Phytic Acid-Functional Cellulose Nanocrystals and Their Application in Self-Healing Nanocomposite Hydrogels

Cellulose nanocrystals (CNCs) have garnered significant attention as a modifiable substrate because of their exceptional performances, including remarkable degradability, high tensile strength, high elastic modulus, and biocompatibility. In this article, the successful adsorption of phytic acid (PA) onto the surface of cellulose nanocrystals @polydopamine (CNC@PDA) was achieved. Taking inspiration from mussels, a dopamine self-polymerization reaction was employed to coat the surface of CNCs with PDA. Utilizing Pickering emulsion, the CNC@PDA–PA nanomaterial was obtained by grafting PA onto CNC@PDA. An environmentally friendly hydrogel was prepared through various reversible interactions using poly(acrylic acid) (PAA) and Fe3+ as raw materials with the assistance of CNC@PDA–PA. By multiple hydrogen bonding and metal–ligand coordination, nanocomposite hydrogels exhibit remarkable mechanical properties (the tensile strength and strain were 1.82 MPa and 442.1%, respectively) in addition to spectacular healing abilities (96.6% after 5 h). The study aimed to develop an innovative approach for fabricating nanocomposite hydrogels with exceptional self-healing capabilities.