# Preparation and Characterization of Bacterial Cellulose–Polyvinyl Alcohol Composite Hydrogels Using ZnCl2 Hydrates as Solvent

## TL;DR

This paper describes a new method to create BC-PVA composite hydrogels using ZnCl2 hydrates, which could be useful for biomedical or industrial applications due to their tunable properties.

## Contribution

A novel and efficient method for preparing BC-PVA hydrogels using ZnCl2 hydrate solvents is introduced.

## Key findings

- The hydrogels exhibited water content ranging from 88.13% to 94.67% and swelling ratios from 437.93% to 997.22%.
- Compressive strength at 30% strain ranged from 62.28 kPa to 93.16 kPa.
- FTIR analysis confirmed molecular interactions between BC and PVA in the composite hydrogels.

## Abstract

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 ZnCl2
nH2O, 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.