As a nonfood crop, sweet sorghum has been extensively
utilized
for sugar production and biomass energy conversion. However, industrial
production generates a significant amount of sweet sorghum skin.
Although paper and cellulose-based films are commonly prepared through
a bottom-up approach to capitalize on their abundant cellulose content.
The bottom-up approach often involves the use of substantial quantities
of chemical reagents, thereby posing a serious threat to environmental
safety. In this study, inspired by the arrangement of traditional
Chinese house roof tiles, we employed a stacking and hot-pressing
preparation strategy to transform sweet sorghum skins into flexible
sweet sorghum films (SF). SF retained the high degree of orientation
of cellulose while obtaining high strength and toughness along with
excellent light transmission properties. In particular, the mechanical
properties of SF in the direction parallel to the fibers are exceptionally
remarkable. The tensile strength measured 796.4 MPa, while the toughness
stands at 7.63 MJ/m3. Additionally, SF exhibited outstanding
optical characteristics, boasting a remarkable light transmission
of 78% and a haze of 60%. Moreover, we established the feasibility
of utilizing SF as a functional material for various applications,
showcasing its potential for optical management, smart wearables,
and electronic devices. Importantly, the successful preparation of
large-size SF unlocked possibilities for their widespread and large-scale
utilization, thus making a valuable contribution to environmental
sustainability.