Physicochemical, Morphological, and Microstructural Characterisation of Bacterial Nanocellulose from Gluconacetobacter xylinus BCZM

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Abstract

The physicochemical, morphological, microstructural, bulk chemical, and thermal characterization of bacterial nanocellulose (BNC) isolated from Gluconacetobacter xylinus BCZM was performed in this study. The morphological and microstructural analyses of the transparent white BNC product is characterized by an asymmetrically oriented and dense network of fibrils with an average diameter of 200 nm. Energy dispersive X-ray (EDX) analysis revealed the elements carbon (C = 70.10 wt.%), oxygen (O = 23.10 wt.%), and sodium (Na = 6.8 wt.%). Functional group analysis revealed characteristic cellulose peaks observed at 3272.94 cm⁻¹, 2922.91 cm⁻¹, 1147.91 cm⁻¹, and 929.06 cm⁻¹ in the chemical structure of BNC. X-ray diffraction (XRD) confirmed that BNC consists primarily of pure cellulose, based on the four broad peaks detected at 2θ = 6.24°, 14.70°, 17.24°, and 23.08°. The peaks are attributed to the amorphous and crystalline regions of the diffraction planes characteristic of cellulose. Thermal analysis revealed BNC experienced significant thermal degradation from 30°C to 700°C mainly due to the cellulose dehydration, decomposition, and depolymerization reactions. Total mass loss (ML) was 57.24% whereas the residual mass (RM) was 42.76%. The findings indicate that the synthesized BNC is potentially useful for high crystalline, porous, and lower temperature cellulose applications.

Acknowledgments

The authors greatly appreciate Universiti Teknologi Malaysia (UTM) for supporting this research under the National Research and University Grant (RUG). Further acknowledgement goes to Bauchi State University Gadau, in Bauchi State, Nigeria. The technical assistance of the Hydrogen and Fuel Cell Laboratory and Institute of Future Energy at Universiti Teknologi Malaysia (Skudai Campus) and the University Industry Research Laboratory are also gratefully acknowledged.