*2.1. Materials*

The bamboo fiber (BF) used in the experiment was purchased from Studio Buntu (Seoul, Korea) and cut into 2 cm lengths; a bamboo cellulose nanofiber (CNF) dispersion (1 wt.%) was purchased from Chuetsu Pulp & Paper Co., Ltd. (Toyama, Japan); Direct Red 80 (analytical grade, dye content, 25%) was purchased from Sigma Aldrich (Yongin, Korea); and polybutylene succinate (PBS) pellets (BG5000M, 100% PBS) were kindly provided by Anko Bioplastics (Wonju, Korea).
