Development and characterization of biodegradable nanocomposite membrane using chitosan and green ZnO nanoparticles

Abstract

In response to the growing demand for sustainable industrial materials, this study focuses on the development and characterization of novel Chitosan/green ZnO nanocomposite membranes. This study aims to create inexpensive, non-toxic, and biodegradable materials using sustainable sources. Chitosan, extracted from shrimp shells, was combined with ZnO nanoparticles synthesized through a green approach utilizing the invasive plant Hydrilla verticillata. Chitosan was extracted from shrimp shells, following a series of processes: demineralization using 4% HCl, deproteinization with 5% NaOH, and deacetylation with 70% NaOH, achieving a 61% yield and a moderate degree of deacetylation (DDA%) of 70.83%. The green synthesis of ZnO nanoparticles was carried out using an aqueous extract of the invasive plant Hydrilla verticillata, resulting in a yield of 67.5%. Four types of membranes were fabricated via a solution-cast method, incorporating varying ZnO nanoparticle content (0.0, 0.2, 0.5, and 0.8 g) into a fixed amount of chitosan (1.0 g). The transparency of the membranes decreased, and their color changed from off-white to light brown with increasing ZnO content. Characterization techniques, including XRD, FTIR, SEM, and EDS, were employed. XRD spectra confirmed the crystalline nature of both pure chitosan and CS/ZnO nanocomposite membranes. The presence of characteristic ZnO peaks indicated successful nanocomposite formation. The average crystalline size of ZnO NPs was calculated as 27.49 nm. FTIR spectra revealed the presence of functional groups in chitosan and confirmed the incorporation of ZnO NPs within the nanocomposite membranes. SEM images showed a random pore structure on the pure chitosan membrane surface, while these pores were masked by ZnO NPs in the nanocomposite membranes. EDS results confirmed the presence of expected elements (C, O, N, and Zn) in the nanocomposite membranes. The study demonstrates that these novel nanocomposite membranes, derived from sustainable materials, hold promise for various industrial applications due to their unique combination of biodegradability, non-toxicity, and potential for tailored properties through variations in ZnO NP content.