Green extraction and isolation of cellulose nanofibrils from orchid (Dendrobium sonia earsakul) stem for wound dressing application

The study proposes a new green extraction method of producing nano fibrillated cellulose (NFC) from softwood pulp (SWP) by using subcritical water/CO2. Subcritical water/CO2 led to a controlled hydrolysis of SWP and the treated SWP was fibrillated by sonication to produce NFC. Effect of process parameters (time, temperature, and pressure) on the crystallinity and thermal properties of NFC was studied to optimize the process conditions for controlled hydrolysis. The influence of the extraction process on the properties of prepared NFC was studied. Nanocellulosic materials were characterized by using field emission scanning electron microscopy, transmission electron microscopy, Fourier‐transform infrared spectroscopy, wide‐angle X‐ray diffraction, and thermo gravimetric analysis. The NFC obtained at optimum process conditions (100 bar, 145°C, and 30 min) showed significantly high crystallinity (66%) and high yield (75–80%) compared to the NFC prepared by conventional mechanical grinding method. The present method of producing NFC uses water and pressurized CO2, and therefore, eliminate use of acids and chemicals. Plasticized poly vinyl alcohol (p‐PVA) based nano composite with NFC shows significant improvement in thermal stability (36%), tensile strength (77%) with reduced water vapor transmission rate as compared to virgin p‐PVA indicating their potential as nanofiller for making bio composites.

Macromolecular inks of nanocellulose-alginate for direct-ink-writing: Functional scaffolds enriched with curcumin extracts.

Green and energy-efficient extraction of cellulose nano-fibrils from rice straw and its coating to improve functional properties of rice straw paperboard made via refiner mechanical pulping

Non-destructive strategy to extract sustainable helix and high-strength Musa core fibers for rapid water conduction and evaporation

Heparin is a critical anticoagulant, yet its purification remains challenging. Most commercial adsorbents are derived from petroleum-based polymers, which may introduce microplastics into the human bloodstream during medical use, posing a potential health risk. Herein, we report a regenerated positively charged cellulose nanofibril (PCCNF)-based hydrogel as a green and efficient alternative for selective heparin extraction. With quaternary ammonium modification, PCCNFs capture ∼88% heparin within 1 min, which outperforms commercial Amberlite IRA-900. We then produce regenerated cationic cellulose (cCell) hydrogels through an ionic liquid (IL) dissolution and regeneration process from PCCNFs, and we demonstrate their high selectivity toward heparin even in the presence of protein contaminants and their excellent reusability over multiple cycles. Finally, the regenerated cCell hydrogels are fabricated into monodispersed spheres via electrospraying for column-based operations, and efficient heparin extraction is verified. This work highlights the potential of regenerated cellulose-based hydrogels as scalable, sustainable substitutes for conventional plastic adsorbents in the recovery of heparin and other polyelectrolytes.