Carbon Formation Research Articles

Interfacial strength and its regulation in the carbon monofiber/epoxy binder system

The strength of polymer composite materials (CMs) is largely determined by the strength of interfacial interactions at a fiber/matrix interface. In this work the strength in a unit cell of CM carbon monofiber/cured epoxy matrix is investigated. The relevance of the work is due to direct measurements of strength at the monofiber/matrix interface, excluding defects of micro-droplet and technological errors associated with impregnation in a traditional assessment of polymer composite materials strength. Changes of surface morphology and energy characteristics of fibers in plasma chemical treatment process is shown. The study of fiber surface energy and formation of carbon monofiber/epoxy matrix interface of carbon fiber reinforced composite unit cell was carried out on the specially developed original device Drop-Sting test. Micro pull-out test was used to investigate the shear mechanical properties of interface and to determine the strength of carbon fiber reinforced composite unit cells before and after treatment in oxygen discharge plasma. It is shown that the increase in the strength of the monofiber/matrix interfacial interface after the treatment of carbon fiber in plasma occurs due to the increase in the surface energy and wettability of monofibers.

A Hydrochemical Method for Identifying Orbital Imprints of Dust in Paleofluvial Sequences

AbstractMineral dust plays an important role in Earth's climate system, yet it is difficult to identify dust imprints in paleofluvial sediments, especially on orbital timescales. Here, we present high‐resolution authigenic carbonate Ca–Mg–Sr compositions in a fluvial sequence under the transport pathway of Asian dust. The Mg/Ca, Sr/Ca, and Mg/Sr ratios exhibit distinct transitions in both secular trends and orbital cycles at ∼8 Ma. Before ∼8 Ma, given similar Mg and Sr partitioning behaviors during carbonate formation, hydroclimate changes yielded strong orbital signals in the Sr/Ca and Mg/Ca ratios but no detectable signals in the Mg/Sr ratios. After ∼8 Ma, given the strengthened input of Mg‐rich dust during cold‒dry periods, the Mg/Sr and Mg/Ca ratios clearly exhibited orbital signals, but the Sr/Ca ratio did not. Such transitions in carbonate composition corroborate the dust‐induced changes in fluvial hydrochemistry, offering an innovative methodology for detecting orbital dust cycles in paleofluvial systems.

Reactive CaCO3 Formation from CO2 and Methanolic Ca(OH)2 Dispersions: Transient Methoxide Salts, Carbonate Esters and Sol-Gels.

A combination of ex situ and in situ characterization techniques was used to determine the mechanism of calcium carbonate (CaCO3) formation from calcium hydroxide (Ca(OH)2) dispersions in methanol/water (CH3OH/H2O) systems. Mid-infrared (mid-IR) analysis shows that in the absence of carbon dioxide (CO2) Ca(OH)2 establishes a reaction equilibrium with CH3OH, forming calcium hydroxide methoxide (Ca(OH)(OCH3)) and calcium methoxide (Ca(OCH3)2). Combined ex situ mid-IR, thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray absorption spectroscopy and scanning electron microscopy examination of the reaction product formed in the presence of CO2 reveals the formation of calcium dimethylcarbonate (Ca(OCOOCH3)2). This strongly suggests that carbonation takes place by reaction with the Ca(OCH3)2 formed from a Ca(OH)2 and CH3OH reaction. Time-resolved XRD indicates that in the presence of H2O the Ca(OCOOCH3)2 ester releases CH3OH and CO2, forming ACC, which subsequently transforms into vaterite and then calcite. TGA reveals that thermal decomposition of Ca(OCOOCH3)2 in the absence of H2O mainly leads to the reformation of Ca(OCH3)2, but this is accompanied by a significant parallel reaction that releases dimethylether (CH3OCH3) and CO2. CaCO3 is the final product in both decomposition pathways. For CH3OH/H2O mixtures containing more than 50 mol % H2O, direct formation of calcite from Ca(OH)2 becomes the dominant pathway, although the formation of some Ca(OCOOCH3)2 was still evident in the in situ mid-IR spectra of 20 and 40 mol % CH3OH systems. In the presence of ≤20 mol % H2O, hydrolysis of the ester led to the formation of an ACC sol-gel. In both the 90 and 100 mol % CH3OH systems, diffusion-limited ACC → vaterite → calcite transformations were observed. Traces of aragonite were also detected. We believe that this is the first time that these reaction pathways during the carbonation of Ca(OH)2 in a methanolic phase have been systematically and experimentally characterized.

Optimization of Cu/MnO2 catalyst for enhanced methane bi-reforming: a response surface methodology approach for sustainable syngas production

Hydrogen or syngas, valued for its clean and high-energy properties, stands as a promising solution to future energy shortages by converting CO2 and CH4 waste into renewable syngas through a reaction known as methane bi-reforming. Hence, the purpose of this current research is to examine the effectiveness of Cu/MnO2 catalyst in methane bi-reforming (MBR) using response surface methodology (RSM). The synthesis of the 15%Cu/MnO2 catalyst was accomplished using the ultrasonic impregnation method, followed by a comprehensive analysis and characterization of the catalyst using CO2-TPD, BET, H2-TPR, TPO, and XRD evaluation. The effect of reaction parameters was investigated using RSM analysis, including temperature, CO2/CH4 ratio, and gas hourly space velocity (GHSV) (700–900 °C, 0.2–1.0, and 16–36 L g cat−1 h−1, respectively). According to the analysis of variance and three-dimensional response surface plots, it was determined that CH4 conversion and H2 yield were largely influenced by temperature, whereas CO2 conversion and CO yield could be manipulated through CO2/CH4 feed ratio. Meanwhile, the GHSV appeared to have a significant influence on the H2/CO ratio and CH4 conversion. From the experimental data, it was found that the 15%Cu/MnO2 catalyst performed best under specified optimal conditions of 800 °C, a CO2/CH4 ratio of 0.6, and a GHSV of 26 L g cat−1 h−1. These optimal conditions resulted in the maximum conversion of CH4 (54.67%), CO2 conversion (47.52%), H2 yield (43.81%), CO yield (36.29%), and H2/CO ratio (1.384). Despite the inevitability of carbon formation resulting from the breakdown of CH4 and CO at high temperatures, the examination of the spent catalysts under optimal conditions yielded a smaller quantity of carbon of approximately 28.27% in comparison to the suboptimal conditions with 55.37%.

Modulation of the Antimelanoma Activity Imparted to Artemisinin Hybrids by the Monoterpene Counterpart.

Molecular hybridization is a widely used strategy in drug discovery and development processes that consists of the combination of two bioactive compounds toward a novel entity. In the current study, two libraries of hybrid derivatives coming from the linkage of sesquiterpene counterparts dihydroartemisinin and artesunic acid, with a series of monoterpenes, were synthesized and evaluated by cell viability assay on primary and metastatic melanoma cell lines. Almost all the obtained compounds showed micromolar antimelanoma activity and selectivity toward the metastatic form of this cancer. Four hybrid derivatives containing perillyl alcohol, citronellol, and nerol as monoterpene counterpart emerged as the best compounds of the series, with nerol being active in combination with both sesquiterpenes, dihydroartemisinin and artesunic acid. Preliminary studies on the mechanism of action have shown the dependence of the pharmacological activity of newly synthesized hybrids on the formation of carbon- and oxygen-centered radical species. This study demonstrated the positive modulation of the pharmacodynamic effect of artemisinin semisynthetic derivatives dihydroartemisinin and artesunic acid due to the hybridization with monoterpene counterparts.

A eutectic mixture catalyzed straight forward production of functional carbon from Sargassum tenerrimum for energy storage application

Here, we present a sustainable and scalable approach for synthesizing functionalized nanomaterials directly from an abundant natural seaweed resource coupled with a green eutectic mixture. The study utilized crushed seaweed granules obtained from fresh brown seaweed Sargassum tenerrimum (ST) and a eutectic mixture generated through the complexation of urea and a metal salt, which act as both solvent and catalyst to facilitate the straightforward production of metal oxide functionalized nanomaterials. Subjecting seaweed granules and the eutectic mixture to pyrolysis at temperatures between 700 °C and 900 °C in a nitrogen (N2) atmosphere resulted in the formation of ST-derived carbon (STC) functionalized with β-MnO2. The nanoneedles thus synthesized were examined for their electrochemical properties in both three-electrode and two-electrode configurations, employing 6 M KOH and 1 M Na2SO4 as electrolytes. Within the three-electrode framework, β-MnO2 functionalized STC at 800 °C (MSTC-8) displayed a remarkable specific capacitance, of 685.1 F g−1 in alkaline electrolyte and 308.3 F g−1 in neutral electrolyte at 0.1 A g−1, demonstrating a superior performance compared to MSTC-7 and MSTC-9. Additionally, two-electrode experiments and evaluations of cyclic stability were performed on MSTC-7, MSTC-8, and MSTC-9 symmetric supercapacitors. The fabricated symmetric supercapacitor in Na2SO4 with the operational voltage window up to 1.7 V, achieved a maximum energy density of 45.5 Wh/kg and a power density of 172.66 W kg−1. Moreover, the current investigation highlights the enduring performance of MSTC-8//MSTC-8 symmetric supercapacitor, with a capacitance retention of 95 % and 80 % over 20,000 cycles in KOH and Na2SO4 electrolytes respectively.

A study on combination of alkaline treatment and PLA/f-CNTs composite coating on corrosion, biocompatibility and antibacterial activity of Mg alloy

The present study explores the effect of combined alkaline treatments (NaOH) and the incorporation of functionalized carbon nanotubes (f-CNTs) into poly(lactic acid) (PLA) composite coatings on the corrosion resistance, biocompatibility, and antibacterial efficacy of AZ31 magnesium (Mg) alloy. Various pretreatment techniques and coating layers have been found to exert considerable influence on the phase composition, morphology, thickness, wettability, as well as corrosion resistance, and biological characteristics of the Mg alloy. The formation of an Mg(OH)2 layer on alkaline-treated Mg alloy has proven to enhance hydrophilicity, corrosion resistance, and biocompatibility. Moreover, the findings highlight that incorporating f-CNTs into PLA improves the corrosion resistance, cytocompatibility, and antibacterial activity of Mg alloy in physiological solutions and the extent of these improvements is related to the quantity of f-CNTs present in the composite coating. Additionally, the outcomes have shown that the inclusion of f-CNTs promotes the formation of carbonate based precipitates during a 14-day immersion in Ringer's solution. Overall, the combination of alkaline treatments and the PLA/f-CNTs composite coating is showcased as a promising surface modification approach for orthopedic applications.

Investigation of limiting H2O/CO2 co-electrolysis to convert renewable electricity into chemical energy using solid oxide electrolysis cell

H2O/CO2 co-electrolysis offers an efficient way to convert renewable electricity into chemical energy. However, carbon deposition is a serious problem for H2O/CO2 co-electrolysis. In this work, limiting electrolytic potential, limiting electrolytic voltage and conversion ratios of H2O/CO2 co-electrolysis are investigated. At low temperatures, the limiting potential of H2O/CO2 co-electrolysis is low and the conversion ratio cannot reach high because solid carbon is easily formed through CO electrolysis or disproportionation reactions. At high temperatures, the electrolytic voltage and conversion ratios of H2O and CO2 can reach high because CO electrolysis or disproportionation reactions are not easy to take place. The conversion ratios of CO2 and H2O can reach 99.6 % and 99.4 % at the H2O/CO2 ratio of 1:1 and 1273 K without solid carbon formation. The polarization resistance of fuel electrode has different effects on the conversion ratios of CO2 and H2O under different conditions, which is obvious at low temperatures and high polarization resistance of fuel electrode. The conversion ratios of CO2 and H2O under limiting electrolysis condition decrease from 9.8 % to 36.6 %–1.8 % and 8.5 % when the polarization resistance of fuel electrode increases from 0 to 0.1 Ω cm2 at the H2O/CO2 ratio of 1:2 and 773 K.

Origins of High Air Sensitivity and Treatment Strategies in O3-Type NaMn1/3 Fe1/3Ni1/3O2.

Sodium-ion layered oxides are one of the most highly regarded sodium-ion cathode materials and are expected to be used in electric vehicles and large-scale grid-level energy storage systems. However, highly air-sensitive issues limit sodium-ion layered oxide cathode materials to maximize cost advantages. Industrial and scientific researchers have been developing cost-effective air sensitivity treatment strategies with little success because the impurity formation mechanism is still unclear. Using density functional theory calculations and ab initio molecular dynamics simulations, this work shows that the poor air stability of O3-type NaMn1/3Fe1/3Ni1/3O2 (NMFNO) may be as follows: (1) low percentage of nonreactive (003) surface; (2) strong surface adsorption capacity and high surface reactivity; and (3) instability of the surface sodium ions. Our physical images point out that the high reactivity of the NMFNO surface originates from the increase in electron loss and unpaired electrons (magnetic moments) of the surface oxygen active site as well as the enhanced metal coactivation effect due to the large radius of the sodium ion. We also found that the hydrolysis reaction requires a higher reactivity of the surface oxygen active site, while the carbon hybridization mode transformation in carbonate formation depends mainly on metal activation and does not even require the involvement of surface oxygen active sites. Based on the calculation results and our proposed physical images, we discuss the feasibility of these treatment strategies (including surface morphology modulation, cation/anion substitution, and surface configuration design) for air-sensitive issues.

Sludge-derived biochar improves sludge electro-dewatering performance: Conductivity analysis

The application of Coupled Electro-dewatering (EDW) with Carbon Materials has demonstrated significant potential in the efficient deep dewatering and solid-liquid separation of activated sludge. In this study, Fe-loaded sludge-based biochar (SBB) was synthesized via FeCl3 impregnation, and the physicochemical properties of SBB were comprehensively characterized using XRD, Raman spectroscopy, BET analysis, FTIR, and XPS. The results demonstrated that the elevation of pyrolysis temperature facilitated the formation of graphitic carbon and graphitic nitrogen structures within the SBB, thereby augmenting current transport in the solid phase of the sludge. Meanwhile, the Fe material present on the surface of SBB undergoes dissolution in the sludge supernatant, thereby releasing Fe ions into the liquid phase and augmenting the conductivity of the liquid system. After the addition of SBB, the sludge showed an increase in Zeta potential and conductivity, along with a pH shift towards acidity, thus improving the conditions for EDW processes. The results obtained from the EDW analysis demonstrated that the application of SBB@800 significantly contributed to the enhancement of both initial current and dewatering limit, leading to a notable reduction in sludge water content from 57.2 % to 40.7 %. This study emphasizes the influence of temperature on physicochemical properties of SBB and its role in EDW, proposing an environmentally friendly approach for advanced sludge treatment using carbon materials and EDW synergy while providing insights for designing carbon materials to enhance EDW performance.

Insertion reactions of CO2 and COS into metal-alkoxide bonds: Reactivity differences on copolymer formation with epoxides

This minireview is written to explain (speculate) upon the reasons for the dramatic differences in product distribution observed upon coupling of carbon dioxide (CO2) or carbonyl sulfide (COS) with specific epoxides under the same catalytic reaction conditions. That is, based on known results of CO2 or COS reactivities with well-defined metal-alkoxide and -phenoxide complexes, the formation of cyclic carbonates vs polycarbonates from CO2 as compared to COS is rationalized for epoxides possessing bulky substituents. This comparison concludes that although copolymers produced from CO2 and COS with epoxides are structurally similar, COS is not a good model for CO2 reactivity in these processes.

A coupled three-dimensional wormhole modeling in heterogenous carbonate lithology in limited-entry and openhole completions

Wormhole propagation in carbonate formation is a well-researched area with several proposed empirical, analytical, and numerical models to predict the process efficiency. The most reliable and up-to-date model is the two-scale continuum (TSC) model, based on numerical simulation of reactive transport in a porous medium. The model has been utilized in two and occasionally in three-dimensional space but has yet to consider the lithology impact in three-dimensional space (3D). This study demonstrated the impact of lithology considering both openhole and limited-entry completion in 3D space. Moreover, the model considered the acid temperature impact on acidizing efficiency. Results showed that limited entry results in a longer wormhole at the expense of its coverage along the wellbore. Similarly, the higher the number of perforations, the lower the wormhole radius but the higher the coverage. Increasing acid temperature results in better dolomite and lower limestone acid stimulation efficiency. In mixed mineralogy, the positive impact of temperature appears at 50 °C and higher. Wormholes propagate in the limestone sections in layered formation with openhole completion, leaving the dolomite under-stimulated, even at high acid temperatures. Limited entry completion in dolomite layers did not prevent the acid from traveling to the limestone layers but provided limited stimulation in the dolomite section. This is the first study to utilize the TSC model to predict the acid stimulation outcomes at field conditions in 3D space.

Simultaneous production of syngas and carbon nanotubes from CO2/CH4 mixture over high-performance NiMo/MgO catalyst

Direct conversion of biogas via the integrative process of dry reforming of methane (DRM) and catalytic methane decomposition (CDM) has received a great attention as a promising green catalytic process for simultaneous production of syngas and carbon nanotubes (CNTs). In this work, the effects of reaction temperature of 700–1100 °C and CH4/CO2 ratio of biogas were investigated over NiMo/MgO catalyst in a fixed bed reactor under industrial feed condition of pure biogas. The reaction at 700 °C showed a rapid catalyst deactivation within 3 h due to the formation of amorphous carbon on catalyst surface. At higher temperature of 800–900 °C, the catalyst can perform the excellent performance for producing syngas and carbon nanotubes. Interestingly, the smallest diameter and the highest graphitization of CNTs was obtained at high temperature of 1000 °C, while elevating temperature to 1100 °C leads to agglomeration of Ni particles, resulting in a larger size of CNTs. The reaction temperature exhibits optimum at 800 °C, providing the highest CNTs yield with high graphitization, high syngas purity up to 90.04% with H2/CO ratio of 1.1, and high biogas conversion (XCH4 = 86.44%, XCO2 = 95.62%) with stable performance over 3 h. The typical composition biogas (CH4/CO2 = 1.5) is favorable for the integration process, while the CO2 rich biogas caused a larger grain size of catalyst and a formation of molybdenum oxide nanorods (MoO3). The long-term stability of NiMo/MgO catalyst at 800 °C showed a stable trend (> 20 h). The experimental findings confirm that NiMo/MgO can perform the excellent activity and high stability at the optimum condition, allowing the process to be more promising for practical applications.

Insight into the Mechanism of CO2 Chemical Fixation into Epoxides by Windmill-Shaped Polyoxovanadate and n-Bu4NX (X = Br, I).

Carbon dioxide (CO2) coupled with epoxide to generate cyclic carbonate stands out in carbon neutrality due to its 100% atom utilization. In this work, the mechanism of CO2 cycloaddition with propylene oxide (PO) cocatalyzed by windmill-shaped polyoxovanadate, [(C2N2H8)4(CH3O)4VIV4VV4O16]·4CH3OH (V8-1), and n-Bu4NX (X = Br, I) was thoroughly investigated using density functional theory (DFT) calculations. The ring-opening, CO2-insertion, and ring-closing steps of the process were extensively studied. Our work emphasizes the synergistic effect between V8-1 and n-Bu4NX (X = Br, I). Through the analysis of an independent gradient model based on Hirshfeld partition (IGMH), it was found that the attack of n-Bu4NX (X = Br, I) on Cβ of PO triggers a distinct attractive interaction between the active fragment and the surrounding framework, serving as the primary driving force for the ring opening of PO. Furthermore, the effect of different cocatalysts was explored, with n-Bu4NI being more favorable than n-Bu4NBr. Moreover, the role of V8-1 in the CO2 cycloaddition reaction was clarified as not only acting as Lewis acid active sites but also serving as "electron sponges". This work is expected to advance the development of novel catalysts for organic carbonate formation.

Effects of biochar and magnesium oxide on cadmium immobilized by microbially induced carbonate: Mobilization or immobilization in alkaline agricultural soils?

Microbially induced carbonate precipitation (MICP) is a promising technique for remediating heavy metal-contaminated soils. However, the effectiveness of MICP in immobilizing Cd in alkaline calcareous soils, especially when applied in agricultural soils, remains unclear. Biochar and magnesium oxide are two environmentally friendly passivating materials, and there are few reports on the combined application of MICP with passivating materials for remediating heavy metal-contaminated soils. Additionally, the number of treatments with MICP cement and the concentration of calcium chloride during the MICP process can both affect the effectiveness of heavy metal immobilization by MICP. Therefore, we conducted MICP and MICP-biochar-magnesium oxide treatments on agricultural soils collected from Baiyin, Gansu Province (pH = 8.62), and analyzed the effects of the number of treatments with cement and the concentration of calcium chloride on the immobilization of Cd by MICP and combined treatments. The results showed that early-stage MICP could immobilize exchangeable cadmium and increase the residual cadmium content, especially with high-concentration calcium chloride MICP treatment. However, in the later stage, soil nitrification and exchange processes led to the dissolution of carbonate-bound cadmium and cadmium activation. The fixing effect of MICP influence whether the MICP-MgO-biochar is superior to the MgO-biochar. Four treatments with cement were more effective than single treatment in MICP-biochar-magnesium oxide treatment, and the MICP-biochar-magnesium oxide treatment with four treatments was the most effective, with passivation rates of 40.7% and 46.6% for exchangeable cadmium and bioavailable cadmium, respectively. However, attention should be paid to the increase in soil salinity. The main mechanism of MICP-magnesium oxide-biochar treatment in immobilizing cadmium was the formation of Cd(OH)2, followed by the formation of cadmium carbonate.

Microbial Ecology of an Arctic Travertine Geothermal Spring: Implications for Biosignature Preservation and Astrobiology.

Jotun springs in Svalbard, Norway, is a rare warm environment in the Arctic that actively forms travertine. In this study, we assessed the microbial ecology of Jotun's active (aquatic) spring and dry spring transects. We evaluated the microbial preservation potential and mode, as well as the astrobiological relevance of the travertines to marginal carbonates mapped at Jezero Crater on Mars (the Mars 2020 landing site). Our results revealed that microbial communities exhibited spatial dynamics controlled by temperature, fluid availability, and geochemistry. Amorphous carbonates and silica precipitated within biofilm and on the surface of filamentous microorganisms. The water discharged at the source is warm, with near neutral pH, and undersaturated in silica. Hence, silicification possibly occurred through cooling, dehydration, and partially by a microbial presence or activities that promote silica precipitation. CO2 degassing and possible microbial contributions induced calcite precipitation and travertine formation. Jotun revealed that warm systems that are not very productive in carbonate formation may still produce significant carbonate buildups and provide settings favorable for fossilization through silicification and calcification. Our findings suggest that the potential for amorphous silica precipitation may be essential for Jezero Crater's marginal carbonates because it significantly increases the preservation potential of putative martian organisms.

Controlling surface chemistry in cold sintering to advance battery materials

Cold sintering is a recently introduced densification method that is of interest due to the lower energy used in the process, the ability to densify metastable materials, the ability to integrate materials to develop unique composites, and the ability to synthesis materials that can be more easily recycled. Collectively, these advantages make cold sintering a promising approach for processing of battery components, and co-sintering into all solid-state batteries. To obtain high electrochemical performance with cold sintering, detailed control of the surface chemistry of powders is needed, to avoid or minimize the impact of carbonate formation in grain boundaries, and to limit concentrations of secondary phases that are a result of incongruent dissolution processes. In this paper, we outline the importance of surface chemical reactions of powders in cold sintering, and the mitigating processes that can be adopted to control these reactions and obtain high performance and unique opportunities for Li and Na-oxide secondary batteries. We focus on a series of examples that demonstrate how the control of low temperature densification (cold sintering) can address the environmental sensitivity of many battery materials, and highlight the issues faced and open questions. These examples include cold sintering of air-sensitive solid electrolytes, re-processing of crushed solid electrolytes, surface passivation of air-sensitive active materials for processing in air, and fabrication of solid-solid macroscopic interfaces for solid-state batteries.

Tree age affects carbon sequestration potential via altering soil bacterial community composition and function.

Among various factors related to the forest carbon pool, the tree stand age, which interacts with soil organic matter, decomposition rates, and microbial activity, is essential and cannot be disregarded. However, knowledge about how tree phases influence soil carbon sinks is not adequate. This study sampled Larix kaempferi (Japanese larch) plantations with different tree stand ages to investigate the temporal dynamics of soil carbon sink in the forest. Physiochemical analyses and high-throughput sequencing results further revealed the interactions of tree stands and their related rhizosphere microbiome. It was found that microbial composition and metabolic activity were significantly affected by different tree ages, whose structures gradually diversified and became more stable from young to mature forests. Many keystone taxa from the phyla Chloroflexi, Proteobacteria, Acidobacteriota, and Nitrospirota were found to be associated with carbon transformation processes. Interestingly, the carbon resource utilization strategies of microbial groups related to tree ages also differed, with near-mature forest soils showing better labile carbon degradation capacity, and mature forests possessing higher degradation potential of recalcitrant carbon. Age-altered tree growth and physiology were found to interact with its rhizosphere microbiome, which is the driving factor in the formation and stability of forest soil carbon. This study highlighted that the tree age-associated soil microbiomes, which provided insights into their effects on soil carbon transformation, were significant in enhancing the knowledge of carbon sequestration in L. kaempferi plantations.

P/N-containing SiO2 flame retardant particles formed by in-situ hydrolysis for significantly improve the flame retardancy and toughness of epoxy resins

To obtain flame retardants with more efficient and multidimensional flame retardant modes, this work formed P/N-containing silica flame retardants (PBPSi) by hydrolysis and used them in epoxy resins (EP) to give them good flame retardant properties. The hydrolyzed SiO2 flame retardant builds an integrated flame-retardant structure and a concentrated stress-bearing point, the EP has good fire resistant properties and toughness. Allowing the addition of 7-PBPSi/EPPBPSi to enable EP to achieve a UL-94 rating of V-0, and the impact strength of 5-PBPSi/EP reached 52.9 kJ/m2. In addition, PBPSi has good performance in inhibiting heat release and toxic gas release, and the PHRR and THR of 7-PBPSi/EP were reduced by 54.6 % and 24.6 %, respectively, compared with pure EP, the content of CO and CO2 also decreased. The analysis of the flame retardant mechanism indicated that PBPSi played a flame retardant role in the biphasic phase through the catalytic carbon formation in the condensed phase and the synergistic dilution of flammable gases and trapping of free radicals by P/N synergistic.

Incorporation of composite metal-PVP derived carbon membranes for the percrystallisation of salt water

In this research using supported metal‑carbon membranes in a membrane percrystallisation application, we investigated the influence of metal ions on the formation of carbon during carbon membrane synthesis by combining polyvinylpyrrolidone (PVP) with various metal compounds, including zinc, potassium, barium, sodium, magnesium, calcium, and strontium, through calcination at 700 °C in a nitrogen atmosphere for the first time. These carbon membranes were then subjected to continuous percrystallisation experiments to produce dry salt crystals from salt solutions. The feed solution (3.5, 10, 20 wt% of salt) were used at 30, 50, and 70 °C for the performance evaluation. Intriguingly, the addition of metal elements to the PVP solution resulted in an enhancement in the total pore volume and surface area of the resulting carbon membranes. The PVP-Zn precursor exhibited the highest increase with a maximum improvement of 99 fold. Moreover, when compared to the PVP membranes alone, the composite membranes also exhibited higher fluxes. Among the tested composite carbon membranes, PVP-Ca, PVP-Zn, and PVP-Mg demonstrated the highest flux values, reaching an impressive 55 kg.m−2.h−1. Additionally, these membranes exhibited self-elimination, where salt was effectively removed from the membrane surface during percrystallisation testing. Thus, these membranes have the potential to be employed in desalination applications.