Sustainable acid hydrotropic fractionation for bamboo-based nanofilms with unparalleled hydrophobicity and UV resistance

Bamboo, as an important biomass raw material, has a very favorable prospect for Nature-based Solution. Here we provide a method to prepare bamboo-based lignocellulosic nanofibrils (LCNFs) and films with excellent impedance performances by p -toluenesulfonic acid ( p -TsOH) under mild condition. The combined delignification factor (CDF) and combined hydrolysis factor (CHF) were introduced to regulate the hydrolysis severity. The resultant LCNFs with uniform diameter retained a plentiful reactivity without surface functional group changing. The ascendant thermal stability ( T max > 360 °C) of the LCNFs were also obtained. The films made by the LCNFs can block about 99 % UV light with transparency greater than 50 % which exhibited remarkable UV resistance in both UVA and UVB regions. Furthermore, the films presented excellent hydrophobic stability which showed large contact angles (water, 89–99°) and maintained at 64° after 300 s. These properties make bamboo-based materials substitute bamboo for plastics and can be used in aviation, construction, automotive industry, packaging and many other fields, conforming to international initiatives.