sakurajunjun

[sakurajunjun]

Coal-based S hybrid self-doped porous carbon for high-performance supercapacitors and potassium-ion batteries

coal activated carbon  A hybrid composed of sulfur self-doped 3D hierarchical porous carbon (S-3DHPC) with a high defect density area and a high specific surface is prepared through direct carbonization of coal and activators without any additional template. The synthesized S-3DHPC is directly used as an electrode for supercapacitors and potassium ion batteries. The large surface area of the three-dimensional carbon network allowed full contact of the electrolyte with the electrode interface, and the transport path of the electrolyte ions and K+ is shorter. In addition, S-type doping in hierarchical porous carbon improves the electronic conductivity and provides superior electrochemical performance. The S-3DHPC electrode with 431.7 F g−1 at 1 A g−1 in a 3 M KOH electrolyte demonstrates an adequate rate performance and cycle stability. In particular, the assembled S-3DHPC-based flexible symmetric supercapacitor exhibits a high energy density of 17.8 Wh kg−1 at a power density of 652 W kg−1. Furthermore, S-3DHPC as the anode for K-ion batteries exhibits a high reversible capacity of 212.9 mAh g−1 at 50 mA g−1, an excellent rate capability, and outstanding cycling performance. carbon powder Therefore, S-3DHPC has broad application prospects as a high-performance energy storage electrode material.

[sakurajunjun]

An experimental and theoretical study of the adsorption removal of toluene and chlorobenzene on coconut shell derived carbon

activated carbon suppliers The adsorption performance of toluene and chlorobenzene on prepared coconut shell derived carbon (CDC) is investigated and compared with commercial activated carbon (CAC) by experiment and theory calculation. Textural properties of prepared adsorbents are characterized by N2 adsorption, infrared spectra (FT-IR), Raman spectra and X-ray photoelectron spectra (XPS). Adsorption isotherms of toluene and chlorobenzene are obtained and fitted using structure optimizations, Grand Canonical Monte Carlo (GCMC) simulation and thermodynamic models. The results indicate that CDC shows better volatile organic compounds (VOCs) removal performance than CAC, and chlorobenzene is easily adsorbed than toluene. On the aspect of textural characteristics, CDC possesses more micropores ratio and narrower pore size distribution than CAC. Furthermore, amounts of electron-withdrawing carbonyl groups on the CAC coconut granular carbon surface reduce the electron density of adsorbents, thus weakening the interaction between VOCs and adsorbents. On the aspect of model fitting, the Yoon and Nelson (Y-N) and Dubinin-Astakhov (D-A) models can well describe the dynamic adsorption and the adsorption equilibrium of toluene and chlorobenzene on CDC respectively. It is believed that substituent groups of adsorbates, making the charge distribution deviate, lead to adsorption potentials of chlorobenzene larger than toluene. In general, both the pore structure and the surface property of adsorbents affect the VOCs adsorption behaviors on CDC.

[sakurajunjun]

Spin-photon entanglement interfaces in silicon carbide defect centers

abrasive manufacturer Optically active spins in solid-state systems can be engineered to emit photons that are entangled with the spin in the solid. This allows for applications such as quantum communications, quantum key distribution, and distributed quantum computing. Recently, there has been a strong interest in silicon carbide defects, as they emit very close to the telecommunication wavelength, making them excellent candidates for long range quantum communications. In this work we develop explicit schemes for spin-photon entanglement in several SiC defects: the silicon monovacancy, the silicon divacancy, and the NV center in SiC. silicon carbide distributors Distinct approaches are given for (i) single-photon and spin entanglement and (ii) the generation of long strings of entangled photons. The latter are known as cluster states and comprise a resource for measurement-based quantum information processing.

[sakurajunjun]

Predicting Two-Dimensional Silicon Carbide Monolayers

silicon carbide distributors Intrinsic semimetallicity of graphene and silicene largely limits their applications in functional devices. Mixing carbon and silicon atoms to form two-dimensional (2D) silicon carbide (SixC1-x) sheets is promising to overcome this issue. Using first-principles calculations combined with the cluster expansion method, we perform a comprehensive study on the thermodynamic stability and electronic properties of 2D SixC1-x monolayers with 0 ≤ x ≤ 1. Upon varying the silicon concentration, the 2D SixC1-x presents two distinct structural phases, a homogeneous phase with well dispersed Si (or C) atoms and an in-plane hybrid phase rich in SiC domains. While the in-plane hybrid structure shows uniform semiconducting properties with widely tunable band gap from 0 to 2.87 eV due to quantum confinement effect imposed by the SiC domains, the homogeneous structures can be semiconducting or remain semimetallic depending on a superlattice vector which dictates whether the sublattice symmetry is topologically broken. Moreover, we reveal a universal rule for describing the electronic properties of the homogeneous SixC1-x structures. These findings suggest that the 2D SixC1-x monolayers may present a new "family" of 2D materials, with a rich variety of properties for applications in electronics and optoelectronics. abrasive manufacturer

[sakurajunjun]

Lithium recovery from spent Li-ion batteries using coconut shell activated carbon

coconut granular carbon  Lithium is one of scarce natural resources in the world that need to be preserve. One of the way in preserving the resource is by recovery the rich source of the lithium such as in the spent batteries. It is necessary to develop a recovery method which is efficient and low-cost to be able to recover the lithium in an economic scale. In this study, low-cost activated carbon (AC) from coconut shell charcoal was prepared by chemical and physical activation methods and tested for Li removal from Co, Mn, and Ni ions in semi-continuous columns adsorption experiments. The maximum surface area is 365 m2/g with the total pore volume is 0.148 cm3/g that can be produced by physical activation at 800 °C. In the same activation temperature, activation using KOH has larger ratio of micropore volume than physical activation. Then, the adsorption capacity and selectivity of metal ions were investigated. A very low adsorption capacity of AC for Li ions in batch adsorption mode provides an advantage in column applications for separating Li from other metal ions. The AC sample with chemical activation provided better separation than the samples with physical activation in the column adsorption method. During a certain period of early adsorption (lag time), solution collected from the column outlet was found to be rich in Li due to the fast travel time of this light element, while the other heavier metal ions were mostly retained in the AC bed. The maximum lag time is 97.3 min with AC by KOH activation at 750 °C. activated carbon suppliers

[sakurajunjun]

Effect of ammonia and boron modifications on the surface and hydrogen sorption characteristics of activated carbons from coal

coal activated carbon  In this study, a synthesis procedure was adopted to prepare boron following nitrogen modified activated carbons from coals collected from Kilimli Zonguldak in Turkey. The effects of ammonia and boron modification on the surface and hydrogen sorption characteristics of these coal based activated carbons were investigated. The modification process was carried out by treatment of potassium hydroxide modified activated carbons with ammonia solution, followed by borax decahydrate solutions at various concentrations (0.025–0.1 M). The porous structure of the samples was characterized by using N2 adsorption-desorption data measured at 77.4 K for the relative pressures in the range P/P0 = 0–1. The resulting samples were in irregular structures having high microporosity. The surface area of the sample characterized by the Brunauer-Emmett-Teller model, having a value of 2195 m2/g by ammonia treatment, increased to 3037 and 2661 m2/g after treatments with the 0.075 M and 0.1 M borax decahydrate solutions, respectively. Hydrogen uptake capacities in the range 2.77–4.14 % wt were obtained by borax decahydrate treatments of the ammonia modified samples, whereas the ammonia treated sample had a capacity of 2.35 % wt before boron modifications. 0.075 M borax decahydrate-ammonia treated sample had the highest surface area and total pore volumes among all the other samples obtained. Increasing borax decahydrate concentration in the range 0.025–0.075 M resulted in the increase of hydrogen uptake capacities due to the improvement in surface characteristics including microporous structure and the affinities of nitrogen and boron to hydrogen. The process adopted for boron modification followed by ammonia treatment of the potassium hydroxide activated coal-based carbons yielded improved surface and hydrogen sorption characteristics as compared to the unmodified carbons. carbon powder

[sakurajunjun]

Robust removal of phenolic compounds from coal pyrolysis wastewater using anoxic carbon-based fluidized bed reactor

coal activated carbon suppliers Coal industry provided various carbon derived products, but it also caused serious environmental pollution by phenolic wastewater emission. By in-situ applications of coal-derived carriers, carbon-based fluidized bed reactors established a sustainable system that realized byproducts recycling and waste elimination, contributing to cleaner production of coal industry. Benefitted from adsorption capacity, powdered activated carbon/lignite activated coke-based fluidized bed reactors significantly promoted start-up and recovery efficiency with higher phenolic degradation rate than activated sludge reactor (avg. 90% vs 70%) when total phenols ranged at 250–350 mg/L, whereas iron-carbon (Fe–C)-based reactor showed the highest stability (70 ± 5%) under supreme phenolic impact (450 mg/L). Combined with adsorption capacity and activated sludge properties, resilient adsorption benefited lignite activated coke-based reactor with toxicity alleviating while intensified sludge flocs equipped Fe–C-based reactor with superior resistance. Moreover, Brachymonas genus provided microbial basis for robust performance of carbon-based systems in methylphenolic degradation. Higher abundance of functional genes for demethylation and cleavage of aromatic ring contributed to superior methylphenolic degradation for fluidized bed reactors in contrast to activated sludge reactor, while up-regulated oxidative stress evidenced superior oxidative resistance of Fe–C-based reactor. In summary, carbon-based fluidized bed reactors provided a cost-efficient and sustainable way for coal pyrolysis wastewater treatment. powdered-activated-carbon.com

[sakurajunjun]

Silicon carbide whisker-mediated transformation of cotton (Gossypium hirsutum L.)

www.hslabrasive.com Plant transformation methods are invaluable biotechnological tools to generate specific and targeted genetic variation for performance improvement of crop plants. Genetic information is created by proper modification during gene cloning flanked by proper regulatory sequences and delivered to plants via -different plant transformation techniques. Due to being a multipurpose plant, cotton has been subjected to different genetic transformation methods to provide the breeders with an opportunity to develop alien traits or improve the endogenous gene performance that are very difficult or impossible to develop through conventional breeding methods. Here we describe the novel physical way of cotton transformation with different genes by using embryogeneic calli as continuous source of explants. silicon carbide abrasive

[sakurajunjun]

Adsorption of Cd (II) on Modified Granular Activated Carbons: Isotherm and Column Study

In this work, equilibrium and dynamic adsorption tests of cadmium Cd (II) on activated carbons derived from different oxidation treatments (with either HNO₃, H₂O₂, or NaOCl, corresponding to GACoxN, granular activated carbon supplier  GACoxP, and GACoxCl samples) are presented. The oxidation treatments determined an increase in the surface functional groups (mainly the acidic ones) and a decrease in the pHPZC (except for the GACoxCl sample). A slight alteration of the textural parameters was also observed, which was more significant for the GACoxCl sample, in terms of a decrease of both Brunauer-Emmett-Teller (BET) surface area and micropore volume. Adsorption isotherms were determined for all the adsorbents and a significant increase in the adsorption performances of the oxidized samples with respect to the parent material was observed. The performances ranking was GACoxCl > GACoxP > GACoxN > GAC, likely due to the chemical surface properties of the adsorbents. Dynamic tests in a fixed bed column were carried out in terms of breakthrough curves at constant Cd inlet concentration and flow rate. GACoxCl and GACoxN showed a significantly higher value of the breakpoint time, likely due to the higher adsorption capacity. Finally, the dynamic tests were analyzed in light of a kinetic model. In the adopted experimental conditions, the results showed that mass transfer is controlled by internal pore diffusion, in which surface diffusion plays a major role. https://www.yrdactivatedcarbon.com

[sakurajunjun]

Cellular toxicity of silicon carbide nanomaterials as a function of morphology

 silicon carbide abrasive Silicon carbide has been shown to be biocompatible and is used as a coating material for implanted medical devices to prevent biofilms. Silicon carbide nanomaterials are also promising in cell tracking due to their stable and strong luminescence, but more comprehensive studies of this material on the nanoscale are needed. Here, we studied the toxicity of silicon carbide nanomaterials on human mesenchymal stem cells in terms of metabolism, viability, adhesion, proliferation, migration, oxidative stress, and differentiation ability. We compared two different shapes and found that silicon carbide nanowires are toxic to human mesenchymal stem cells but not to cancer cell lines at the concentration of 0.1 mg/mL. Control silicon carbide nanoparticles were biocompatible to human mesenchymal stem cells at 0.1 mg/mL. We studied the potential mechanistic effect of silicon carbide nanowires on human mesenchymal stem cells' phenotype, cytokine secretion, and gene expression. These findings suggest that the toxic effect of silicon carbide nanomaterials to human mesenchymal stem cells are dependent on morphology. www.hslabrasive.com

[sakurajunjun]

Effect of air pre-oxidization on coal-based activated carbon for methane decomposition to hydrogen

coal-based activated carbon price per ton Oxidization is considered to be an indispensable step for coals with thermoplastic properties to act as the precursor of activated carbon (AC). In this work, the effect of oxidization conditions of coal on the texture and surface properties of resultant ACs and their catalytic performances in decomposition of methane to hydrogen were investigated. The results show that the surface oxygen containing groups of the resultant ACs changed, the surface area of ACs increases from 1892 m2/g to 2407 m2/g, and the mesoporosity significantly increases after the precursor coal is pre-oxidized. The ACs from oxidized coals show higher catalytic activities in methane decomposition reaction than that from raw coal. The ACs prepared from oxidized coal at 373 K show the best stability while the AC from the oxidized coal at 573 K for 4 h exhibits the highest initial activity among the ACs. Additionally, the oxidization time has a negative effect on initial activities but little positive influence on stability of ACs when the precursor is oxidized at 373 K. It is thought that the increased mesoporosity is beneficial to the catalytic activity and stability of AC in methane decomposition to hydrogen.

Highlights

• powder activated carbon

Pre-oxidation affects surface and pore structure of the resultant AC.

•

AC from oxidized coal shows good activity and stability in methane decomposition.

•

High mesoporosity is beneficial to the catalytic activity and stability of AC.

•

Oxidation temperature has a great effect on performance of ACs in methane decomposition.

•

Oxidation time has little positive effect on the stability of ACs in methane decomposition.

[sakurajunjun]

Performance of biomorphic Silicon Carbide as particulate filter in diesel boilers

Biomorphic Silicon Carbide (bioSiC) silicon carbide abrasive suppliers is a novel porous ceramic material with excellent mechanical and thermal properties. Previous studies have demonstrated that it may be a good candidate for its use as particle filter media of exhaust gases at medium or high temperature. In order to determine the filtration efficiency of biomorphic Silicon Carbide, and its adequacy as substrate for diesel particulate filters, different bioSiC-samples have been tested in the flue gases of a diesel boiler. For this purpose, an experimental facility to extract a fraction of the boiler exhaust flow and filter it under controlled conditions has been designed and built. Several filter samples with different microstructures, obtained from different precursors, have been tested in this bench. The experimental campaign was focused on the measurement of the number and size of particles before and after placing the samples. Results show that the initial efficiency of filters made from natural precursors is severely determined by the cutting direction and associated microstructure. In biomorphic Silicon Carbide derived from radially cut wood, the initial efficiency of the filter is higher than 95%. Nevertheless, when the cut of the wood is axial, the efficiency depends on the pore size and the permeability, reaching in some cases values in the range 70-90%. In this case, the presence of macropores in some of the samples reduces their efficiency as particle traps. In continuous operation, the accumulation of particles within the porous media leads to the formation of a soot cake, which improves the efficiency except in the case when extra-large pores exist. For all the samples, after a few operation cycles, capture efficiency was higher than 95%. These experimental results show the potential for developing filters for diesel boilers based on biomorphic Silicon Carbide. red shiliu abrasive

[sakurajunjun]

Trichloroethylene adsorption by fibrous and granular activated carbons: aqueous phase, gas phase, and water vapor adsorption studies

The important adsorption components involved in the removal of trichloroethylene (TCE) by fibrous and granular activated carbons from aqueous solutions were systematically examined. www.granular-activated-carbon.com Namely, adsorption of TCE itself (i.e., TCE vapor isotherms), water molecules (i.e., water vapor isotherms), and TCE in water (i.e., TCE aqueous phase isotherms) were studied, side-by-side, using 20 well-characterized surface-modified activated carbons. The results showed that TCE molecular size and geometry, activated carbon surface hydrophilicity, pore volume, and pore size distribution in micropores control adsorption of TCE at relatively dilute aqueous solutions. TCE adsorption increased as the carbon surface hydrophilicity decreased and the pore volume in micropores of less than 10 A, especially in the 5-8 A range, increased. TCE molecules appeared to access deep regions of carbon micropores due to their flat geometry. The results indicated that characteristics of both adsorbate (i.e., the molecular structure, size, and geometry) and activated carbon (surface hydrophilicity, pore volume, and pore size distribution of micropores) control adsorption of synthetic organic compounds from water and wastewaters. activated carbon supplier south africa The important micropore size region for a target compound adsorption depends on its size and geometry.

[sakurajunjun]

Silicon Carbide Nanoparticles as an Effective Bioadhesive to Bond Collagen Containing Composite Gel Layers for Tissue Engineering Applications

Additive manufacturing via layer-by-layer adhesive bonding holds much promise for scalable manufacturing of tissue-like constructs, specifically scaffolds with integrated vascular networks for tissue engineering applications red shiliu abrasive  . However, there remains a lack of effective adhesives capable of composite layer fusion without affecting the integrity of patterned features. Here, the use of silicon carbide is introduced as an effective adhesive to achieve strong bonding (0.39 ± 0.03 kPa) between hybrid hydrogel films composed of alginate and collagen. The techniques have allowed us to fabricate multilayered, heterogeneous constructs with embedded high-resolution microchannels (150 µm-1 mm) that are precisely interspaced (500-600 µm). Hydrogel layers are effectively bonded with silicon carbide nanoparticles without blocking the hollow microchannels and high cell viability (90.61 ± 3.28%) is maintained within the scaffold. Nanosilica is also tested and found to cause clogging of smaller microchannels when used for interlayer bonding, but is successfully used to attach synthetic polymers (e.g., Tygon) to the hydrogels (32.5 ± 2.12 mN bond strength). This allows us to form inlet and outlet interconnections to the gel constructs. This ability to integrate hollow channel networks into bulk soft material structures for perfusion can be useful in 3D tissue engineering applications. silicon carbide abrasive suppliers

[sakurajunjun]

Dynamic interactions between cyclodextrin, an organic pollutant, and granular activated carbon in column studies

In this study, the dynamic interactions between cyclodextrin (CD), an organic chemical and granular activated carbon (GAC) www.granular-activated-carbon.com were investigated using column studies. Breakthrough curves of a chlorinated solvent, trichloroethylene (TCE) were obtained over a range of concentrations of 2-hydroxypropyl-beta-cyclodextrin (HPCD) (0, 20, and 50 g L(-1)) and flow velocities (1.0, 4.0, and 10.2 mL min(-1)). Important transport parameters (i.e. residence time, dispersion coefficient, retardation factor) were estimated using truncated temporal moment analysis. Our result shows that increasing CD concentration resulted in earlier TCE breakthrough, demonstrated by decreasing residence times which are 306.23, 151.26, and 102.24 pore volumes for 0, 20, and 50 g L(-1) CD respectively. Comparison of the original breakthrough curves (BTCs) under different CD concentrations to the solubility-enhancement-rescaled BTCs showed (1) the presence of CD decreases the relative degree of TCE sorption to GAC and (2) all 3 curves exhibited similar rescaled times at which they reach 50% of the input concentration. The lowest flow rate, (1.0 mL min(-1)), resulted in a more symmetrical BTC, indicating more ideal conditions were achieved under the longer exposure time provided by this flow rate. activated carbon supplier south africa As the flow rate increases the first appearance of TCE in the eluent occurs relatively earlier and exhibits comparatively greater delay in achieving full breakthrough, suggesting non-equilibrium processes are more significant at higher flow rates.

[sakurajunjun]

Subsurface Damage in Polishing Process of Silicon Carbide Ceramic

red shiliu abrasive Subsurface damage (SSD) in the polishing process of silicon carbide (SiC) ceramic presents one of the most significant challenges for practical applications. In this study, the theoretical models of SSD depth are established on the basis of the material removal mechanism and indentation fracture mechanics in the SiC ceramic polishing process. In addition, the three-dimensional (3D) models of single grit polishing are also developed by using the finite element simulation; thereby, the dynamic effects of different process parameters on SSD depth are analyzed. The results demonstrate that the material removal was mainly in brittle mode when the cutting depth was larger than the critical depth of the brittle material. The SSD depth increased as the polishing depth and abrasive grain size increased, and decreased with respect to the increase in polishing speed. The experimental results suggested a good agreement with the theoretical simulation results in terms of SSD depth as a function of polishing depth, spindle speed, and abrasive grain size. silicon carbide abrasive suppliers This study provides a mechanistic insight into the dependence of SSD on key operational parameters in the polishing process of SiC ceramic.

[sakurajunjun]

The effect of nitrogen and/or boron doping on the electrochemical performance of non-caking coal-derived activated carbons for use as supercapacitor electrodes

coal-based activated carbon price per ton Coal-based activated carbons doped with either N or B or a combination of the two were prepared for use as the electrode materials of supercapacitors by ball milling and subsequent activation using Xinjiang non-caking coal, melamine and boric acid as the respective carbon, nitrogen and boron sources. FTIR spectroscopy and XPS reveal that the B and N atoms are substitutionally incorporated into the carbon skeleton. These doped activated carbons contain a large number of mesopores. Cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy show that N- and B-doped activated carbons have a superior capacitance and rate performance to the non-doped one. The B-N co-doped material has the highest specific capacitance of 176 F g−1 at 0.5 A g−1, which is attributed to a synergistic effect of B-N co-doping. The capacitance of the co-doped sample remains at 96% of the original value after 20 000 cycles.powder activated carbon