In this work, we have developed a novel absorbent material using chitosan (CS), and further it was structurally modified via reaction with thiocarbaldehyde, forming a Schiff base intermediate. Simultaneously, graphene oxide was functionalized at the C-6 position of CS through an effective esterification process and composited with the incorporation of molybdenum disulfide (MoS₂) nanoparticles to synthesize a hybrid adsorbent material. The resulting material was characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The synthesized adsorbent was subjected to the adsorptive removal of Cu(II) and Cr(VI) ions from dilute solutions. The maximum uptake of 66.66 mg/g for Cu(II) and 76.92 mg/g for Cr(VI) were recorded during the adsorption process, further following pseudo-second-order kinetics adsorptive nature and fitted well with the Langmuir isotherm model. Desorption studies indicated the material’s reusability, and the thermodynamic studies indicated a spontaneity with an endothermic adsorptive nature. These studies highlight the material’s potential as an effective adsorbent as a sustainable approach for efficient environmental remediation.

Bacterial cellulose (BC) is an eco-friendly biopolymer with outstanding structural and functional properties, offering promising applications in sustainable packaging and bio-based materials. In this study, we demonstrate the feasibility of producing BC via spontaneous fermentation, using grape pomace supplemented with sucrose as the sole carbon source, nutrient substrate, and microbial inoculum, without the addition of commercial strains or nitrogen supplements. Fermentation was conducted under static conditions, yielding biofilms with stable structural characteristics and BC production of up to 14.1 g/L, thereby confirming the efficiency of this low-cost, residue-based process. The films obtained exhibited well-organized polymeric networks, with thermal stability in the range of T_g ≈ 159–266 °C and mechanical resistance comparable to or higher than conventional biopolymers. Characterization confirmed reproducible chemical profiles, thermal stability, and measurable variation in mechanical performance, with a tensile strength ranging from 0.0001 to 105 MPa and an elongation at break of 15±5%. The process highlights a resource-efficient and sustainable pathway, adaptable to rural contexts and aligned with circular economic principles. While minor variations among replicates reflected the intrinsic variability of biological systems, mean values and standard deviations demonstrated reproducible physicochemical and mechanical properties. These findings demonstrate that BC derived from agro-industrial residues can be produced under simple, low-input conditions, opening opportunities for scalable valorization in functional and sustainable materials.

Polylactic acid (PLA) is one of the most widely used biopolymers, and it has demonstrated a huge potential for replacing some of the conventional plastics in certain application fields. However, due to a lack of other attributes such as antimicrobial properties and slow degradation rates, it is often blended with other polymers to impart these properties. Chitosan has desirable features including antimicrobial and antioxidant properties, biodegradability and biocompatibility, and environmental friendliness. Thus, it is widely blended with PLA to generate materials that can be applied in various fields. In recent years, PLA/chitosan blend composites and nanocomposites have been produced to develop sustainable and ecofriendly materials that can be suitable in active food packaging, water treatment, air filtration, and biomedical applications. This review provides an overview of the recent advancements in the development of PLA/chitosan blend composites and nanocomposites for various applications. The processing strategies, mechanical and thermal properties, together with utilization in biomedical, air filtration, water treatment, and packaging applications, are provided.

The growing need for sustainable materials has stimulated research into eco-friendly composites, with biochar emerging as an important reinforcement in polymer matrices. Biochar is a carbon-rich material produced by pyrolyzing organic biomass, offering various benefits over traditional fillers, including sustainability, waste reduction, and carbon sequestration. This study explores the effects of bamboo biochar as a hybrid reinforcement on the properties of polylactic acid (PLA)-rice husk composites. The present hybrid composites are prepared by varying the bamboo biochar from 5–25% and have better mechanical properties than PLA and its composite reinforced with a rice husk filler. The tensile, flexural, and compressive strengths of 51.5, 166.0, and 77.5 MPa are measured for the biochar percentage of 10%, representing increases of 73.1, 150.0, and 58.2% compared to PLA, and 158.2, 98.6, and 31% compared to the PLA composite with rice husk. Higher tensile and flexural moduli of 1.46 and 7.34 GPa are observed for 10 and 15%, respectively. However, the impact strength decreases with higher biochar content due to increased rigidity. The material’s hardness increases at higher biochar content due to enhanced stiffness. Thermal transition and degradation points rise due to increased crystallinity from the biochar reinforcement’s nucleation effect. Additionally, the hydrophobic biochar reinforcement reduces water absorption of PLA composite from 3.2 to 1.6%.

In this study, a new plastic film with antiviral and antibacterial properties was developed using modified cassava starch with glycidyltrimethylammonium chloride (GTMAC) and reinforced by crystalline nanocellulose (CNC), called Q-CS/CNC. For comparison, a control film (Q-CS) was produced without the addition of CNC. Elemental analysis revealed a degree of substitution (DS) of 0.552, indicating the replacement of the OH groups of starch by the NR₄⁺ groups of GTMAC during the quaternization reaction. The addition of CNC resulted in significant increases (p < 0.05) of 38.9, 38.2, and 43.1% in thickness, opacity, and water vapor permeability measurements, respectively, compared to Q-CS. Incorporating CNC also contributed to an increase of 43.6% in tensile strength and 109% in stiffness but slightly decreased thermal stability. The Q-CS/CNC film demonstrated efficacy by inactivating 99% of the coronavirus in 1 min and inhibiting the growth of Staphylococcus aureus and Escherichia coli. This action is attributed to the electrostatic interaction of quaternary amino groups, grafted onto starch, with the phospholipid membrane of microorganisms, resulting in the inactivation of these microorganisms. Therefore, these results highlight the potential use of Q-CS/CNC film as antimicrobial packaging, especially against coronavirus.