(164b) Evaluation of Structural and Photonic Properties of Tunicate-Derived Cellulose Nanocrystals

Cellulose nanocrystals (CNC) are rod-shaped nanomaterials that display a wide range of mechanical and rheological properties depending on the source of the cellulose starting material. CNCs isolated from tunicates, an invertebrate marine animal considered to be an invasive species in many parts of the world, have high aspect ratios and display excellent mechanical properties. In this work, ascidian tunicates (Styela plicata) harvested from floating docks in Charleston, South Carolina were deproteinized, bleached, and treated with sulfuric acid to obtain tunicate CNC (t-CNC). The shape and size of t-CNC rods were characterized from transmission electron microscopy (TEM) images. The aspect ratio of nanocrystal rods were measured to be 145±10 for t-CNCs compared to 24±5 for wood-extracted CNCs. When observed under the polarized optical microscope, aqueous t-CNC suspensions at low concentrations showed fingerprint patterns, the signature of chiral nematic liquid crystalline structures, and maintained the chiral features in the casted dry thin film. According to our UV-visible spectroscopy measurements, dry t-CNC films have absorbance peaks within the visible light spectrum that promotes their function in photonic applications.