Understanding the Morphology of Cellulose Nanocrystal Films via Evaporated-Induced Self-Assembly

Cellulose nanocrystals (CNCs) have attracted significant attention in fundamental and applied research due to their unique properties, including exceptional specific strength, high surface area, and optical properties. Although CNC films serve as versatile templates with vast potential for applications in coatings, photonics, and optoelectronic materials, precise control over their self-assembly remains a challenge. This study examines the impact of molecular interactions on CNC self-assembly on film morphology and thermal properties. Using the evaporation-induced self-assembly (EISA) method, CNC films were fabricated via two methods: cellulose acetate-coated and uncoated substrates. The effects of surface treatment and oxidation conditions via hydrogen peroxide on CNC organization and material properties were systematically evaluated. A comprehensive suite of analytical techniques, including Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), and X-ray scattering, was utilized. Coating the glass substrate with cellulose acetate during processing, combined with the presence of hydrogen peroxide, significantly altered the morphology of the CNC composites, leading to noticeable changes in their physicochemical and thermal properties. These findings highlight the impact of substrate modifications on CNC film formation, offering insights into optimizing self-assembly for tailored material properties.