Lignin nanoparticles enable recyclable paper to rival plastic packaging
A Pickering emulsion strategy unites water resistance, oil repellency, biodegradability, and recyclability in paper-based materials
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A Pickering emulsion strategy unites water resistance, oil repellency, biodegradability, and recyclability in paper-based materials
view moreCredit: Key Laboratory of Bio-based Material Science and Technology (Ministry of Education), College of Materials Science and Engineering, Northeast Forestry University, Harbin 150040, China
The global push to reduce plastic waste has intensified interest in paper as a sustainable packaging material. Derived from renewable plant fibers, paper is biodegradable, recyclable, and widely available. However, its intrinsic porosity and hydrophilicity result in poor resistance to water and oil, severely limiting its use in food and consumer packaging. Conventional solutions, such as fluorinated coatings or polyethylene laminates, improve barrier properties but undermine recyclability and introduce environmental concerns.
In a study now available in Journal of Bioresources and Bioproducts, researchers present a new coating strategy that addresses these long-standing challenges by integrating biodegradable components into a lignin nanoparticle–stabilized Pickering emulsion. The approach leverages the amphiphilic nature of lignin nanoparticles to stabilize an oil-in-water emulsion composed of polyvinyl alcohol (PVA) and stearic acid (SA), forming a multifunctional coating that enhances paper performance without sacrificing environmental compatibility.
In the reported system, PVA serves as a hydrophilic, film-forming polymer in the aqueous phase, providing mechanical reinforcement and oil resistance through a dense hydrogen-bonded network. Stearic acid, a naturally derived fatty acid, acts as the hydrophobic oil phase, imparting water repellency. Lignin nanoparticles, prepared through a solvent-exchange self-assembly process, irreversibly adsorb at the oil–water interface, stabilizing the emulsion without synthetic surfactants. This Pickering emulsion design enables the uniform dispersion of hydrophobic components within a water-based coating system.
When applied to paper substrates, the emulsion forms a continuous and compact coating layer that seals surface pores and creates a synergistic barrier against both water and oil. The coated paper exhibits a water contact angle exceeding 110°, a Cobb 60 value below 18 g/m², and a Kit oil resistance rating above 9/12—levels comparable to those of commercially used plastic-coated papers. At the same time, tensile strength and wet strength are significantly improved, allowing the paper to maintain structural integrity even after prolonged water exposure.
Beyond barrier and mechanical performance, the study places strong emphasis on end-of-life considerations. Unlike conventional plastic-coated papers, the reported coating can be removed through a simple hot-water repulping process. During recycling, PVA dissolves, stearic acid melts and disperses, and lignin nanoparticles are released, enabling clean recovery of cellulose fibers without degrading recycled paper quality. Soil burial tests further demonstrate that the coated paper fully degrades within approximately 120 days, while polyethylene films show no observable degradation under identical conditions.
The coated paper also demonstrates functional advantages in food preservation. Packaging tests using fruits such as bayberries, grapes, and cherry tomatoes show that the coating effectively reduces moisture loss by lowering water vapor transmission, extending freshness compared with uncoated paper. These results suggest potential applications in fresh produce and food packaging, where moisture control is critical.
By combining biomass-derived materials with Pickering emulsion technology, the reported strategy provides a scalable and environmentally benign route to high-performance paper packaging. While further optimization is needed—particularly in simplifying lignin nanoparticle production and improving gas barrier properties—the work illustrates how renewable nanomaterials can help bridge the performance gap between paper and plastics. As regulatory pressure and consumer demand continue to drive the transition toward sustainable packaging, such multifunctional, recyclable coatings may play a key role in enabling paper to replace plastics in demanding applications.
Journal
Journal of Bioresources and Bioproducts
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Lignin Nanoparticle Stabilized Pickering Emulsion Coating for Fabricating Water- and Oil-Proof, Biodegradable, and Recyclable Paper
Article Publication Date
27-Jan-2026
Phytic acid–driven structural engineering unlocks high-performance lignin-based carbon aerogel supercapacitors
Spherical architecture and dual phosphorus–sulfur doping synergistically elevate biomass-derived energy storage materials
Journal of Bioresources and Bioproducts
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Spherical architecture and dual phosphorus–sulfur doping synergistically elevate biomass-derived energy storage materials
view moreCredit: School of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China
The global transition toward renewable energy systems such as wind and solar power has intensified the need for advanced energy storage technologies capable of balancing intermittency while maintaining long operational lifetimes. Among various candidates, supercapacitors have attracted sustained attention due to their high power density, rapid charge–discharge capability, and exceptional cycling stability. However, their broader deployment remains constrained by the performance limitations and environmental costs associated with conventional electrode materials.
In this context, biomass-derived carbon aerogels have emerged as a promising alternative, offering renewable sourcing, tunable microstructures, and compatibility with green manufacturing pathways. Lignin, one of the most abundant aromatic biopolymers on Earth and a major byproduct of the pulp and paper industry, represents an especially attractive carbon precursor. Yet transforming lignin into high-performance supercapacitor electrodes requires precise control over both pore architecture and surface chemistry.
The newly reported work addresses this challenge by developing a synergistic structure–doping regulation strategy for lignin-based carbon aerogels. Magnesium lignosulfonate, which inherently contains sulfur, was employed as the primary carbon source, while sodium alginate served as a natural gel-forming agent. Phytic acid played a dual role: acting simultaneously as a phosphorus dopant and as an acidity regulator that directs gelation behavior and structural evolution.
During freeze-drying and subsequent carbonization, phytic acid promoted the formation of uniform spherical hierarchical structures within the aerogel matrix. These spheres, enriched with phosphorus and oxygen species, effectively confined heteroatoms while increasing interlayer spacing and accessible surface area. High-temperature treatment further interconnected the pore network, yielding a mesopore-dominated architecture favorable for fast electrolyte ion transport.
Electrochemical evaluation revealed that the optimized carbon aerogel, prepared at a specific precursor ratio and carbonized at 700 °C, achieved a high specific capacitance of 362 F g⁻¹ at 0.5 A g⁻¹. When assembled into a symmetric supercapacitor device, it delivered an energy density of 40.1 W h kg⁻¹ at a power density of 700 W kg⁻¹, while retaining 82.5% of its capacitance after 20,000 charge–discharge cycles. These metrics compare favorably with many previously reported lignin-derived carbon materials.
Mechanistic analysis attributes this performance to the cooperative effects of structural hierarchy and dual heteroatom functionality. The spherical mesoporous framework facilitates efficient electric double-layer formation and rapid ion diffusion, while phosphorus- and sulfur-containing functional groups introduce additional pseudocapacitive contributions through reversible surface redox reactions. Together, these features overcome the traditional trade-offs between power capability, energy density, and cycling stability that often limit carbon-based supercapacitors.
Beyond performance metrics, the study highlights a sustainable materials design philosophy. By exploiting the intrinsic sulfur content of magnesium lignosulfonate for in situ self-doping and using phytic acid as a multifunctional additive, the approach minimizes chemical inputs and simplifies processing. This strategy not only advances the practical utilization of industrial lignin waste but also provides a generalizable framework for designing high-performance biomass-derived energy storage materials.
Journal
Journal of Bioresources and Bioproducts
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Synergistic Enhancement of Electrochemical Performance in Lignin-Based Carbon Aerogel Supercapacitors through Phytic Acid-Induced Spherical Structure Formation and Dual P/S Heteroatom Doping
Article Publication Date
27-Jan-2026
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