Junrong Li,Liangjing Fang,William R. Tait,Luyi Sun,Lihong Zhao,Liying Qian
Conductive composite hydrogels based on sodium carboxymethyl cellulose (CMC) and polyaniline (PAn) were prepared via the semi-interpenetrating polymer network (semi-IPN) method, using glycerol diglycidyl ether (GDE) as the crosslinking agent. The structures of the resulting composite hydrogels were characterized by 13C-NMR, FT-IR, and SEM. The composite hydrogels with various concentrations of CMC presented a similar swelling kinetic behaviour and a relatively high swelling ratio. With increasing CMC concentration, both the compressive fracture stress and modulus of the composite hydrogels improved gradually. Though the modulus of the composite hydrogels increased with more GDE added, the compressive fracture stress decreased when the crosslinking density was too high. The electrical conductivity of the composite hydrogels increased first and then decreased slightly with increasing dosages of CMC and GDE. Doping with aromatic sulfonate is a good approach to improve the conductivity of the composite hydrogels and the conductivity reached 6.31 × 10−3 S cm−1 after doping with sodium benzene sulfonate (BSNa).
A biocompatible, flexible, yet robust conductive composite hydrogel (CCH) for wearable pressure/strain sensors has been achieved by an all-solution-based approach. The CCH is rationally constructed by in situ polymerization of aniline (An) monomers in the polyvinyl alcohol (PVA) matrix, followed by the cross-linking of PVA with glutaraldehyde (GA) as the cross-linker. The unique multiple synergetic networks in the CCH including strong chemical covalent bonds and abundance of weak physical cross-links, i.e., hydrogen bondings and electrostatic interactions, impart excellent mechanical strength (a fracture tensile strength of 1200 kPa), superior compressibility (ε = 80%@400 kPa), outstanding stretchability (a fracture strain of 670%), high sensitivity (0.62 kPa–1 at a pressure range of 0–1.0 kPa for pressure sensing and a gauge factor of 3.4 at a strain range of 0–300% for strain sensing, respectively), and prominent fatigue resistance (1500 cycling). As the flexible wearable sensor, the CCH is able to monitor different types of human motion and diagnostically distinguish speaking. As a proof of concept, a sensing device has been designed for the real-time detection of 2D distribution of weight or pressure, suggesting its promising potentials for electronic skin, human–machine interaction, and soft robot applications.
危险品化学品经营许可证（带存储）