Due to the unmodified surface of CNCCr(NO3)3 with the high aspect ratio and high content of hydroxyl groups on the fiber surface, the CNCCr(NO3)3 tends to intertwine with their neighbor fibers and these networks were caused by the physical entanglement lock between the fibers. Furthermore, the lack of imparting electrostatic stability on CNCCr(NO3)3 resulted in poor stability, leading to agglomeration as compared to the sulfated CNCH2SO4 which remained individually dispersed. A similar observation has been reported by others . As a result, the CNCCr(NO3)3 suspension was unable to maintain its stability after being stored for seven days and obvious precipitation can be seen, while the CNCH2SO4 still remained a milky colloidal suspension with negligible precipitation, as displayed in Figure 7c. In summary, the excellent stability of CNCH2SO4 suspensions was beneficial to reinforce the hydrophilic polymers (such as polyvinyl alcohol). Further studies on the potential reinforcement of composites by the CNCH2SO4 and CNCCr(NO3)3 manufactured in this study are underway.