Preparation and characterization of PEDOT:PSS/poly(acrylamide-co-methacrylic acid) conductive hydrogels

In this work, in-situ free-radical solution polymerization method was used to fabricate poly(3, 4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS)/poly(acrylamide-co-methacrylic acid) (P(AAM-MAA)) conductive hydrogels. The composition and morphology were characterized by FT-IR, Raman, TGA, and SEM, respectively. The visible-light transmittance, electrical conductivity, tensile properties, and strain sensitivity were also tested. The results showed that PEDOT:PSS was well dispersed in the P(AAM-MAA) hydrogel network, and the hydrogel showed good conductivity and transparency (>50%). The introduction of MAA not only improved the electrical conductivity but also enhanced the tensile properties and strain sensitivity of the hydrogel. When the amount of MAA increased from 0wt.% to 2.52wt.%, the conductivity of PEDOT:PSS/P(AAM-MAA) risen from 0.043 S·m−1 to 0.060 S·m−1, and the tensile strength, elongation at break increased from 46 KPa, 76% to 68 KPa, 129%, respectively. PEDOT:PSS/P(AAM-MAA) also has demonstrated excellent linear sensitivity (R2>0.983) (strain: 0-70%). The resistance variation curve showed that the prepared hydrogels can be used as sensors to monitor various small movements of human body through the resistance signal change.