Volume 21 Issue 3

To develop a green, efficient, fluorine-free waterproof pulp molding material, this study incorporated chitosan-stearic acid graft copolymer (CS-SA) into the pulp fiber system via the conventional internal pulp addition method used in the papermaking industry. Compared with post-treatment surface techniques such as spraying and coating, adding the waterproofing agent directly into the pulp ensures its uniform distribution throughout the three-dimensional fiber network—from the pulp to the final product—while balancing the operational feasibility of paper manufacturing with the integrated waterproofing performance of the finished product. The research results demonstrated that CS-SA significantly enhanced the waterproof performance of the product (water contact angle 131°, Cobb value 12.9 g/m², no leakage or permeation at 100 °C water for 30 minutes). Systematic characterization revealed that CS-SA forms a dense hydrophobic film on the fiber surface and between fibers, which is the key to its high-efficiency waterproofing. In addition, the modified material exhibits low cytotoxicity and excellent antibacterial properties, ensuring safety for applications in food packaging. Its superior thermal stability guarantees effectiveness during processing steps such as pulp molding and hot pressing.

Increases in temperature, rainfall, and sea level associated with climate change have intensified flooding and saltwater intrusion, thereby posing a growing threat to oil palm cultivation. To evaluate the effects of these environmental stressors, 12-month-old oil palm seedlings were subjected to control, flooding, salinity, and combined flooding and salinity treatments. Physiological and biochemical parameters were measured, including total chlorophyll, antioxidant enzyme activities, lipid peroxidation, and proline content. Phytochemical profiles, such as total phenolics, flavonoids, alkaloids, terpenoids, and antioxidant activity, were also assessed. Combined stress caused the most severe reductions in chlorophyll and phytochemicals, with increased lipid peroxidation and visible symptoms such as leaf yellowing and adventitious root formation. Proline accumulation was markedly higher under combined stress, suggesting a protective role. In contrast, individual stress treatments induced antioxidant enzyme activity, contributing to reactive oxygen species mitigation. These findings highlight the distinct and synergistic impacts of flooding and salinity on oil palm seedling health. The results offer a foundation for identifying stress-resilient traits, which can support future breeding or management strategies to sustain oil palm productivity under changing climate conditions.

Wood pellets, which are regarded as a sustainable and nature-friendly energy source, occupy an important place in biomass production, and global pellet production is constantly increasing. Pellet quality varies significantly according to the structural properties of the wood used as raw material, and the wood structure is the most important factor that determines the quality of the pellet. Numerous studies have been conducted on the quality of pellets produced from various raw materials. Although different origins of the same species can significantly affect pellet quality, the study on this subject is very limited. C, O, N and H contents, pH and heavy metal contents of pellets produced from Fagus orientalis wood obtained from 12 different origins were compared. As a result of the study, it was determined that there was a statistically significant difference between the pellets produced from wood obtained from different origins in terms of Cd and Ni concentrations, as well as oxygen, nitrogen, and hydrogen contents. The results indicate that the highest quality pellets among the origins studied were those produced from beeches from the Andırın, Yazıcık, Gökçebey, and Kalkım origins, which had both low heavy metal content and low oxygen, nitrogen, and hydrogen contents. It is proposed that these origins be given priority in pellet production.

The global transition toward environmentally sustainable technologies necessitates the development of biodegradable electrical insulating fluids. This study investigates the performance of a vacuum–fractional distillation reactor designed to convert high free fatty acid (FFA) crude palm oil (CPO) into a biodegradable electrical insulator. The reactor simultaneously performs degumming, deodorization, and vacuum spray drying, thereby enabling efficient purification and moisture removal. Experimental results demonstrated that even at a minimal processing time of 20 min, the breakdown voltage (BDV) exceeded 50 kV with the IEC 60156 (2018) test, with a peak performance of 59 kV at 50 min. The reactor achieved Specific Energy Consumption of 2.1 kWh/L. Thermal analysis indicated that 0.136 kWh was converted into useful heat, resulting in a thermal efficiency of approximately only 4.3%, primarily due to heat losses and irreversibility associated with the uninsulated laboratory-scale configuration, thereby indicating potential for improved heat utilization and energy recovery. The novelty of this work lies in the process integration, enabling treatment of high-FFA CPO in a single system, reducing operational complexity, and enables energy analysis. However, while the breakdown voltage requirement was satisfied, full compliance with IEC 62770 specifications necessitates further physicochemical characterization, which will be explored in future work.

In plants, the transport of water is mediated by vessel and pit structures, which are integral to this physiological process. Among the various pit types, the bordered pit is recognized as particularly effective. To investigate the impact of structural parameters on fluid flow performance, a microstructural fluid dynamics model of plant tissue was developed employing finite element simulation. This model integrates laminar flow and porous media physics within a unified framework, and the computed results agreed with existing experimental and numerical studies. An analysis was conducted to assess variations in pressure drop, flow rate, and flow resistance as a function of several parameters, including pit aperture diameter, torus diameter, pit diameter, pit depth, margo thickness, porosity, and micropore diameter. The results demonstrate that overall flow resistance decreases with increases in pit diameter, pit aperture diameter, pit depth, porosity, and micropore diameter, whereas it increases with larger torus diameter and margo thickness. Notably, parameters associated with the margo exert a particularly pronounced effect on water transport characteristics. This study provides a mechanical rationale elucidating the structure-function relationship governing water transport in coniferous plants and offers theoretical foundations for the design of biomimetic microfluidic devices and plant-inspired water-conducting materials.

The impact of drought and Pb toxicity were evaluated relative to physiological and biochemical traits of four commonly used urban tree species. The experiment included six treatments: control, 300 ppm Pb, 600 ppm Pb, drought (50% field capacity), drought + 300 ppm Pb, and drought + 600 ppm Pb, applied to Platanus orientalis, Fraxinus excelsior, Cupressus sempervirens, and Pinus nigra. Results showed that Pb toxicity – particularly 600 ppm and drought – led to changes in most traits of the plants (P ≤ 0.05). The co-applied drought and 600 ppm Pb decreased total chlorophyll (Chl, 21%), relative water content (RWC, 23%), while increased malondialdehyde (MDA, 52%), proline accumulation (22%), total soluble sugar (TSS, 54%), superoxide dismutase (SOD, 110%), catalase activity (CAT, 137%), Pb accumulation in roots (1723%), and in shoots (611%) compared to the control. Compared to C. sempervirens and P. nigra, P. orientalis and F. excelsior accumulated more Pb and exhibited greater sensitivity to abiotic stress. The heat map results exhibited that traits under drought and Pb stress showed the most significant fluctuation, with TSS explaining the most variation among measured traits.

Hydrogels based on TEMPO-oxidized cellulose nanofibrils (TOCNF) are attractive sustainable materials but often suffer from poor structural stability and weak mechanical strength. In this study, surface-deacetylated chitin nanofibrils (ChNF) were incorporated to reinforce TOCNF hydrogels, and the effect of hydrothermal treatment on network structure and properties was investigated. Hydrogels were prepared at solid contents of 1.25 to 2.00 wt% by mixing dilute TOCNF and ChNF suspensions followed by centrifugation and hydrothermal treatment. Compared with TOCNF alone, TOCNF/ChNF hydrogels exhibited improved shape stability, higher viscosity, and enhanced shear-thinning behavior. Hydrothermally treated TOCNF/ChNF hydrogels maintained elastic behavior up to 74.6% strain, compared with 26.3% strain for non-treated TOCNF/ChNF hydrogels. The compressive strength increased markedly, reaching 36 kPa at 1.75 wt%, whereas TOCNF hydrogels showed only ~5 kPa. FTIR and XPS analyses indicated redistribution of intermolecular interactions after hydrothermal treatment without definitive evidence of covalent bond formation. SEM observations further revealed the formation of a more interconnected and densified porous network after hydrothermal treatment. Overall, ChNF reinforcement combined with hydrothermal treatment effectively improved the structural stability and mechanical performance of TOCNF hydrogels.

This study investigated the potential of dry processing methods to manufacture bio-based materials with reduced environmental impacts, which is in alignment with the energetic and ecological transitions global strategies. The increasing demand for eco-friendly materials drives research into bio-based composites. The mechanical properties were evaluated for binderless composites made from walnut shells, which are industrial bio-based by-products. Thermocompression moulding was used to fabricate the composites. Their mechanical behaviour and their resistance to water were tested. The composites showed a flexural strength of 16.9 MPa and a Young’s modulus of 4.3 GPa. These findings suggest that walnut shell-based composites are viable alternatives for sustainable materials.

Lignocellulosic biomass is a widely available renewable resource, yet its recalcitrant structure limits enzymatic hydrolysis and bioethanol production. This study aimed to develop an efficient pretreatment method for pine wood chips by integrating steam explosion with potassium hydroxide (KOH) treatment and to explore the reuse potential of the resulting liquid waste. Steam explosion disrupted chip structure and exposed cellulose, while subsequent KOH pretreatment selectively removed lignin and hemicellulose, thereby enhancing enzymatic accessibility. Response surface methodology identified optimal conditions of 2.9 min steam explosion, 1.4% KOH, and 21 h treatment time, which yielded a maximum glucose conversion of 30% (based on raw material). The combined process increased ethanol production, with yields approximately sevenfold higher than untreated controls. In addition, liquid waste containing potassium elements promoted the growth of red lettuce, perilla, and green onion, with perilla showing a fivefold increase in fresh weight compared to controls. These findings demonstrate that steam explosion coupled with KOH pretreatment not only improves the efficiency of bioethanol production but also offers a sustainable route for recycling liquid residues as agricultural fertilizer.

N,P co-doped porous carbon (NPPC) was prepared as a high-performance electrode material for supercapacitors. NPPC materials were synthesized through a facile single-batch carbonization-activation strategy. Poria cocos residue was used as a renewable biomass precursor, potassium carbonate as the chemical activator, and melamine phosphate served as the dual N/P doping agent. A Box-Behnken design  in response surface methodology was utilized to optimize three critical process parameters: K₂CO₃ ratio, N,P co-doped ratio, and activation temperature, aiming at maximizing the specific capacitance. The morphological, structural, and electrochemical properties of the prepared carbon materials were systematically characterized by scanning electron microscopy, N₂ adsorption–desorption  isotherms, X-ray photoelectron spectroscopy, cyclic voltammetry, galvanostatic charge-discharge technique, and electrochemical impedance spectroscopy. The optimized NPPC exhibited hierarchical porous structure with a high specific surface area (reaching 2980 m²⋅g⁻¹), uniformly distributed N (12.3 at.%) and P (0.59 at.%) heteroatoms, and excellent supercapacitive performance. It achieved a maximum specific capacitance of 332 F⋅g⁻¹ at a current density of 1 A⋅g⁻¹ in a 6 M KOH electrolyte. This work realizes the high-value valorization of TCM solid waste and provides a green, cost-effective, and scalable route for the synthesis of high-performance supercapacitor electrode materials, aligning with the goals of waste recycling and carbon neutrality.