Volume 21 Issue 1

Wood treatments involving chemical reactions are increasingly common in the construction industry, with acetylation being one of the most widely applied methods. In this study, European beech wood (Fagus sylvatica L.) was modified using acetylation in both traditional liquid phase (LP) and gas phase (GP) under varying temperatures (100 to 130 °C) and reaction times (1 to 4 h). The two methods were compared based on weight percentage gain (WPG), bulking coefficient (BC), water-related properties, and chemical changes confirmed by Fourier transform attenuated total reflectance infrared (FTIR-ATR) spectroscopy. The results showed that LP acetylation achieved the highest WPG (19.6%), while GP acetylation provided comparable results under higher temperatures and extended reaction times. Both methods significantly reduced equilibrium moisture content, water absorption, and volumetric swelling, thereby enhancing dimensional stability compared to reference (REF) samples. FTIR analysis confirmed substitution of hydroxyl groups by acetyl groups in both phases. Despite slightly lower WPG values in some regimes, GP acetylation provided similar improvements in water-related properties with reduced consumption of acetic anhydride (AAH). This indicates its strong potential for industrial applications, although further research is necessary to optimize the process for large-scale European beech wood components.

This study investigated the production of particleboards by incorporating recycled polyethylene terephthalate (PET) powder into Pinus spp. particles, using epoxy resin as an adhesive at 5% and 10% levels. The panels were manufactured and tested in accordance with ABNT NBR 14810-2 (2024) and further evaluated under EN 312 (2003) and ANSI A208.1 (2016) standards. The results demonstrated that both the increase in adhesive content and the incorporation of PET powder contributed to significant improvements. Compared with literature data on panels without PET, the addition of recycled PET reduced moisture content (MC), thickness swelling (TS), and water absorption (WA) by about 29% and promoted mechanical gains of up to 33% in modulus of elasticity (MOE), 31% in modulus of rupture (MOR), and 133% in internal bond strength (IB). Increasing epoxy from 5% to 10% further enhanced performance, with reductions of 46.3% in TS and 49% in WA after 24 h, and increments of 57.1% in MOR, 68% in MOE, and 104.3% in IB. Scanning electron microscopy confirmed improved encapsulation of wood and PET particles with 10% adhesive. These findings point to a viable circular-economy route by upcycling plastic waste and wood residues into higher-value particleboards while avoiding added formaldehyde.

Current carbon footprint tools for the pulp and paper industry focus on conventional wood fibers and overlook alternative biomass and soil organic carbon (SOC) sequestration. This study developed a software tool for market pulp production comparing conventional eucalyptus and Northern Bleached Softwood Kraft (NBSK) against alternative non-wood fibers (bamboo, switchgrass, sorghum, rice husk, hemp hurd, sugarcane bagasse, wheat straw, rice straw, banana fiber, and ryegrass straw). The tool models kraft and alkaline peroxide mechanical pulping (APMP), integrates ISO 14040-44 standards, and incorporates SOC sequestration based on cultivar morphology. While applicable to diverse market pulps, tissue production is the primary application. Results identify Brazilian Eucalyptus Kraft (BEK) as the most environmentally favorable option. Specifically, the kraft process delivers lower carbon footprints (504 to 794 kg CO₂eq/ADt) than APMP (1,015 to 1,320 kg CO₂eq/ADt) because lignin combustion provides superior energy self-sufficiency. Energy sources critically affect APMP, with wheat straw ranging from 643 to 1,715 kg CO₂eq/ADt (hydropower versus coal), while NBSK varied minimally (631 to 779 kg CO₂eq/ADt). Across the twelve biomasses, high SOC stabilization factors reduced carbon footprints by up to 86%, while low factors showed less than 1% variation. This tool provides a practical platform for industry decision-making and sustainability education.

The aging of paper significantly impacts fiber-water interactions, leading to a decline in dispersibility over time. This deterioration is particularly critical for water-dispersible paper and packaging applications designed to dissolve easily after use, as well as for recycling processes, where reduced dispersibility increases energy consumption and reject content. The aging process is notably faster and more pronounced in unbleached fibers compared to bleached fibers, indicating that lignin plays a crucial role in this phenomenon. A decrease in dispersibility is closely linked to reductions in water retention value (WRV) and increases in paper wet strength, driven by natural aging mechanisms such as hornification, auto-crosslinking, extractives self-sizing, and cellulose recrystallization. These processes reduce fiber swelling capacity and hinder paper disintegration in water. To mitigate the decline in dispersibility due to aging, minimizing moisture cycling and avoiding high temperatures are promising. Also reduction of refining energy and wet-end starch dosage in papermaking are ways to better preserve repulpability. Understanding these aging mechanisms is essential for optimizing paper formulations and ensuring long-term performance in both functional and recyclable paper products.

Lignin, as the most abundant renewable aromatic polymer on earth, holds immense potential as a feedstock for value-added products. However, its recalcitrant and heterogeneous structure presents significant challenges to efficient valorization. While microbial and enzymatic bioconversion offers a sustainable and specific route for lignin depolymerization, industrial implementation is often hindered by limitations such as low enzymatic efficiency, poor operational stability, and restricted substrate accessibility. This review systematically summarizes the current state of lignin bioconversion, focusing on the capabilities of various fungi and bacteria and the ligninolytic enzymes they produce, notably laccases and peroxidases. A key emphasis is placed on the emerging roles of “green” solvents, specifically ionic liquids (ILs) and deep eutectic solvents (DESs), in overcoming these limitations. These solvents not only enhance lignin solubility but also can activate and stabilize ligninolytic enzymes, thereby enabling more efficient depolymerization reactions. This review examines the mechanisms, advantages, and current challenges of integrating ILs and DESs into biomass lignin upgrading strategies. Finally, it discusses future research directions and potential application prospects.

Due to the societal appeal in carbon emission reduction and neutralization, chemical recycling of waste polyester for valuable chemicals has attracted attention in an increasing number of applications. Research on chemical recycling of polyester wastes is currently rising sharply and becoming a hot spot gradually. Many technical and fundamental questions still need to be addressed, such as harsh depolymerization conditions (high temperature, long reaction time, low yields, etc.) and techno-economy and environmental sustainability matters. The chemical recycling protocol and optimization of degradable polyester wastes are systemically investigated along with short discussions on non-degradable ones. The thermoset polyurethane and epoxy adhesives derived from depolymerized waste polyesters for contributing to wood-based structural composite materials (e.g., laminated plywood, fire retarded wood coating, and transparent wood composites) along with life-cycle assessment and techno-economic analysis are also critically evaluated and analyzed. These novel insights are expect to open a new avenue to develop wood-based structural materials via value-added chemicals from polyester waste recycling, which contribute to the sustainable society along with prompting further research and extension in forestry biomaterials and renewable natural resources.

Graphical Abstract

Chitin is the second most abundant natural polysaccharide after cellulose and consists of N-acetyl-D-glucosamine units linked by β-1,4-glycosidic bonds. In nature, chitin does not accumulate due to the synergistic action of chitinolytic enzymes. Based on their catalytic domains, chitinases are classified into glycosyl hydrolase families GH18 and GH19. They are widely produced by bacteria and filamentous fungi. Different types of chitinolytic enzymes, including endochitinases, exo-acting enzymes, and N-acetylglucosaminidases, have been reported to exhibit antimicrobial and insecticidal activities, making them valuable tools for controlling phytopathogenic fungi and insect pests. Chitin degradation generates chitooligosaccharides (COS), which possess diverse biological properties such as antimicrobial, antioxidant, anti-inflammatory, and antitumor activities, contributing to improved human health. Microbial chitinases are also applied in several industrial and environmental processes, including protoplast formation, single-cell protein production, and dye removal. Advances in recombinant expression and genetic engineering have enhanced chitinase production, stability, and catalytic efficiency. Moreover, recombinant chitinases have been successfully utilized in biocontrol strategies and in developing transgenic plants with increased resistance to phytopathogens. This review highlights the broad agricultural, industrial, and biomedical applications of chitinases and their crucial role in promoting environmental sustainability and advancing bio-based industrial processes.

Biofilm-associated infections are a major medical problem that is responsible for nearly 80% of human microbial infections. These bacterial communities are protected by a strong extracellular matrix that limits antibiotic penetration and supports persister cells and quorum-sensing–driven resistance. Biofilm development occurs in several stages and ultimately forms complex structures that block antimicrobial action. To overcome this, chemical strategies include quorum-sensing inhibitors, matrix-degrading agents, antimicrobial peptides, and photodynamic therapy. Biological approaches use bacteriophages, enzymes such as DNase, and probiotics that disrupt biofilms through competitive mechanisms. Combination therapies—such as antibiotic-phage or enzyme-antibiotic treatments—show improved effectiveness. Advanced delivery systems involving nanoparticles, liposomes, and hydrogels enhance drug penetration in biofilms, particularly in wound care. New technologies, including AI-guided drug discovery and CRISPR targeting, are advancing future anti-biofilm treatments.

Biomass densification and molding technology can compress and densify crushed materials into portable solid fuels with a certain shape and density. Such densification has the advantages of high combustion efficiency, high calorific value, environmental protection, and cleanliness. In recent years, scholars have used the finite element method and discrete element method to simulate biomass densification and molding technology, revealing the flow and deformation laws of materials in the biomass densification and molding process from different perspectives. This work has provided reference and guidance for the optimization of biomass densification and molding mechanism and molding dies. This article first reviews the basic ideas of finite element method, as well as the application of ANSYS and ABAQUS in biomass densification and molding technology. Secondly, it reviews the basic ideas of discrete element method and the application of EDEM and PFC in biomass densification and molding technology. Finally, it reviews the application of combined finite element method with discrete element method in biomass densification and molding technology. The content of the article has certain reference and guidance significance for the numerical simulation of future biomass densification and molding technology.

This paper presents a systematic review of the academic literature published until 2024 about sustainability and the furniture industry. Relevant publications were selected through keyword searches in Scopus and the Web of Science databases. One hundred and one publications were identified after having removed duplicates and other, non-peer-reviewed papers. A content analysis on the 101 identified publications allowed the classification of these papers into the following categories: “Sustainable Design” (21%), “Supply Chain Management” (14%), “Sustainability Strategies” (10%), and “Environmental Management” (9%) with the remaining publications (46%) being distributed among eleven other categories. To find out if the topic attracts more interest today than 10 or 20 years ago, the study also analyzed the distribution of publications by year. Investigations were also done by type of publications, countries, and focal points. Findings suggest that academic studies on sustainability in the furniture industry are still scattered and no coherent or continuous research stream has yet evolved. However, interest in the topic has been increasing lately.