Cellulose is lack of UV-blocking and antibacterial properties, which have limited its application. In this work, the nanoscale lignin with high content of hydroxyl groups and small particle size in prehydrolysate was isolated and used as a green reinforcement ingredient for fabrication of cellulose nanofibril (CNF) films with excellent mechanical properties, as well as UV protection and antibacterial capabilities. Cryogenic transmission electron microscopy (Cryo-TEM) and nuclear magnetic resonance analyses showed that the resulting lignin was in the form of nanoparticles (6–12 nm) with high phenolic hydroxyl contents (4.9 mmol/g). The optimum lignin inclusion rate of 5% allowed it to reinforce CNF composite film, increasing its tensile strength from 108.5 to 143.3 MPa. In addition, the film exhibited excellent UV protection capabilities. It blocked 91.5% of UV-A and 99.9% of UV-B light. Finally, the resulting lignin-based CNF films exhibited antibacterial activities against both Escherichia coli and Streptococcus hemolyticus. This work demonstrates the utility of nanoscale lignin from prehydrolysate can be used to produce cellulose-based composite films with valuable properties.

纤维素缺乏紫外线阻隔和抗菌特性，限制了其应用。在这项工作中，分离出具有高羟基含量和预水解产物中小粒径的纳米级木质素，并将其用作绿色增强成分，以制备具有优异机械性能以及紫外线防护和抗菌能力的纤维素纳米原纤维（CNF）薄膜。 。低温透射电子显微镜（Cryo-TEM）和核磁共振分析表明，所得木质素呈纳米颗粒形式（6–12 nm），具有较高的酚羟基含量（4.9 mmol / g）。木质素最佳掺入率为5％，可以增强CNF复合膜，将其拉伸强度从108.5 MPa增加到143.3 MPa。另外，该膜表现出优异的紫外线防护能力。它阻挡了91.5％的UV-A和99.9％的UV-B光。最后，所得的木质素基CNF膜对两种细菌均表现出抗菌活性。大肠杆菌和溶血链球菌。这项工作证明了来自预水解产物的纳米级木质素的实用性可用于生产具有有价值特性的纤维素基复合膜。