Molecular Structure and Interactions of Chitosan with PVA and TiO₂ in Hydrogel Networks Before and After Freeze-Thaw Process

To visually represent the molecular structure of chitosan and its interactions with PVA and TiO₂, you can create a diagram with the following elements: 1. Chitosan Molecular Structure Represent chitosan's repeating unit: A linear polymer of glucosamine units, with hydroxyl (-OH) and amine (-NH₂) groups. Highlight key functional groups that participate in interactions (e.g., -NH₂ for binding with other molecules). Use a simple structural formula to display the polysaccharide backbone. 2. Interaction with PVA and TiO₂ PVA (Polyvinyl Alcohol): Illustrate the repeating units of PVA with hydroxyl (-OH) groups. Show hydrogen bonding between PVA's -OH groups and chitosan's -NH₂ or -OH groups. Use dashed lines to represent these bonds. TiO₂ (Titanium Dioxide): Represent TiO₂ nanoparticles as small spheres. Show coordination bonds or physical interactions between TiO₂ and chitosan's -NH₂ groups or PVA’s -OH groups. 3. Hydrogel Network Formation Before Freeze-Thaw: Show an amorphous, loosely connected structure of chitosan and PVA chains with TiO₂ dispersed in the matrix. Highlight the initial weak interactions, like hydrogen bonding and van der Waals forces. After Freeze-Thaw: Display a denser, more organized structure due to physical crosslinking during the freeze-thaw process. Use overlapping chains and clusters to show the stronger network, with TiO₂ nanoparticles embedded within. Include arrows to indicate changes in structure (e.g., shrinkage or alignment due to freeze-thaw cycling). Key Visual Design Tips Color Coding: Use distinct colors for chitosan (e.g., green chains), PVA (e.g., blue chains), and TiO₂ (e.g., gray or white spheres). Labels and Legends: Clearly label molecular structures, bonds, and interactions. Side-by-Side Comparison: Place "Before Freeze-Thaw" and "After Freeze-Thaw" structures next to each other for easy comparison. Annotations: Use arrows and text to describe key processes (e.g., hydrogen bonding, physical crosslinking, structural tightening), Diagram illustrating molecular structure of chitosan. Show interactions with PVA and TiO₂. Display chitosan's repeating unit with functional groups. Highlight hydrogen bonds with PVA's -OH. Represent TiO₂ as nanoparticles. Show hydrogel network before and after freeze-thaw processes. Use color coding for clarity. Include labels and legends for educational purposes. Provide side-by-side comparison of structures