Work

Xanthan Gum/Lignin Double-Interpenetrating Network Cryogels: Preparation, Characterization, and Water Purification Performance

Year: 2026

Type: article

Abstract: The development of multifunctional, bio-based materials capable of simultaneously addressing microbial contamination and inorganic pollutants is of increasing interest for sustainable water purification. In this study, xanthan gum (XG)/lignin(LN) double-interpenetrating network (DN) cryogels were prepared and investigated as porous, multifunctional materials for antimicrobial applications and water purification. The cryogel architecture combines the abundant oxygen-containing functional groups of XG and LN with an interconnected porous network generated under cryogenic conditions. The prepared networks were comprehensively characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), dynamic vapor sorption (DVS), swelling analysis, and uniaxial mechanical testing to evaluate their structural, morphological, physicochemical, and mechanical properties. Their Cu2+ sorption performance was subsequently assessed by atomic absorption spectroscopy (AAS), and the experimental equilibrium data were analyzed using the Langmuir, Freundlich, and Sips isotherm models. The single-network (SN) XG-based materials exhibited Cu2+ sorption capacities of 62.13–109.81 mg/g, whereas the DN cryogels showed higher capacities of 111.87–120.84 mg/g. The Sips model provided the best description of the equilibrium data, with (R2) values of 0.991–0.994 and substantially lower (χ2) values than the Langmuir and Freundlich models, indicating heterogeneous sorption sites with finite saturation capacity. Importantly, the Cu2+-loaded SN and DNs exhibited sorption efficiency toward sulfate ions, demonstrating their potential for sequential contaminant removal. Sulfate sorption capacities reached 694.53 mg/g for the SN.X2/Cu2+ composite and up to 812.53 mg/g for the DN.XL3/Cu2+ composite. In addition, the prepared materials demonstrated antimicrobial activity against two Gram-negative (Escherichia coli, Salmonella Typhimurium) and two Gram-positive (Staphylococcus aureus, Listeria monocytogenes) bacterial strains. The results demonstrate that XG/LN DN cryogels combine effective metal-ion and sulfate sorption with antimicrobial activity, providing promising bio-based platforms for water purification and potentially extending the functional lifetime of the material through sequential contaminant removal.

Source: Gels

DOI: 10.3390/gels12100915

Authors: Maria Marinela Lazar, Doina Humelnicu, Irina Elena Raschip, Raluca-Elena Avram, Maria Valentina Dinu

Institutions: Institutul de Chimie Macromoleculară Petru Poni, Alexandru Ioan Cuza University

Language: English

Topic: Adsorption and biosorption for pollutant removal

Subfield: Water Science and Technology

Field: Environmental Science

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production

Open Access status: gold

Estimated APC paid: $2,534