Cellulose Nanocrystals Extracted from Grape Pomace with Deep Eutectic Solvents and Application for Self-Healing Nanocomposite Hydrogels

In the progress of red-winemaking, eco-friendly, facile, and efficient reutilization of grape pomace is an important issue for sustainable industrial processes. In this manuscript, cellulose nanocrystals (CNCs) as extensive and expensive nanomaterials, are efficiently extracted from grape pomace by using deep eutectic solvents. Moreover, the obtained CNCs as the renewable reinforcing agent are successfully fabricated of self-healing nanocomposite hydrogels. The self-healing (93.5%) and mechanical strength (4.77 MPa) in hydrogels are outstandingly improved by the addition of functional CNCs, in which abundant carboxyl functional groups are modified by in situ esterification in the process of extracting CNCs. Importantly, these strain-sensitive and self-healing nanocomposite hydrogels can be further used as flexible strain sensors to detect human motion.