*2.2. Preparation of BF/CNFs*

The bamboo fiber and CNF composite were readied using a thermocompression method. First, 2 g of bamboo fiber was immersed in 50 mL of a CNF dispersion solution of different concentrations (0–2 w·v <sup>−</sup><sup>1</sup> %), stirred sufficiently, and then adequately dehydrated by hand in a 3 × 10 cm frame. Afterward, the BF/CNF mixture was thermocompressed with a mini hot press (QM900S, Qmasys, Uiwang, Korea). BF/CNF preforms were prepared by varying the compression temperatures at 25 ◦C, 60 ◦C, 80 ◦C, 120 ◦C, 160 ◦C, and 180 ◦C to find the optimum thermocompression temperature. Moreover, BF/CNF preforms were produced with different compression times for 1, 2, 3, 5, 10, and 15 min to optimally establish the thermocompression time. The thermocompression pressure in all experiments was fixed at 20 MPa. BF/CNFs with different CNF contents were denoted as BF/CNFn, where n denotes the wt.% of CNFs based on BF weight. Ten samples of BF/CNFs were prepared through single preforming process and used for tensile testing and characterization.
