Preparation and Characterization of Bacterial Cellulose-Polyvinyl Alcohol Composite Hydrogels Using ZnCl₂ Hydrates as...

Bacterial cellulose (BC) is highly valued for biomedical and industrial applications due to its exceptional biocompatibility, strength, and biodegradability. Polyvinyl alcohol (PVA) exhibits favorable characteristics, making it an ideal candidate for hydrogel formulation. In this study, BC-PVA composite hydrogels were synthesized by dissolving 1% w/w BC in ZnCl₂ 3H₂O and 10% w/w PVA in ZnCl₂nH₂O, n = 6, 9, 12, and 15. These solutions were combined at BC:PVA weight ratios of 3:1, 1:1, and 1:3, then crosslinking using a glutaraldehyde-acetone solution before immersion in deionized water. The resulting hydrogels exhibited a dense, tightly packed structure with mild to moderate porosity. FTIR analysis confirmed molecular interactions via a broad, reduced O-H stretching band and the appearance of C-H bending vibrations. The water content and swelling ratio ranged from 88.13% to 94.67% and 437.93% to 997.22%, respectively. At a compressive strain of 30%, the compressive strength ranged from 62.28 kPa to 93.16 kPa. This work introduces a novel and efficient method for preparing BC-PVA hydrogels using ZnCl₂ hydrate solvents. Both the ZnCl₂ hydration level and the BC:PVA ratio significantly influenced the structural, water content, swelling, and mechanical properties, offering tunable materials for biomedical or industrial applications.