*2.4. Preparation of Starch*/*NC Composite Films*

Starch/NC composite films were prepared using a solution casting method. A certain amount of NC (5% w/w of starch) was dispersed in 100 mL of deionized water by ultrasonication at 600 W for 5 min; 3 g of starch and 0.9 g of glycerol were subsequently added and the suspension was stirred at 85 ◦C for 1 h. The sample solution was poured onto a PTFE glass plate (24 cm × 12 cm), dried at 60 ◦C for 6 h, and then peeled off and kept at 23 ◦C and 53% relative humidity for at least 7 d prior to testing.
