Self-healing multilayer polyelectrolyte composite film with chitosan and poly(acrylic acid)

Abstract

If self-healing materials can be prepared via simple technology and methods using nontoxic materials, this would be a great step forward in the creation of environmentally friendly self-healing materials. In this paper, the specific structural parameters of the various hydrogen bonds between chitosan (CS) and polyacrylic acid (PAA) were calculated. Then, multilayer polyelectrolyte films were fabricated with CS and PAA based on layer-by-layer (LbL) self-assembly technology at different pH values. The possible influence of pH on the (CS/PAA) × 30 multilayer polyelectrolyte film was investigated. The results show that the interactions between CS and PAA, swelling capacity, microstructure, wettability, and self-healing ability are all governed by the pH of the CS solution. When the pH value of the CS solution is 3.0, the prepared multilayer polyelectrolyte film (CS3.0/PAA2.8) × 30 has fine-tuned interactions, a network-like structure, good swelling ability, good hydrophilicity, and excellent self-healing ability. This promises to greatly widen the future applications of environmentally friendly materials and bio-materials.

Self‐healing and conductivity of chitosan‐based hydrogels formed by the migration of ferric ions

“…Figure was tensile stress–strain curves for CEC/PAA‐Fe 3+ hydrogels with different CEC contents. It could be seen from the figure that elongation at break and breaking strength of the hydrogels did not show a clear uniformity with the change of CEC content, which might be due to the fact that CEC was a rigid macromolecule with both positive and negative opposite charges, not completely uniformly dispersed when CEC content increased . When the CEC content was less than 0.05 g (CEC/PAA = 0.05/1), breaking strength and elongation at break of CEC/PAA‐Fe 3+ hydrogels increased with the increase of CEC content, indicating CEC was uniformly dispersed and the existence of hydrogen bonding and electrostatic interaction among CEC, Fe 3+ , and PAA.…”

“…On the other hand, the hydroxyl, amino, and carboxyl groups of CEC could also be coordinated with Fe 3+, thus forming a CEC/PAA‐Fe 3+ crosslinked network. In addition, when chitosan was dissolved in AA solution, its amino group could be protonated, resulting in positively charged macromolecular chitosan chains, and electrostatic interaction with the PAA chain, thereby acting as a crosslinking agent . Taking Sample‐1 (CEC/PAA = 0.1/1 [w/w], Fe 3+ /AA = 0.5 mol %) as an example, the pH values of solution before and after CEC was added were measured.…”

Bio-inspired self-healing structural color hydrogel

“…Coincidentally, for the purpose of increasing the survivability and lifetime of an organism, the function of self-healing that can spontaneously heal injury and recover functionality in creatures is ubiquitous in nature (21)(22)(23)(24)(25). Inspired by these creatures, researchers have developed numerous self-healing hydrogel materials that fuse together with their homogeneous hydrogels for various important applications (26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37). However, the fusion process of the self-healing hydrogels could also happen in their neighboring nanostructures; this would cause the destruction of the periodic photonic scaffolds.…”

Coating Strategies Using Layer‐by‐layer Deposition for Cell Encapsulation

“…Another work reported the preparation of self‐healing multilayer structures using non‐toxic chitosan and polyacrylic acid. For this system, the self‐healing behavior was equally dependent on an external stimulus: the acidification of chitosan to pH 3 . These works allow envisioning possible applications of self‐healing polyelectrolyte multilayered structures for cell encapsulation.…”