Oppositely charged polyelectrolytes form tough, self-healing, and rebuildable hydrogels

Free Reprocessability of Tough and Self-Healing Hydrogels Based on Polyion Complex

Tough hydrogels with facile processability to reform into various shapes are required in many practical applications. In this work, we reported that a novel, tough, and self-healing physical hydrogel based on polyion complex (PIC) can be dissolved in 4 M NaCl solution to form a PIC solution. The PIC solution can be easily reprocessed into various shapes, such as thin films, sheets, fibers, and capsules, by using simple methods, such as casting and injection, while maintaining excellent mechanical properties comparable to, or even better than, the original hydrogel. The reprocessability and robust mechanical properties of PIC hydrogels are promising for practical applications in soft materials, especially in 3D/4D printing technology.

High Strength Multifunctional Multiwalled Hydrogel Tubes: Ion-Triggered Shape Memory, Antibacterial, and Anti-inflammatory Efficacies

In this study, ion-responsive hydrogen bonding strengthened hydrogels (termed as PVV) were synthesized by one-pot copolymerization of 2-vinyl-4,6-diamino-1,3,5-triazine (VDT), 1-vinylimidazole (VI), and polyethylene glycol diacrylate. The diaminotriazine-diaminotriazine (DAT-DAT) H-bonding interaction and copolymerization of VI contributed to a notable increase in comprehensive performances including tensile/compressive strength, elasticity, modulus, and fracture energy. In addition, introducing mM levels of zinc ions could further increase the mechanical properties of PVV hydrogels and fix a variety of temporary shapes due to the strong coordination of zinc with imidazole. The release of zinc ions from the hydrogel contributed to an antibacterial effect, without compromising the shape memory effect. Remarkably, a multiwalled hydrogel tube (MWHT) fixed with Zn(2+) demonstrated much higher flexural strengths and a more sustainable release of zinc ions than the solid hydrogel cylinder (SHC). A Zn(2+)-fixed MWHT was implanted subcutaneously in rats, and it was found that the Zn(2+)-fixed MWHT exhibited anti-inflammatory and wound healing efficacies. The reported high strength hydrogel with integrated functions holds potential as a tissue engineering scaffold.

Recent strategies to develop self-healable crosslinked polymeric networks

Autonomous self-healable crosslinked materials designed with built-in ability to repair physical damage and cracks can prevent catastrophic failure and thus extend the lifetime of materials.

A multifunctional transparent superhydrophobic gel nanocoating with self-healing properties

A multifunctional green superhydrophobic gel nanocoating with good transparency and stability was obtained through a facile copolymerization reaction. Importantly, this well-designed nanocoating has self-healing superhydrophobicity to face complicated daily life and industry work conditions. It is applicable to various substrates via a simple spray process.