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An architected silk fibroin-lignin multilayer with deep-level trapping states for high-output triboelectric nanogenerators
(2026-03-01)
Suktep, Natdanai
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Sae-tang, Chanachot
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Ukasi, Sirinya
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Pakawanit, Phakkhananan
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Supansomboon, Supitcha
Biopolymer-based triboelectric nanogenerators (B-TENGs) are promising power sources for sustainable and flexible electronics, but their performance is often limited by severe charge recombination at the triboelectric interface. To overcome this critical bottleneck, we report an architected multilayer B-TENG featuring a silk fibroin (SF)/MgAl LDH composite as the charge-generating layer and, to our knowledge, for the first time, a lignin-functionalized SF film as a dedicated charge-trapping layer. The strategic incorporation of lignin, an abundant and sustainable biopolymer, introduces deep-level electronic trapping states originating from its abundant aromatic moieties. That effectively suppresses interfacial charge recombination and prolongs charge lifetime. By optimizing the contents of MgAl LDH and lignin, the device achieves a measured open circuit output voltage ( V <inf> OC </inf>) and current density ( J <inf> SC </inf>) of 96 V and 6.56 μA/cm3, with a maximum output power ( P <inf> max </inf>) of 205 μW, corresponding to a power density of 22.7 μW/cm2. We also propose a mechanistic linking of deep-level traps to prolonged charge lifetime and increased net transferable charge. The interface-engineering strategy demonstrated here paves the way for developing high-performance and sustainable biopolymer-based TENGs and motion sensors.
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Dynamic changes in cellulose content and biomechanical properties of mycorrhizal roots during growth and decay
(2023-09-01)
Kamchoom, Viroon
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Chen, Xun Wen
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Leung, Anthony Kwan
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Sakolpanya, Tapakorn
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Srinil, Chortham
Aims: Arbuscular mycorrhizal (AM) fungi have been found to increase plant biomass, cellulose content, and the associated root biomechanical properties, but little is known about how AM fungi affect the in situ root decay process in terms of the changes in the chemical and biomechanical properties. Methods: In this study, we inoculated AM fungi to Bermuda grass (Cynodon dactylon L.) and measured the biomass, the contents of cellulose and lignin, and the biomechanical properties, including tensile strength and Young’s modulus of the grass roots as they grew for 180 days and then decayed for 360 days after burning or for 60 days after the herbicide application. Results: Results show that the AM fungi accelerated the accumulation of grass biomass and root cellulose content compared with non-mycorrhizal grass during the growth period. This effect of AM fungi made mycorrhizal grass generally maintained more biomass and cellulose content than non-mycorrhizal grass at every decaying stage. Inoculation of the AM fungi did not significantly change the root tensile strength or Young’s modulus, but it altered the correlations between tensile strength and root diameter, and Young’s modulus and root diameter. Mycorrhizal effects during the root decaying process appeared to diminish under herbicide treatment, compared with normal growth and burning treatments. Conclusion: Our study highlights the important role of AM fungi in maintaining in situ root biomass (a proxy for carbon content) from decaying or decomposing.
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Optimization of Vanillin Production from Lignin Using Catalytic Depolymerization over a CuO/Al2O3 Catalyst
(2023-01-01)
Sangnak, Sirawit
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Neramittagapong, Arthit
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Neramittagapong, Sutasinee
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Theerakulpisut, Somnuk
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Sriprom, Pongsert
The optimal conditions for vanillin production from lignin depolymerization using CuO/Al2O3 catalysts were determined by combining Box-Behnken design (BBD) and response surface methodology (RSM). Independent variables, including temperature (80–140 °C), NaOH loading (0.5–1.5 g), time (30–90 min), and catalyst weight (0.5–1.5 g), were investigated to determine the optimal conditions, with the concentration of vanillin being the dependent variable. A CuO/Al2O3 catalyst was prepared by impregnation method. The vanillin obtained from the reaction was analyzed using high-performance liquid chromatography (HPLC). The maximum obtained vanillin concentration of 59.14 mg·L-1 was achieved with a temperature of 80 °C, a reaction time of 90 min, NaOH loading of 1.5 g, and 1.5 g of catalyst. The amount of NaOH was the most influential factor governing the obtained vanillin concentration. Regression analysis was performed to determine the formula describing the vanillin concentration in terms of the independent variables with a reasonable degree of accuracy (R2 = 0.87). This study shows that the optimal conditions for the depolymerization of lignin to vanillin over a CuO/Al2O3 catalyst can be achieved under milder conditions than those reported previously.
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Treatment of Lignin Wastewater Using Peroxydisulfate Combined with Manganese Oxide-Loaded Biochar
(2022-09-01)
Suwannarat, Glinsukol
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Sontabam, Kemason
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Sawangying, Soraya
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Chaiyaraksa, Chompoonut
The pulp and paper industry wastewater discharge into public water, it will cause water pollution problems. In this research, lignin contaminated synthetic wastewater with a COD value of 2,401 mg/L, and color intensity of 5,432 ADMI was treated using 150 mM sodium peroxydisulfate in combination with MnO<inf>x</inf>-loaded biochar (MnO<inf>x</inf>-B). The MnO<inf>x</inf>-B was produced by pyrolyzing corn core at 400 °C for 4 hours without oxygen, then dipped in 40 mM manganese sulfate for 2 hours, and heated at 600°C for 30 min without oxygen. From the characterization of MnO<inf>x</inf>-B, the surface area, pore volume, pore size, and pH value at the zero-point charges of MnO<inf>x</inf>-B were 153 m2/g, 0.054 cm3/g, 1.11 nm, and 7.23, respectively. From the FTIR spectrogram, the peak assigned to Mn-O was observed. By applying 150 mM sodium peroxydisulfate and varying three parameters: MnO<inf>x</inf>-B dosage, initial wastewater pH, and reaction time, to treat lignin wastewater, the optimum experimental condition was obtained using 2 mg/L of MnO<inf>x</inf>-B, under pH of 8 for 45 min. The COD and color removal efficiencies were 73% and 90%, respectively. However, the quality of the treated wastewater did not yet pass the pulp and paper mills effluent standards of the Department of Industrial Works.
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Biomechanical properties of the growing and decaying roots of Cynodon dactylon
(2022-02-01)
Kamchoom, Viroon
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Boldrin, David
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Leung, Anthony Kwan
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Sookkrajang, Chanakan
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Likitlersuang, Suched
Aim: Root growth and decay may affect root reinforcement to soil erosion and stability. We measured the effects of growth and decay on the tensile strength of Cynodon dactylon roots considering different causes of mortality common to agricultural land conversion (i.e. burning and herbicide application). Method: We applied three treatments to C. dactylon grass: (i) growth duration (60, 120 and 180 days), (ii) decay duration after burning (30, 60, 120, 180 and 360 days) and (iii) decay duration after herbicide application (15, 30 and 60 days). The diameter, tensile strength and cellulose and lignin contents of root samples (n = 303) in different treatments were measured. Results: Tensile strength–diameter relations followed a negative power law regardless of treatment (R2 > 0.6). The increase in median tensile strength values due to grass growth was consistent with the increase in cellulose and lignin contents. Root decay by herbicide application caused significantly greater and faster reduction in tensile strength than burning treatment because of the faster reduction of cellulose and lignin contents. Conclusion: Root decay due to different causes of plant mortality can increase susceptibility to erosion and slope instability during the conversion of agricultural land. Measures on slope safety and erosion are vital when using herbicides for weed clearance in farmlands due to the faster deterioration of root chemical composition and root tensile strength (compared with burning).
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Optimization of lignin conversion to phenol via partial oxidation of synthesized wastewater containing lignin
(2020-12-01)
Sriprom, Pongsert
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Leephisuth, Pornyamon
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Assawasaengrat, Pornsawan
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Neramittagapong, Arthit
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Neramittagapong, Sutasinee
This work was to optimize operating parameters for phenol production via partial oxidation. The essential settings, NaOH loading of 4–20 g/L, reaction temperatures of 140–180 °C, and time of 15–45 min, were set as the independent parameters for designing the experiments. A set of tests was generated using Box–Behnken Design (BBD) and performed in a high-pressure reactor at the constant air pressure of 2 bars. A produced phenol concentration was assigned as a response target for evaluating an optimal condition. From the results, a quadratic model of actual data was fit with high accuracy (R2 of 94.1%). A response surface methodology (RSM) was used to evaluate the operating parameters effect on the phenol formation. It showed that the temperature rising affected phenol formation due to the creation of aldehydes at low temperatures and phenol re-polymerization. The presence of NaOH plays an essential role in the production of phenol. It may increase the hydroxyl group's rate to an aromatic ring that yields a high percentage of phenol production. For the reaction time, the longer time gave a higher yield of phenol. However, it slightly increased after 30 min. The predicted optimal condition was determined at the temperature of 161 °C, the NaOH loading of 16.4 mg/L, and the reaction time of 36.2 min. Three experiments were performed at the optimal point to verify the prediction. It was found that the phenol concentration of 30 ± 1 mg/L was yielded at this condition. Moreover, the reaction temperature and the initial pressure of air were not severe. It indicates that the partial oxidation of aqueous lignin solution can produce phenol at mild conditions.

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