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Self-healing hydrogels with multifunctionality as a type of fascinating material show potential application in various fields, such as biomedicine, tissue engineering, and wearable electronic devices. However, to combine the properties of autonomous self-healing property, high conductivity, excellent mechanical properties, and stimuli-responsive properties for hydrogel is still a great challenge. Herein, we present self-healing conductive hydrogels based on β-cyclodextrin (β-CD), N-isopropylacrylamide (NIPAM), multiwalled carbon nanotubes (CNT) and nanostructured polypyrrole (PPY). Among them, β-CD served as the host molecule, and NIPAM served as the guest molecule, CNT as the physical cross-linker and conducting substrate, and PPY as the highly conductive component, respectively. The obtained hydrogels exhibit high conductivity, self-healing property, flexible and elastic mechanical property and rapid stimuli-responsive property both to temperature and near-infrared (NIR)-light together. The excellent ch...

Biomedical electroactive elastomers with a modulus similar to that of soft tissues are highly desirable for muscle, nerve, and other soft tissue replacement or regeneration, but have rarely been reported. In this work, superiorly stretchable electroactive polyurethane-urea elastomers were designed based on poly(lactide), poly(ethylene glycol), and aniline trimer (AT). A strain at break higher than 1600% and a modulus close to soft tissues was achieved from these copolymers. The mechanisms of super stretchability of the copolymer were systematically investigated. Crystallinity, chemical cross-linking, ionic cross-linking and hard domain formation were examined using differential scanning calorimetry (DSC), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), nuclear magnetic resonance (NMR) measurements and transmission electron microscopy (TEM). The sphere-like hard domains self-assembled from AT segments were found to provide the crucial physical interactions needed for the novel super elastic material formation. These super stretchable copolymers were blended with conductive fillers such as polyaniline nanofibers and nanosized carbon black to achieve a high electric conductivity of 0.1 S/cm while maintaining an excellent stretchability and a modulus similar to that of soft tissues (lower than 10 MPa).

A simple route to size-tunable nanoparticles from the self-assembly of degradable and electrically conductive coil–rod–coil triblock copolymers based on an aliphatic polyester and conducting species is presented. A series of coil–rod–coil triblock copolymers consisting of a middle aniline pentamer (AP) segment and two polycaprolactone (PCL) segments were easily synthesized by a combination of a ring-opening polymerization of CL initiated by an aniline dimer (AD) giving AD-PCL and an oxidative coupling reaction between the AD-PCL and p-phenylenediamine. This strategy avoids the multistep reaction used in previous work. The electroactivity of these copolymers was investigated by UV and cyclic voltammetry. The conductivity of the copolymers was dependent on the AP content and the conductivity mechanism of the triblock copolymers is discussed. Interestingly, these triblock copolymers can undergo self-assembly in selective solvent such as CHCl3 as indicated by NMR and transmission electron microscope (TEM) obs...

Degradable electrically conducting hydrogels (DECHs), which combine the unique properties of degradable polymers and electrically conducting hydrogels, were synthesized by introducing biodegradable segments into conductive hydrogels. These DECHs were obtained by joining together the photopolymerized macromer acrylated poly(d,l-lactide)−poly(ethylene glycol)−poly(d,l-lactide) (AC-PLA-PEG-PLA-AC), glycidyl methacrylate (GMA), ethylene glycol dimethacrylate (EGDMA) network and aniline tetramer (AT) by the coupling reaction between AT and the GMA. The electrical conductivity and swelling behavior of these DECHs were tuned by changing the AT content in the hydrogels, the cross-linking degree, and the environmental pH value. The good electroactivity and thermal stability of these hydrogels were demonstrated by UV−vis spectroscopy, cyclic voltammetry, and TGA tests. The chemical structure and morphology of these polymers were characterized by NMR, FT-IR, SEC, and SEM. These hydrogels possessing both degradabilit...