Nacre-mimicking hybrid films of cellulose nanofibrils (CNFs) and silicate platelets, show great potential as high mechanical performance and functional materials has attracting continuously interests. The paper-like vacuum filtration and drying process of the composites is easily scalable to thicker films and even laminates. However, the understanding of nanostructure evolution of self-assembly process is still lacking. In the present study, time-resolved SAXS and WAXS measurements are carried out to investigate the tactoid (stacked platelets) formation, orientation index change of CNFs and silicate platelets during drying. A 2D fitting method for separating signal from components having different textures in the X-ray diffraction pattern is established. Orientation index and MTM tactoid size of the composite show “increase-plateau” tendency as a function of drying time. After changing the solvent to ethanol, the tactoid size increased whereas orientation index decreased. Moreover, the relationship between those nanostructure and mechanical properties is discussed. This fundamental understanding is helpful to the nanostructure control of future high-performance nacre-mimetic bioinspired materials based on renewable CNFs and 2D platelet materials.

X-ray study on self-assembly processing of CNF/MTM nanocomposite films during drying

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.