Poly(acrylic acid)‐chitosan @ tannic acid double‐network self‐healing hydrogel based on ionic coordination

Abstract

In this work, poly(acrylic) acid-chitosan @ tannic acid-aluminum ion (PAA-CS@TA-Al 3+ ) double-network hydrogel was prepared via prefabrication, blending method, and Al 3+ immersion method. The interaction between chitosan and tannic acid (CS@TA) was analyzed using Fourier transfer infrared spectra and UV-Vis spectra. The UV-Vis spectrum was also used to confirm the formation of ionic coordination in the gel. Then, the possible coordination modes were studied and analyzed. The microscopic pore structure and macroscopic strain behavior of the gel were analyzed using SEM and tensile testing, respectively, which verified that the tensile strength (≈32 KPa) and elongation at break (≈1700%) of the gel primarily resulted from its crosslinking structure. In addition, the gel also demonstrated a good self-healing performance with recovery ≈92.2% at 60 minutes.Hence, the proposed novel self-healing gel can provide inspiration for the preparation of future self-healing gels. K E Y W O R D Schitosan, double-network hydrogel, ionic coordination, self-healing, tannic acid

A Dual Physical Cross‐Linking Strategy to Construct Tough Hydrogels with High Strength, Excellent Fatigue Resistance, and Stretching‐Induced Strengthening Effect

“…Among DC hydrogels, DPC hydrogels [38] attract much more attention due to their excellent stiffness, toughness, anti-fatigue, and selfrecoverability. Diverse physical interactions could be utilized to construct DPC hydrogels, such as hydrogen bonding, [39,40] hostguest interaction, [41,42] ionic coordination (IC), [43,44] HA, [45,46] crystallization, [47,48] chain entanglement, [49,50] and dipole-dipole interaction. [51,52] Inspired by the synergistic enhancement of rigid and flexible networks in DN hydrogels, the synergistic effect of strong and weak interactions is anticipated to endow DPC hydrogels with outstanding mechanical performances.…”

Poly(acrylamide‐co‐acrylic acid)/chitosan semi‐interpenetrating hydrogel for pressure sensor and controlled drug release

“…Due to its inherent biocompatible, biodegradable, nontoxic, antibacterial, and bioabsorbable properties, chitosan (CS) has become one of the most popular chemically doped materials for hydrogels, including semi‐interpenetrating (semi‐IPN) hydrogels of chitosan with polyacrylamide, 21,22 chitosan with poly( N ‐isopropylacrylamide), 23 chitosan with poly(acrylic acid), 24 chitosan with poly(ethylene glycol), 25 and chitosan with poly(vinyl alcohol) 6,26 . The NH 2 groups of chitosan are easily protonated by acid, making CS soluble in acidic solution 27 .…”

Highly tough and rapid self-healing dual-physical crosslinking poly(DMAA-co-AM) hydrogel

“…The strategies to design self-healing hydrogels are mainly based on healing agents, dynamically reversible covalent bonds, or dynamically non-covalent bonds. [36][37][38][39] Up to now, the frequent use of non-covalent bonds to prepare self-healing hydrogels has primarily been based on metal-ligand interactions, [40][41][42][43] hostguest interactions, [44][45][46] hydrophobic interactions, [47][48][49][50] hydrogen bonding, [51][52][53][54][55][56][57] ionic interactions, [58][59][60][61][62] etc.…”