Polyaniline (PANI) electrode materials exhibit low capacitance and poor stability due to self-shrinkage and agglomeration in practical applications. In this work, PANI was grown in situ on the ...framework of the liquefied wood carbon aerogel (LWCA) skeleton by chemical oxidation polymerization to improve the self-agglutination problem of PANI, obtaining the composite electrode material (LWCA-PANI) for hybrid supercapacitors. As expected, Three-dimensional structure of LWCA could effectively hinder the aggregation of polyaniline nanofibers, significantly expanding the accessible area of ions and alleviating volume expansion by preventing stacking to improve capacitive performance. The optimized LWCA-PANI3 electrode material exhibited a remarkable specific capacitance of 507.55 F g−1 at a current density of 0.5 A g−1, and demonstrated excellent cycle stability with a retention rate of 75.37% after 4000 cycles. Furthermore, the supercapacitor assembled by LWCA-PANI3 demonstrated a largest energy density of 32.08 W h kg−1 at 400 W kg−1 power density and an admirable cycling durability of 76.12% retention for up to 4000 cycles. Consequently, LWCA-PANI3 composites showed a broad application prospect in electrode materials for hybrid supercapacitors.
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•Polyaniline (PANI) was successfully grown on liquefied wood carbon aerogel (LWCA).•LWCA prevented PANI agglomeration to improve the electrochemical performance.•LWCA-PANI symmetric supercapacitor’s energy density was 32.08 W h kg−1.•LWCA-PANI electrodes had high specific capacitance and good cycle stability.
In order to investigate the effect of boron element on liquefied wood carbon fibers and their composites, boric acid and boron carbide were utilized to modify liquefied wood resin through ...copolymerization and blending methods respectively. Then boric acid-modified liquefied wood carbon fiber (BA-WCF) and boron carbide-modified liquefied wood carbon fiber (BC-WCF) were produced via melt spinning, curing, and carbonization treatments. As expected, this modification approach effectively prevents the formation of skin-core structures and accelerates the evolution of a graphite microcrystalline structure, thereby enhancing the mechanical properties of the carbon fibers. Particularly, the tensile strength and elongation at break of BA-WCF increased to 331.57 MPa and 7.57 % respectively, representing increments of 117 % and 86 % compared to the conventional fibers. Furthermore, the as-fabricated carbon fiber/resin composites (CFPRs), composing of BA-WCF or BC-WCF as fillers and liquefied wood resin as matrix, exhibited excellent interlaminar shear strength, outstanding abrasion resistance, and well thermal conductivity, as well as electrical performance, significantly outperforming the conventional carbon fiber/phenolic resin composites. The friction rate of BC-WP/BA-WCF/CF was 2.37 %, while its thermal conductivity could reach 1.927 W/(m·K). These promising attributes lay the groundwork for the development of high-performance carbon fiber-based materials, fostering their widespread utilization across various industries.
In this study, wood of Cryptomeria japonica D. Don (Japanese fir) was liquefied with phenol as a solvent. Phenol‐liquefied wood was mixed with formalin and spherical phenol‐formaldehyde resin (PF) ...beads were prepared by a two‐stage suspension polymerization reaction. The influence of the kind and dosage of polyvinyl alcohol (PVA) on the particle size distribution, mechanical strength and thermal properties of spherical PF beads were investigated. The results show that PF beads prepared with partially saponified PVA as a granulating agent are smaller than 75 μm, while the PF beads prepared with fully saponified PVA have larger diameters. However, the average diameter of spherical PF beads decreased with the increase of PVA addition. Thermogravimetric analysis (TGA) indicates that the initial thermal degradation temperature of the PF beads is around 150°C, and the main weight loss occurs between 400 and 600°C. Among them, the PF beads with BF‐04 as the granulating agent have the best heat resistance, and have the highest char yield at 800°C. The Brunauer, Emmett and Teller surface adsorption shows that the internal structure of the carbonized spherical PF beads is microporous pores. Carbonized beads prepared with high PVA adding have large absorption volume.
Spherical phenol‐formaldehyde resin (PF) beads were prepared by a two‐stage suspension polymerization reaction from phenol‐liquefied wood. The average diameter of spherical PF beads decreased with the increase of polyvinyl alcohol (PVA) addition. PF beads with BF‐04 as the granulating agent have the best heat resistance. Carbonized beads prepared with high PVA adding have large absorption volume.
Carbon aerogels (CAs) from biomass have low energy density and specific capacitance due to underutilized structure, severely hindering their application in high-performance supercapacitors. Herein, ...we address this issue through a binary composite in which psudocapacitive polypyrrole (PPy) microparticles are in situ grown on the surfaces of hierarchical porous liquefied wood carbon aerogels (LWCA). The deposited pseudocapacitive PPy microparticles contributes to the high energy density and specific capacitance. The hierarchical structure of LWCA prevents aggregation of PPy microparticles and ensures rapid transfer of electrolyte ions. In three electrodes system, the optimized hybride capacitive LWCA-PPy-65 composite exhibites excellent capacitive performance of 421.45 F g−1 and cycle stability with 82.9% after 5000 cycles. In KOH electrolyte, the hybrid supercapacitor from LWCA-PPy-65 demonstrates a high energy density of 52.0 Wh kg−1 with a power density of 2012.8 W kg−1, and excellent cyclic performance of 92.81% retention after 5000 cycles at 5 A g−1. In H2SO4 electrolyte, the fabricated solid state supercapacitor displays prominent cyclic performance of 92.81% retention after 5000 cycles at 5 A g−1. Such three-dimensional biomass-based composite aerogels with high energy density and capacitance demonstrated a promising application prospect in energy storage devices.
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•Polypyrrole-decorated hierarchical carbon aerogel from liquefied wood is proposed.•The high specific capacitance (∼421.45 F g−1) and capacitive contribution (∼97.2%).•The excellent adaptability and cycle stability under acidic and alkaline electrolyte.•Enhanced power density (2012.8 W kg−1) and energy density (52.0 Wh kg−1).
Ordered mesoporous carbon materials with diverse architectures including flakes, fibers, rods, gyroids, gyroids with nanoparticles, and spheres were successfully prepared from liquefied wood by ...controlling the nucleation and growth process through modulating the concentration of HCl via a facile hydrothermal/soft templating method.
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•Well-defined gyroid-like ordered mesoporous carbon materials were synthesized through a facile hydrothermal/soft templating method.•Biomass derived liquefied wood was used as the carbon precursor.•The morphology of ordered mesoporous carbon materials can be readily designed via the nucleation and growth process by changing the concentration of HCl.
A HCl concentration-controlled hydrothermal/soft-templating strategy is proposed to prepare ordered mesoporous carbons (OMCs) with diverse morphologies from flakes to gyroids then to spheres by using liquefied wood as a carbon precursor. The effect of nucleation and growth process on morphology change was systematically studied. Results showed that an accelerated nucleation rate and a transformation of self-assembly pattern from slow and weak aggregates to fast and strong assembly are achieved in accordance with increasing HCl concentration. Detailed mechanism studies reveal that a reaction solution without seed nuclei formed at the initial stage of the hydrothermal process under low HCl concentration will lead the micelles to slowly self-assemble into microscale flakes, whereas a high HCl concentration will make the micelles rapidly self-assemble into rodlike micelles and further grow along the surface of the initially formed seed nuclei to produce nanoscale products with an annular structure. The OMCs with highly ordered p6mm mesostructure synthesized at a proper HCl concentration of 1.61 M exhibit higher electrochemical performance than the less ordered OMCs. The detailed study of nucleation and growth mechanism provides new understanding of controllable design and synthesis of OMCs with desired morphology.
•Possible reaction paths for the preparation of ACFs from liquefied wood were proposed.•Some incompletely liquefied substances decomposed during carbonization.•Reactions between KOH and carbon began ...at 530°C.•The main gaseous products were H2, H2O, CH4, CO, CO2.
In this study, wood-based fibers were used as raw materials to prepare activated carbon fibers (ACFs) by carbonization at 500°C followed KOH activation at 850°C process. The structure of the fibers was characterized by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analyses. Besides, the volatiles of the final products were determined by thermogravimetry-mass spectrometry (TG-MS) and titration. The reaction mechanisms were consequently deduced. In the first carbonization process, it was mainly related to substitution, scission, and oxidization reactions of methylene. And in the second activation process, KOH and carbon began to react at 530°C, resulting in potassium compounds, which further reacted with carbon. Meanwhile, temperature elevation caused polycyclic reactions, which made the ACFs a graphite-like microcrystalite structure.
Epoxy resin (ER) is one of the most widely used synthetic resins, and the improvement of its toughness is an important issue. In this study, Epon 828 is used as ER resin, polytetramethylene ether ...glycol (PTMG) and liquefied wood (LW) are used as polyol, and IPDI, H12‐MDI, Desmodur N, and Desmodur L are used as isocyanate. The influence of polyurethane resin (PU) composition on the reactivity of ER/polyol/isocyanate blended resin and the properties of ER/PU composite are investigated. The results show that the mixture of ER/PTMG/IPDI has greater reactivity, followed by ER/PTMG/Desmodur N, while ER/PTMG/Desmodur L has lower reactivity. In the structure of ER/PU blended resin composites, ER and PU resins not only form a physical interpenetrating structure, but also undergo a copolymerization crosslinking reaction. The modulus of elasticity of ER/PU composites prepared with trifunctional Desmodur L and Desmodur N is greater than that of bifunctional IPDI and H12‐MDI, while those with LW as polyol is greater than that of PTMG as the raw material.
Different polyols (PTMG and LW) and isocyanate (IPDI, H12‐MDI, Desmodur N, and Desmodur L) are added directly to epoxy resin, the reactivity of epoxy/polyol/isocyanate blended resins and the properties of ER/PU composites are investigated. The results show that the ER resin and the PU not only form a physical interpenetrating structure, but also undergo a copolymerization crosslinking reaction.
The objective of this study was to enhance the properties of water-borne acrylic coatings by modifying them with biopolymers. Water-borne coatings are more and more commonly used in the wood and ...furniture industry. To improve the performance of these coatings, there is a need to apply reinforcing agents. Among these, besides the well-studied inorganic nanoparticles, biopolymers are gaining increasing attention. In this study, a base acrylic coating material was filled with biopolymers having a wide variety of properties and functionalities, including nanocrystalline cellulose and two types of liquefied wood, in amounts of 1.0%, 3.0% and 5.0% by dry weight of coating. Two wood species, pine and beech, were selected for coating. Properties of the coatings were determined in order to assess the quality of the new coating formulations. Bearing in mind that the main cause of coating failure during interior exposure is mechanical defects, impact and abrasion resistance tests were performed. The abrasion resistance of the coatings was found to be increased by nanocrystalline cellulose and liquefied wood, most significantly at 1% loading. The results also indicated improvement in the impact resistance of coatings filled with nanocrystalline cellulose.
•Biopolymers were applied to enhance the properties of water-borne acrylic coatings•Coatings filled with nanocrystalline cellulose showed higher impact resistance•Abrasion resistance was increased using nanocrystalline cellulose and liquefied wood, most significantly at 1% loading•Liquefied wood and nanocrystalline cellulose act as a fillers and matting agents
The architectures of carbon materials prepared via soft‐templating method greatly depend on the assembly pattern of micelles. Herein, a kinetics‐controlled strategy is developed to fabricate ordered ...mesoporous carbon (OMC) single crystals from liquefied wood by using melamine to regulate the polymerization rate of carbon precursors, which further affects the assembly process. Due to the slow hydroxymethylation reaction of melamine with formaldehyde in acid, the addition of melamine can decelerate the reaction kinetics to produce no seed nuclei at the initial stage, which favors the composite micelles to orderly aggregate and further grow in a layer‐by‐layer pattern to form OMC single crystals after carbonization. The OMC single crystals with high specific surface areas (733 m2 g−1), uniform mesopore size (3.2 nm), and ordered Im3m mesostructure are ideal supports to couple with Ag nanoparticles to act as efficient catalysts, which exhibits remarkable catalytic performance for the reduction of 4‐nitrophenol.
A kinetics‐controlled strategy is developed to synthesize ordered mesoporous carbon single crystals from liquefied wood. The slow hydroxymethylation process of melamine in acid can decelerate the reaction kinetics thus no seed nuclei are formed at the initial stage, which favors the composite micelles to orderly assemble and further act as nuclei for other micelles to pack in a layer‐by‐layer pattern.
