Carbon Nanotubes and Silica@polyaniline Core-Shell Particles Synergistically Enhance the Toughness and Electrical Conductivity in Hydrophobic Associated Hydrogels

Soft, conductive, and stretchable sensors are highly desirable in many applications, including artificial skin, biomonitor-ing patches, and so on. Recently, a combination of good electrical and mechanical properties was regarded as the most important evaluation criterion for judging whether hydrogel sensors are suitable for practical applications. Herein, we demonstrate a novel carboxylated carbon nanotube (MWCNT-COOH)-embedded P(AM/LMA)/SiO2@PANI hydrogel. The hydrogel benefits from a double-network structure (hydrogen bond cross-linking and hydrophobic connectivity network) due to the role of MWCNT-COOH and SiO2@PANI as cross-linkers, thus resulting in tough composite hydrogels. The obtained P(AM/LMA)/SiO2@PANI/ MWCNT-COOH hydrogels exhibited high tensile strength (1939 kPa), super stretchability (3948.37%), and excellent strain sensitivity (gauge factor = 11.566 at 100-1100% strain). Obviously, MWCNT-COOH not only improved the electrical conductivity but also enhanced the mechanical properties of the hydrogel. Therefore, the integration of MWCNT-COOH and SiO2@PANI-based hydrogel strain sensors will display broad application in sophisticated intelligence, soft robotics, bionic prosthetics, personal health care, and other fields using inexpensive, green, and easily available biomass.