Multifunctional UV-shielding nanocellulose films modified with halloysite nanotubes-zinc oxide nanohybrid

The design and fabrication of multifunctional UV-shielding materials based on naturally abundant and biodegradable raw materials have far-reaching significance for various practical applications and sustainable development. In the present work, novel multifunctional cellulose nanofibrils (CNFs)/halloysite nanotubes-zinc oxide (HNTs-ZnO) hybrid films with synergic feature of excellent UV-shielding, superhydrophobic properties and thermal stability were firstly fabricated via vacuum-assisted filtration strategy and following hydrophobic modification. The successful immobilization of ZnO nano-protrusions on HNTs surface effectively suppressed the aggregation of ZnO nanoparticles, giving a positive contribution for the UV-shielding performance. Particularly, the CNFs/HNTs-ZnO hybrid films achieved a high UV-blocking efficiency in both UVA (95.7%), UVB (98.7%) and UVC (99.8%). Besides, the filtration membrane template endowed the CNFs/HNTs-ZnO hybrid films with hierarchical rough architecture, and as-fabricated hybrid films presented superhydrophobicity with a contact angle over 155 degrees and simultaneous self-cleaning function. Moreover, the CNFs/HNTs-ZnO hybrid films also displayed an outstanding thermal and UV stability. The findings conceivably indicate that the CNFs/HNTs-ZnO hybrid films provide a versatile way for the development of sustainable multifunctional UV-shielding films and have promising applications in packaging, intelligent windows and other outdoor UV-sensitive materials areas. Graphic abstract