Transmission Electron Microscopy for Structural Insights into Bacterial Cellulose Nanowhiskers in Ternary Deep Eutectic Solvent

In this study, we used Transmission Electron Microscopy (TEM) to establish that bacterial cellulose formed nanowhisker (BCWN) rod-like structures with distinct short and long morphologies when fabricated in a ternary deep eutectic solvent (TDES) of choline chloride, imidazole, and tannic acid. STEM-EDS confirmed nanowhisker twisting, diameter, elongation, and elemental composition. BCNWs enhanced TDES thermal stability by increasing the decomposition temperature and residual yield. DLS and zeta potential showed particle size enlargement and charge reversal, while DSC indicated a reduced melting temperature and restricted molecular mobility. Thus, TEM not only elucidated cellulose morphology but also provided insights into structural transformations and the reinforcing role of BCNWs in tuning eutectic solvent properties for sustainable nanomaterials and potential polymer electrolyte applications.