Mixed-linkage (1,3;1,4)-β-D-glucans as rehydration media for improved redispersion of dried cellulose nanofibrils

Improving the redispersion and recycling of dried cellulose nanofibrils (CNFs) without compromising their nanoscopic dimensions and inherent mechanical properties are essential for their large-scale applications. Herein, mixed-linkage (1,3;1,4)-beta-D-glucan (MLG) was studied as a rehydration medium for the redispersion and recycling of dried CNFs, benefiting from the intrinsic affinity of MLG to both cellulose and water molecules as inspired from plant cell wall. MLG from barley with a lower molar ratio of cellotriosyl to cellotetraosyl units was found homogeneously coated on CNFs, facilitating rehydration of the network of individualized CNFs. The addition of barley MLG did not impair the mechanical properties of the CNF/MLG composites as compared to neat CNFs nanopaper. With the addition of 10 wt% barley MLG, dry CNF/MLG composite film was successfully redispersed in water and recycled with well-maintained mechanical properties, while lichenan from Icelandic moss, cationic starch, and xyloglucan could not help the redispersion of dried CNFs.

Automated summary

In this study, mixed-linkage (1,3;1,4)-beta-D-glucan (MLG) from barley was used as a rehydration medium to improve the redispersion and recycling of dried cellulose nanofibrils (CNFs). MLG exhibited an intrinsic affinity to both cellulose and water molecules, similar to plant cell wall. Coating CNFs with MLG facilitated the rehydration of individualized CNFs network. The addition of 10 wt% barley MLG did not affect the mechanical properties of CNF/MLG composites, and the dried CNF/MLG composite film could be successfully redispersed in water and recycled with well-maintained mechanical properties, unlike lichenan, cationic starch, and xyloglucan.