Versatile Deprotonation-Induced Exfoliation and Functionalization of Biological Nanofibrils for Actuation and Fluorescence

Biological nanofibrils not only are characteristic of many species of biomasses but also serve as a promising type of sustainable nanomaterials for various applications. However, their production has long relied on an invasive and energy-consuming mechanical shear. A noninvasive and versatile approach remains challenging to exfoliate different types of biomasses into nanofibrils. In this study, we showed a versatile and nonaggressive intercalative deprotonation agent of organic base, which could efficiently deprotonate various biomasses for energy-saving exfoliation and functionalization, including cellulose, chitin, and silk. Both carboxylic nanofibrils and nanofibrils with pristine chemical structures could be produced in high yields through manual shaking or sonication. By further grafting photoresponsive groups via transesterification, intelligent NFs were generated featuring ultraviolet-responsive fluorescence and hydrophilicity. These responsive fluorescence and actuation behaviors promised their potential as green encryption and anticounterfeiting nanomaterials.