Landon Faris and Tyler Swenson, “Optimal Fabrication Methods of Cellulose Nanocrystal Composite Films with Elastic and Magnetic Modification”
Mentor: Chiu Law, Electrical Engineering
Poster #58

Cellulose nanocrystals (CNC) are a material derived from cellulose; a material abundant in nature. CNCs are characterized by their helical microstructures that exhibit useful optical properties. Through evaporation-induced self-assembly (EISA), a brittle film with uniform alignment is created. Different adjustments to the procedure create films with optical properties that are modified with physical strain or an applied magnetic field. With these changes, the film is amendable by external modulations that enable applications in sensors and devices. For magnetic alignment, the enclosure space is small, requiring a smaller container. Consequently, issues arise with composite production. Optimizing the evaporation container, composite size, and evaporation time can create a CNC film with more desirable optical properties. To further enhance the CNC alignment, EISA is performed under a magnetic field generated by a pair of rare earth magnets. For maintaining a high field, the gap must be small which complicates the composite production owing to the limited container size. To add to the uses of CNC nanomaterials, we plan to make the films elastic by chemically modifying them to allow the film to change color in response to applied stress. Furthermore, elastic films will be combined with iron nanoparticles to allow the films to be tuned by a magnetic field. Produced elastic films showed the optical properties of CNC films and changed color from blue to red under physical stress. Additionally, high wettability containers were found to be more suitable for creating composites that do not adhere to their containers after EISA. Finding a more reliable container to produce samples can produce higher quality films that can be reduced in size for fabrication. The application of elastic films allows for an electrical or mechanical actuation or sensing with the optical response of the material as the indicator while enabling easier coupling with electronic systems.