Motshabi Alinah Sibeko

In this study, biocomposite films based on chitosan (CS) and banana peel powder (BPP) were prepared by solution casting with 1, 3, and 5 mass% BPP content. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) were conducted to determine the structure and morphology of the prepared films, while TGA was conducted to evaluate the thermal stability. FTIR spectra of the biocomposites showed the shift in the –OH bonding along the 3235 cm ⁻¹ , suggesting a hydrogen bond interaction between the –OH, –NH from the neat CS and the –OH from the BPP. The XRD results further supported the hydrogen bond interaction, as the addition of BPP resulted in a decrease in the peak intensities and a shift to higher angles as the BPP loading was increased. This was attributed to the decrease in crystallinity of neat CS, caused by the change in the crystal structure of neat CS as the BPP particles penetrated the lattice structure. The SEM images of neat CS showed a smooth surface with cracks, while all the biocomposites showed no cracks. The addition of 1 and 3 mass% of BPP showed well-dispersed BPP aggregates embedded in the surface of CS, which further supported improved interfacial adhesion through the strong hydrogen bonding. The TGA results of the biocomposites showed lower thermal stability with the addition of BPP; the maximum degradation temperature decreased from 280 °C (neat CS) to 265 °C with the addition of 5 mass% BPP. This suggests that BPP disrupts the polymer chain movement within CS, which then leads to reduced crystallinity and thermal stability.

Biopolymer-based materials have gained significant attention as sustainable alternatives for wastewater treatment due to their biodegradability, low toxicity, and high adsorption potential. Despite extensive research on individual materials such as chitosan, cellulose, and alginate, a comprehensive synthesis of global research trends integrating multiple biopolymers remains limited. This study addresses this gap through a large-scale bibliometric analysis of 13,720 publications indexed in the Scopus database from 1995 to 2025. The dataset was systematically analysed using VOSviewer to evaluate publication trends, leading journals, countries, institutions, collaboration networks, and keyword co-occurrence patterns. The results reveal a rapid growth phase after 2016, driven by increasing global demand for sustainable water treatment technologies. China, India, and the United States emerged as the most productive and influential contributors. Keyword analysis highlights adsorption, wastewater treatment, cellulose, and chitosan as dominant research themes, with growing emphasis on composite materials and functional modifications. Beyond descriptive metrics, this study identifies key research gaps, including limited focus on scalability, regeneration efficiency, and real-world application of biopolymer-based systems. The findings provide a comprehensive understanding of the evolution and current direction of the field, offering strategic insights for future research and development of high-performance, sustainable wastewater treatment materials.

Chitosan (CS) is a biodegradable and biocompatible polysaccharide, obtained by the deacetylation of chitin. It has gained significant attention as a versatile material for biomedical applications due to its mucoadhesive properties, ease of chemical modification and intrinsic pharmacological activities. This review synthesizes two decades (2005–2025) of literature, focusing on chemical modifications of chitosan for pharmacological purposes and their therapeutic implications in non-communicable diseases (NCDs) and wound healing. Evidence highlights the roles of chitosan-based materials in anticancer, anti-inflammatory, antidiabetic, antihypertensive, and neuroprotective activities, alongside their integration in advanced wound healing strategies. Clinical trials have demonstrated the translational potential of chitosan-based materials. In general, chitosan-based materials exhibit promising dual functions as bioactive agents and drug carriers, necessitating additional investigation in clinical and regulatory frameworks to accelerate therapeutic adoption. In contrast to other studies, this study offers a mechanistic and integrative viewpoint that links chitosan’s chemical modification techniques with their pharmacological effects and clinical translation potential, providing novel perspectives on structure–activity correlations and therapeutic design.

Chitosan is a natural polymer derived from chitin through the deacetylation process. It has emerged as a key ingredient in sustainable wastewater treatment, due to its biodegradability, non-toxicity, and low cost. This biopolymer possesses abundant functional groups, such as -NH₂ and -OH, that efficiently interact with pollutants. This review offers a comprehensive evaluation of pollutant separation techniques involving chitosan-based materials, including adsorption, membrane filtration, flocculation, and photocatalysis. It further examines the underlying adsorption mechanisms, emphasizing how pollutants interact with chitosan and its derivatives at the molecular level. Special focus is given to various modifications of chitosan, alongside a comparative assessment of different chitosan-based adsorbents (hydrogels, nanoparticles, nanocomposites, microspheres, nanofibers, etc.), highlighting their performance in removing heavy metals, dyes, and emerging organic pollutants. The reviewed performance of these polymeric materials from 2015–2025 not only gives an insight about the recent advancement but also points the need for the design of high-performing chitosan-based adsorbents with applications in real water matrices.

The health and environmental consciousness of waste tires has increased tremendously over the years. This has motivated efforts to develop secondary applications that will utilize tire when they reach the end of their life cycle and limit their disposal in landfills. Among the applications of waste tires which are discussed in this review, the use of rubber crumbs in artificial turf fields has gained worldwide attention and is increasing annually. However, there are serious concerns regarding chemicals that are used in the manufacturing process of tires, which ultimately end up in rubber crumbs. Chemicals such as polycyclic aromatic hydrocarbons (PAH) and heavy metals which are found in rubber crumbs have been identified as harmful to human health and the environment. This review paper is intended to highlight some of the methods which have been used to manage waste tire; it also looks at chemicals/materials used in tire compounding which are identified as possible carcinogenic.