Noncovalently functionalized multi-walled carbon nanotube with core-dualshell nanostructure for improved piezoresistive sensitivity of poly(dimethyl siloxane) nanocomposites

Poor sensitivity in low pressure regimes (<100 kPa) of pressure-sensitive rubbers (PSRs) is one of their major disadvantages compare to other piezoresistive materials. The reasons induced the poor sensitivity include bad dispersion and week interface of multi-walled carbon nanotubes (MWCNTs) applied in poly(dimethyl siloxane) (PDMS). A novel vinyl-terminated poly(dimethyl siloxane)-poly(phenylmethyl siloxane)-multi-walled carbon nanotubes (V-P-MWCNTs) with core-dualshell nanostructure is fabricated by noncovalently functionalized method. The V-P-MWCNTs as conductive fillers exhibits homogenous dispersion as well as good interfacial interaction in PDMS matrix. Slightly above the percolation threshold (0.19 vol.%), the PDMS-based nanocomposites with 0.2 vol.% of V-P-MWCNTs shows high piezoresistive sensitivity (22.16 × 10−3 kPa−1), high electrical conductivity (5.43 × 10−3 S/m) and low Young's modulus (288.83 kPa). These results demonstrate that the V-P-MWCNTs are of great potential as the conductive fillers for improved piezoresistive sensitivity of PDMS nanocomposites, which can be potentially applied in the flexible touch sensors.