(421a) On the Potential of Cellulose Hydrogels for Addressing Issues of Environmental Concern

In tribute to Dr. Carson Meredith’s pioneering contributions to sustainable materials and interfacial engineering, this work introduces a novel strategy for cellulose dissolution and regeneration to develop functional materials from lignocellulosic sources that address critical environmental challenges such as water remediation, pest control, and reduced agrichemical inputs in food production.

Traditional methods for producing regenerated cellulose rely on harsh solvents like carbon disulfide (viscose process) or N-methylmorpholine N-oxide (Lyocell process), limiting scalability and environmental compatibility. To overcome these challenges, we developed a low-energy, chemical-free approach involving mechanical fibrillation of lignocellulosic biomass to reduce cellulose’s degree of polymerization, enabling dissolution in cold NaOH/urea systems.

The method is compatible with various feedstocks—including hardwood, softwood, soybean hulls, and spent hops—and accommodates both pristine and lignin-containing fibers. Resulting microfibrillated cellulose (MFC) was regenerated into hydrogel beads and pellets using acid and salt coagulation baths. Composite formulations with chitosan and Tara gum allowed for tunable porosity, morphology, and interfacial adsorption/desorption properties.

These hydrogels were loaded with fertilizers and pesticides and evaluated under greenhouse conditions for controlled-release performance. Surface modifications further optimized delivery profiles, offering an eco-friendly alternative to plastic-based agricultural inputs.

Additionally, the high surface area and tailored chemistry of the MFC hydrogels enabled efficient adsorption of emerging water contaminants such as pharmaceuticals, dyes, and heavy metals. This dual functionality underscores their potential in both agricultural and water remediation applications. This research supports circular bioeconomy goals and reflects Dr. Meredith’s enduring legacy in green materials innovation.