Insight on the Mechanical Properties of Facile Hydrophobic-Barrier-Patterned Bacterial Nanocellulose via Self-Bonding Mechanism

Enhancing the mechanical and structural properties of bacterial nanocellulose (BNC) is key to its use in sustainable nanocomposites. This study employed a hot-press drying method with hydrophobic barriers, folding BNC into four layers and pressing with carbon fiber and Teflon sheets. At 120 °C, carbon fiber-pressed BNC achieved a tensile strength of 43.91 N/mm², 13.84% higher than oven-dried samples and 43.87% higher than Teflon-pressed samples. Scanning electron microscopy (SEM), KLA-Zeta, and atomic force microscopy (AFM) analyses revealed improved self-bonding and surface roughness. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) confirmed increased crystallinity and altered hydrogen bonding, enhancing stiffness and structural stability. Optical and thermal tests showed carbon fiber-pressed BNC was less transparent with moderate heat resistance, while Teflon-treated samples remained clear with higher thermal stability. These findings demonstrate that patterned hot pressing strengthens BNC's self-bonding, advancing its potential for use in structural nanocomposites, flexible electronics, and biocompatible scaffolds.