Aerogels from crosslinked cellulose nano/micro-fibrils and their fast shape recovery property in water

For the first time, we demonstrated that compressed aerogels made from crosslinked native cellulose nano/micro-fibril cellulose (NFC/MFC) show a fast shape recovery property after being immersed in water. The shape recovery degree in other solvents was also measured by the volume change of compressed aerogels. It was also found that the recovery degree strongly depends on the solvent properties. For water, more than 98% of the original shape was recovered in less than 10 s. However, only about 18% of its original shape was recovered by immersing the compressed aerogel in ethanol, and no shape recovery was observed by immersing in a nonpolar solvent, such as toluene. The crosslinked native NFC/MFC network is strong enough to withstand hot water and mechanical agitation (200 rpm mechanical stirring in water). The possible mechanism of shape and volume recovery of compressed NCF/MCF aerogel is discussed.