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Self-healing gels based on reshuffling disulfide bonds have attracted great attention due to their ability to restore structure and mechanical properties after damage. In this work, self-healing gels with different cellulose nanocrystals (CNC) contents were prepared by embedding the thiuram disulfide bonds into gels via polyaddition. By the reshuffling of thiuram disulfide bonds, the CNC-containing gels repair the crack and recover mechanical properties rapidly under visible light in air. The thiuram disulfide-functionalized gels with a CNC content of 2.2% are highly stretchable and can be stretched approximately 42.6 times of their original length. Our results provide useful approaches for the preparation of dynamic CNC-containing gels with implications in many related engineering applications.

Hydrogels with multifunctional properties have attracted considerable interest owing to their wide range of applications in soft robotics, wearable device development, and tissue engineering. In this study, an adhesive, self-healing, and antibacterial conductive poly­(dopamine methacrylate-co-methacrylatoethyl trimethyl ammonium chloride-co-acrylic acid) (PDDA) hydrogel was prepared by the free-radical copolymerization of dopamine methacrylate (DMA), methacrylatoethyl trimethyl ammonium chloride (DMC), and acrylic acid (AA). The adhesion property of the PDDA hydrogel was explored by regulating the feeding ratios of AA, DMA, and DMC. The hydrogel with a DMA/DMC/AA molar ratio of 1:4:40 exhibited strong adhesion to various materials such as iron, wood, rubber, glass, polytetrafluoroethylene, and plastic. Meanwhile, the hydrogel showed good antibacterial properties, which had a good inhibitory effect against Escherichia coli (37%) and Staphylococcus aureus (44%). In addition, because of its non-covalent bond interactions in the cross-linking network, the hydrogel exhibited excellent self-healing property when damaged. Moreover, the excellent ductility, biocompatibility, and adhesion property of the hydrogel allow better adhesion to the skin surface and conductivity to monitor the physiological activities of the human body by means of the electrical signals recorded using the transformation of strain responses. The self-healing, adhesive, antibacterial, biocompatible, and conductive hydrogel has a wide range of applications in electronic skin and wearable devices.

Wood is a natural, abundant, renewable resource, which is easily processed, has beautiful texture and good mechanical strength, and is widely used for furniture, flooring, decor and building construction. However, wood is vulnerable to moisture and microorganisms, resulting in deformation, cracks, mold and degradation, which causes aesthetic problems and/or shortens the service life of wood products. In this paper, superhydrophobic wood (wood-F) was fabricated by grafting poly(2-(perfluorooctyl)ethyl methacrylate) (PFOEMA) onto wood by atom transfer radical polymerization (ATRP). Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) with an energy-dispersive X-ray spectroscopy (EDS) showed that PFOEMA was successfully grafted onto wood. The resultant wood-F exhibited excellent water resistance with a contact angle (CA) of 156° and hysteresis of 4°. The modified wood also showed abrasion resistance, self-cleaning ability and anti-mold properties, all of which are desirable for various wood products.

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In this work, a simple synthetic method was used to prepare a new type of magnetic dissolving pulp (MDP) @polydopamine (PDA) fibers. The hydroxyl groups of the fibers were converted into carboxyl groups after succinylation. Fe3O4 nanoparticles were grown in situ on the fibers. The prepared MDP@PDA fibers have catalytic reduction efficiency and adsorption performance for methylene blue organic dyes, and it has been thoroughly tested under various pH conditions. Fe3O4@PDA fibers have high reusability, are easy to separate, and regenerate quickly. The catalytic and adsorption efficiency barely decreases after repeated use. The surface of dissolving pulp fibers with a functionalized multifunctional PDA coating is used to create multifunctional catalysts and adsorbent materials. This study presents a very useful and convenient method for the synthesis and adjustment of MDP@PDA fibers, which have a wide range of potential applications in catalysis and wastewater treatment.