*2.3. Preparation of Nanocellulose (NC)*

For acid hydrolysis, 10 g of the MCC/MD-MCC was dispersed in 100 mL of 60% (*v*/*v*) sulfuric acid. Hydrolysis was conducted at 55 ◦C with constant stirring for 1 h, after which the reaction was stopped by adding cold water (10-fold dilution). The suspension was centrifuged at 5000 rpm for 15 min and dialyzed with distilled water for several days until the dialysate became neutral; the neutral suspension was centrifuged at 10,000 rpm for 10 min to recover the colloidal suspension. The resultant NC is referred to as AH-NC.

For high-pressure homogenization, 1 g of MCC/MD-MCC was added to 100 mL of deionized water and homogenized 4 times at 800 bar using a SCIENTZ-150 high pressure homogenizer (Ningbo Xinzhi Biotechnology Co., Ltd., Ningbo, China). The resultant cellulose suspension was centrifuged at 10,000 rpm for 5 min to recover the precipitate, which was then suspended in deionized water. This process was repeated 3 times. The NC colloidal suspension obtained as the supernatant is referred to as HH-NC.

For high-intensity ultrasonication, MCC/MD-MCC was soaked in deionized water for 24 h with a solid to liquid ratio of 1:100. The suspension was homogenized using the TJS-3000 ultrasonicator (1750 W for 30 min) and subsequently centrifuged at 10,000 rpm for 5 min to recover the precipitate, which was suspended in deionized water. This process was repeated 3 times. The NC colloidal suspension obtained as the supernatant is referred to as US-NC.

The yield of NC was calculated gravimetrically according to Equation (1):

$$\text{Yield } \left( \% \right) = \left( \frac{\text{Weight of NC}}{\text{Weight of MCC}} \right) \times 100\% \tag{1}$$
