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.

Biocomposites have recently received more attention because of raising environmental awareness and the drive toward sustainable technologies. The most common biodegradable polymer is poly(lactic acid) (PLA), which has an excellent balance of physical and rheological properties, but there is some limit to its usage. PLA properties can be improved by adding different types of fibers or fillers that come from agricultural waste. In this study, corn cob and lavender stem were used to reinforce PLA without any coupling agent, and the properties of the composites were investigated. The melt flow rate (MFR) values decreased with the corn cob content and increased with the addition of lavender stem. Mechanical tests showed that the tensile and flexural modulus of the composites increased and the strengths decreased with the reinforcement material content. The rigidness of PLA slightly decreased with the addition of fillers. There was no significant effect on the thermal properties. The unremarkable improvement of the reinforcement was due to the lack of appropriate adhesion of the two phases. The structure of the compounds was found to be homogenous on the scanning electron microscopy (SEM) micrographs. The incorporation of corn cob and lavender stem can reduce the production cost of materials.

This study demonstrated, for the first time, the successful formation of porous paramylon esters, which were made from euglenoid polysaccharide known as paramylon and short-chain fatty acids, through supercritical CO₂ processing. By maintaining a constant ester functional group attached to the paramylon and varying its proportion, distinct porous structures were selectively produced. Solubility parameter estimations indicated that changes in esterification had no significant effect on the solubility of the paramylon esters used in the experiment. Thus, these structural differences are likely attributed to variations in the viscoelastic properties of paramylon esters under supercritical CO₂ conditions. Furthermore, thermal conductivity measurements revealed reductions of up to 20%. Intriguingly, substantial decreases in thermal conductivity were observed even at low foaming ratios, achieved through precise control of the porous structure.

This study presents for the first time a sustainable approach to hydrophobic modification of nanocellulose/chitosan bioaerogels using beeswax emulsion. The incorporation of beeswax into the aerogel matrix resulted in increasing the density from 35.1 to 298 mg/cm³, while the porosity decreased from 96.4 to 62%. Fourier transform infrared spectroscopy (FT-IR) analysis confirmed the successful integration of beeswax into the nanocellulose/chitosan matrix, with distinct peaks corresponding to the characteristic functional groups of beeswax, such as C–H stretching vibrations, further validating the hydro - phobic modification. The mechanical properties showed increased hardness, from 0.24 to 0.95 N/mm², indicating that higher beeswax content enhanced the rigidity of the aerogels. Contact angle measurements confirmed a dramatic improvement in hydrophobicity, with angles increasing from 47.68 to 134.40 and 128.11° for NC/CH 60-40-15. Water absorption capacity decreased from 17.5 g/g in the control sample to 8 g/g at the highest beeswax concentration, while oil absorption increased significantly, with fresh engine oil absorption rising from 3 to 45 g/g and used engine oil absorption from 2.5 to 40 g/g respectively. These results confirm the successful green modification of bioaerogels using beeswax, providing a sustainable and eco-friendly approach that enhances hydrophobicity, mechanical strength, and selective absorption properties.

The widespread use of cellulose nanofiber (CNF)-based aerogels is hindered by their limited flame retardancy and mechanical properties. This study addresses these challenges by developing cellulose nanofiber/sodium alginate/fly ash (CNF/SA/FA) aerogel through a one-pot method, utilizing industrial waste fly ash (FA) as a reinforcing material. Various characterization and analytical techniques were employed to evaluate the properties of the CNF/SA/FA aerogel. The findings have revealed that resulting aerogel exhibited excellent thermal insulation performance, with a thermal conductivity of 0.485 W/(m·K), along with an impressive compressive strength of 88.4 kPa and favorable shape processability. Vertical combustion tests demonstrated a V-0 rating, indicating superior flame retardancy, and the aerogel achieved a remarkable 79.16% residual carbon, confirming their effective heat shielding capabilities. Notably, the incorporation of FA significantly enhanced both the thermal and mechanical properties of the composite aerogel, presenting a sustainable and effective solution to optimizing the properties of aerogel for thermal insulation.