Never-dried bamboo bleached fibers were used as cellulosesource for preparing CNFs. The method to prepare CNFs is accordingto Chen et al. (Chen et al., 2011a, 2011b, 2011c). 100 mL solu-tion containing purified cellulose fibers (0.1 wt%) was ultrasonicallytreated for 200 min with a common ultrasonic generator (JY99-IID, Ningbo Scientz Biotechnology Co., Ltd., China) at a frequency of19.5–20.5 kHz. Then the upper CNFs suspension was collected.