(200h) Solution Behavior of Cellulose Nanocrystals in Polydisperse Polymer Solutions

The fabrication of cellulose nanocrystals (CNCs) into high-performance materials has gained significant attention as promising example of a renewable, sustainable, and inexpensive resource for advanced applications. Included in their innate “green” characteristics is a list of desirable chemical and mechanical properties: thermal stability, facile functionalization, and high theoretical tensile strength, that have been shown to translate well into macroscopic properties when used as a nanocomposite. All CNC composite materials require a “in-solution” processing step where solution interactions dictate the aggregation, interfacial, and liquid crystalline behavior. However, elucidating solution behavior is non-trivial and poorly reported for complex systems. We characterize the solution behavior of acetylated CNCs under varying solvent conditions with the addition of a polydisperse technical lignin. Lignin is a branching, heterogenous, biopolymer and provides useful insight into the robustness of CNC composite systems as we evaluate aggregation effects across the whole spectrum of loading conditions. Dilute solutions are characterized using Multi-Angle Light Scattering (MALS) and Dynamic Light Scattering (DLS) and it was observed that the addition of CNCs into lignin solutions improved dispersion and rheological properties for carbon fiber spinning. Included in the analysis are SANS experiments that show distinct conformational behavior for lignin as well as cross polarized light microscopy where we observe disperse solutions. Results show promise for using CNCs as a means for tuning complex phase behavior in multi-component polymeric solutions.