Temperature-responsive hydrogel prepared from N-vinyl-ε-caprolactam Pickering emulsions stabilized by cationic...

Hydrogels show potential for application in the anti-corrosion of food preservation packaging. However, hydrogels capable of modulating the release rate kinetics of preservatives under elevated temperature conditions for food preservation packaging remain underexplored. Herein, cationic cellulose nanocrystals (AH-CNCs) were employed as emulsifiers to stabilize N-vinyl-ε-caprolactam (NVCL) and the temperature-responsive hydrogel was fabricated via free radical polymerization. This novel hydrogel enables control the release rate of preservatives by adjusting the addition amount of AH-CNCs under conditions exceeding the lower critical solution temperature (LCST). Below the LCST, increasing AH-CNC contents systematically enhance the swelling rate, concurrently reducing pore size and augmenting the structural stability of the hydrogel matrix. Upon surpassing the LCST, the release rate of preservative salicylaldehyde (SA) can be controlled by tuning the AH-CNCs contents and leveraging electrostatic adsorption between AH-CNCs with positive properties and negatively charged SA. Notably, fruit visualization assays validated that the temperature-responsive hydrogel matrix effectively extends the shelf life of fruits via dual-mode preservative delivery. Consequently, this temperature-responsive hydrogel demonstrates significant potential for practical implementation in smart food preservation packaging applications.