A COMPREHENSIVE ASSESSMENT ON THE CHARACTERISTICS OF CELLULOSE ACETATE/SODIUM ALGINATE BIO COMPOSITES AND ITS ANTI MICROBIAL ACTIVITY

Abstract

Cellulose derivatives and their associated polymers represent a cornerstone of sustainable materials and contribute substantially to advancements in green chemistry. In the present study, bio composites were developed by combining sodium alginate, a naturally occurring polysaccharide derived from seaweed with cellulose acetate, an ester derivative of cellulose. Among various fabrication techniques available for composite synthesis, solvent casting was selected due to its simplicity and for its cost effectiveness. To evaluate the physicochemical properties of the resulting bio composites, cellulose acetate and sodium alginate were blended in different ratios and subjected to comprehensive characterization. Surface morphology and structural properties were analysed using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Scanning electron microscopy (SEM). FTIR spectra confirmed the formation of intermolecular crosslinking between cellulose acetate and sodium alginate, as evidenced by the presence of characteristic absorption bands corresponding to both components. XRD data clearly indicated that all four compositions exhibited an amorphous nature, as demonstrated by the crystallinity indices, which consistently suggested the presence of a predominantly disordered structural configuration across all samples and the crystallinity index of sodium alginate experienced a marked increase following the incorporation of cellulose acetate, indicating a significant enhancement in structural order. SEM analysis revealed the complete dispersion of cellulose acetate and sodium alginate to form a smooth surfaced film. Mechanical characterization indicated that the tensile strength of the fabricated bio composites ranged from 1 to 4 N/mm², reflecting moderate structural integrity suitable for potential biomedical and packaging applications. Furthermore, antimicrobial assays demonstrated that while cellulose acetate alone exhibited no observable antimicrobial activity, the incorporation of sodium alginate imparted a modest enhancement in bioactivity. As a result, the resulting composites displayed pronounced inhibitory effects against the fungal strain Aspergillus niger and several pathogenic bacterial species, including Klebsiella pneumoniae, Escherichia coli, Bacillus subtilis, and Staphylococcus albus, thereby underscoring their potential as multifunctional biomaterials.