Recyclable cellulose nanofibrils composite film derived from bamboo fiber tableware waste

Abstract

The world faces a serious environmental pollution from petrochemical plastic. Sustainable green cellulose films can be employed as an alternative to plastic films, thus providing a solution to the pollution caused by the latter. In this study, cellulose nanofibrils (CNF) with low food content were extracted from food solutions of discarded bamboo fiber tableware using micro-nano bubble technology. The CNF were then stabilized in oil-water emulsions to form a biobased CNF-food solution composite film using the solvent casting method. The composite film treated with micro-nano bubbles called post-cleaning bamboo fiber tableware(PS-BFT) exhibited a significantly better mechanical strength, transparency, and thermal performance than those of stained bamboo fiber tableware(S-BFT), and even better transparency and thermal performance than those of clean bamboo fiber tableware(C-BFT). Furthermore, microscopic observations revealed that the films with a high food content exhibited a clear multilayer structure, while those with a lower food content presented only a few agglomerations of food solution-fiber. This confirms the cleaning effect of micro-nano bubbles on the residual food solution in discarded tableware and demonstrates their potential in the high-value utilization of secondary fibers.