are very close but not touching each other; the minimum distance between two conductive fillers to observe tunneling effect is 1.8 nm [3].…”

“…Polymeric composite films and sensors developed using carbon nanotubes and graphene possess light weight, flexibility, and stretchability, and promise sensitivity and durability compared to metallic nanoparticles. Multiple studies have investigated the structure-property relations of polymer/ graphene and CNT nanocomposites and films [3,[17][18][19][20][21][22][23]. The minimum concentration of CNTs in a polymer needed to reach percolation threshold (j th ) was theoretically calculated, suggesting that only 3.33% of CNTs contribute to the conductive network at j th [18].…”

Unraveling the Order and Disorder in Poly(3,4-ethylenedioxythiophene)/Poly(styrenesulfonate) Nanofilms

“…Conductive polymers attract significant interest because of their facile tunability in electrical properties and processability, which make them popular for the next generation of flexible electronics. − In conductive polymers, highly anisotropic molecules have high conductivity along their backbone chains, moderate conductivity between chains and low conductivity between widely spaced lamellar planes. , Carrier trapping normally results from structural disorder or amorphous grain boundaries between crystallites. A simple macroscopic electrical measurement cannot sufficiently clarify the complex transport mechanism between crystalline grains.…”

Capacitance measurements on integrated conductors for detection of matrix cracks in GFRP

“…However, resistive monitoring is not possible in unmodified GFRP parts like wind turbine rotor blades due to the lack of material conductivity. Resistive SHM of polymers or GFRP can be achieved with modification of the matrix using conductive nanoparticles [3,[6][7][8]. Particularly for large structures, a modification of the entire matrix is expensive.…”