Different Types Of Carbon Research Articles

Clumped isotopes in modern marine bivalves

Oxygen-isotope measurements of fossil carbonates remain the most common method for paleoclimatic temperature reconstructions. A well-known limitation of this approach is the influence of the oxygen isotope composition of water in which mineralization occurs, which may vary significantly through space and time, and is often difficult to constrain precisely. Carbonate clumped-isotope thermometry is an alternative approach applicable to many carbonates. It is based on measurements of Δ47 (a tracer of small statistical anomalies in the abundance of rare, doubly-substituted carbonate isotopologues), and requires no independent information on the oxygen-isotope composition of parent waters. Here, we report new calibration observations of clumped isotopes in four species of calcitic marine bivalves (A. colbecki, N. cochlear, S. cucullata, M. gigas) from various ecosystems including coastal and deep-sea environments, with calcification temperatures ranging from −2 °C to 27 °C and very different amplitudes of seasonal temperature variability. At two localities with large seasonal temperature variability, calcification time intervals were constrained using a sclerochronological approach to test whether seasonal gradients of temperature can be accurately quantified based on Δ47 measurements.Our results indicate that the mature bivalves we analyzed have clumped-isotope compositions entirely consistent with earlier calibration studies processed in the I-CDES reference frame and based on biogenic/abiotic/synthetic materials. By contrast, juvenile M. gigas oysters yield substantially lower Δ47 values than expected based on their calcification environments, suggesting that their early growth phase is associated with yet poorly understood isotopic biases affecting both δ18Ο and Δ47 values. The link between seawater temperatures and bivalve Δ47 values is thus potentially applicable to seasonal reconstructions, but only if shell sections formed in cold seasons are precisely identified and precisely sampled, and taking into account that winter calcification is likely to be biased due to reduced growth rate. Moreover, the excellent agreement between our observations and the existing I-CDES calibrations further demonstrates the efficacy of the I-CDES standardization approach, and adds to the evidence that many different types of carbonates conform to statistically indistinguishable relationships between Δ47 and crystallization temperature.

In Situ Growth of Pt-Co Nanocrystals on Different Types of Carbon Supports and Their Electrochemical Performance toward Oxygen Reduction.

Carbon-supported Pt-M (M = Co, Ni, and Fe) alloy nanocrystals are widely used as catalysts toward oxygen reduction, a reaction key to the operation of proton-exchange membrane fuel cells. Here we report a colloidal method for the in situ growth of Pt-Co nanocrystals on various commercial carbon supports. The use of different carbon supports resulted in not only variations in size and composition for the nanocrystals but also their catalytic activity and durability toward oxygen reduction in acidic media. Among the nanocrystals, those grown on Vulcan XC72 and Ketjenblack EC300J showed the highest specific and mass activities in the 0.1 M HClO4 and 0.05 M H2SO4 electrolytes, respectively. Additionally, the catalysts also showed different durability depending on the strength of the interaction between the nanocrystals and the carbon support. Our analysis demonstrated that the difference in catalytic performance could be ascribed to the distinct effects of carbon support on both the synthetic and catalytic processes.

Stripping and Plating Behavior of Sodium Metal in Carbonate and Ether Electrolytes

Sodium (Na) stripping is a subsurface process, where sodium (Na) metal is oxidized into Na ions and vice versa during the plating process of cell operation. The morphological/structural changes in the metal following the charge transfer during stripping can largely affect the subsequent plating process. While the reactions and kinetics at the electrode-electrolyte interface are being recognized as the primary factor in limiting the applicable capacity of Na metal anode, a unified framework incorporating a detailed electrochemical study of various electrolyte formulations is still lacking. In this work, we used different types of carbonates (PC, PC: FEC) and ether-based solvents (DME, diglyme, and TEGDME) with NaClO4 and NaPF6 salts to explore the compatibility of Na metal in different liquid electrolyte system. The microscopic images were compared in the context of Na deposition and pitting. The electrolyte composition has a distinctive effect on the evolution of the plated and stripped Na profile, and it was observed that TEGDME for both NaClO4 and NaPF6 salts has severe effects of sodium corrosion, evident by large cavities in the Na metal. Dramatic changes in growth morphological variables, particularly thickness, have a large impact on system viability, affecting the packaging, and thus, identifying the prevalence of the Na deposition or stripping is critically important. The dynamic changes in the voltage profile in a symmetric cell setup were also examined during extended cycles to understand the reaction and mass transport limitation in different electrolyte solvents. As the stripping and plating processes are indirect proof of cell aging, the observed behavior of Na metal-salt-solvent interaction in this work will help to highlight the potential for developing a better Na metal system with long term electrochemical performance.

Molecular Characterization of the Organic Fraction of Municipal Solid Waste and Compositional Evolution during Oxidative Processes Assessed by HR-MAS 13C NMR Spectroscopy

The use of high-resolution magic angle spinning (HR-MAS) 13C NMR spectroscopy is proposed here as an innovative and non-destructive approach to investigate the chemical composition of the organic fraction of municipal solid waste (OFMSW) and for monitoring the evolution of their composition during the oxidative iron-based Fenton treatment to which the initial matrix is subjected. The high quality and the good resolution of the 13C HR-MAS NMR spectra allowed an accurate assignment and quantification of the various types of carbon present in the analyzed organic matrix. Moreover, the HR-MAS has also shown its effectiveness in monitoring the different oxidative processes to which the same initially organic matrix has been subjected. The results obtained from the HR-MAS spectra on the collected samples during the different oxidative experiments, indicate that Fenton treatment is able to modify the percentage of the different types of carbons as a function of the concentrations of both Fenton reactants, H2O2 and Fe2+ salt, and of the oxidative process time.

Effects of nitrogen-containing functional groups of reduced graphene oxide as a support for Pd in selective hydrogenation of cinnamaldehyde

The importance of electronic and chemical properties of nitrogen-doped reduced graphene oxide (NRGO) has attracted more attention in recent years. Various carbon–nitrogen bonds with different chemical properties are formed in the process of nitrogen doping (N-doping) of reduced graphene oxide, such as pyrrolic-N, pyridinic-N, and graphitic-N. These types of carbon–nitrogen bonds in the structure are distinctly effective when they are used as catalyst support. This study reveals that various types of carbon–nitrogen bonds of the support affect activity and selectivity of hydrogenation of cinnamaldehyde to hydrocinnamaldehyde reaction differently by palladium active phase. The catalyst supports were synthesized with thermal treatment at three different heat treatment and atmosphere procedures, i.e., 500 and 900 °C, in the presence of ammonia diluted with argon. Various procedures led to different types of carbon–nitrogen bond and different quantity of nitrogen doping of the support. Following the support synthesis, palladium active phase was deposited on the support by an incipient wetness impregnation method. The catalysts were characterized by ICP-OES, XPS, elemental analysis, Raman spectroscopy, FESEM, BET, TPD, TPR, CO chemisorption, and HRTEM. The characterization results showed that Pd dispersion and its size distribution were affected by the quantity and the type of carbon–nitrogen species of the support. The pyridinic nitrogen, as electron acceptor species, seems to have a positive impact on a more uniform distribution of Pd. The catalytic activity was evaluated in a high-pressure bubble column reactor. In this work, the catalyst containing 4.5 wt% Pd supported on NRGO with 2.4% nitrogen and treated at 500 °C showed a maximum conversion of about 98% with high selectivity (96%) for the reaction.

Removal of Some New Direct Sulpho Aryl Azo Dyes from Aqueous Solutions by Adsorption onto Different Types of Carbon(Dept.P)

A new group of direct arylazo dyestuffs that are based on the spiro 2-oxndole (3,2)-1,3' thiazolone moiety was successfully synthesized by the authors [1]. In view of the current interest in utilizing the sulpho arylazo dyestuffs for dyeing different types of fibers, the present paper describes the possibility of using carbon for their removal, as organic pollutants, from aqueous solutions. The removal of these dyestuffs from their aqueous solutions was carried out by using different adsorbents such as granular carbon, carbon soot, and powdered activated carbon (PAC) at different temperatures ranging from 25 C to 60°C. The adsorption of these dyes on different types of carbon has been found to obey the adsorption isotherms like Langmuir, Freundlisch and Brauner Emmitte and Teller (BET) isotherms. It was found that PAC has the highest capacity of adsorption.Carbon soot is recommended to be used for the removal of such type of dyes from their aqueous solutions due to the low cost of its production with respect to PAC and to solve the problem of its accumulation, as a polluting solid waste. Different adsorption parameters were calculated from these models for the interpretation of the adsorption process. It was found that the removal efficiency for color of dyes was over 90% in case of carbon soot and PAC at higher temperatures.

CARBON NANOHORN–BASED NBR HYBRID NANOCOMPOSITES

ABSTRACT Carbon nanohorn (CNH)–filled elastomer hybrid nanocomposites were prepared based on NBR. Three different CNH types were analyzed, each featuring various characteristics such as aggregate structure, specific surface area, surface energy distribution, and electrical conductivity and resulting in different potentials regarding the properties of the developed elastomers. For the CNH types, a high tendency of agglomeration was observed in the pristine state, indicating the need for an effective strategy to break up the agglomerates during the mixing or the compounding procedure to realize their incorporation and sufficient dispersion in a polymer matrix. In addition to the melt mixing technology by means of an internal lab mixer, a discontinuous static and a continuous dynamic latex compounding process were used. Carbon nanotubes and a highly conductive carbon black (Printex) were used as hybrid fillers in the compounds mixed by melt mixing, whereas two different types of carbon black (Printex and Derussol) were also incorporated in the latex experiments. Hybrid nanocomposites with low content of CNHs (≤1 wt%) show an improvement in dynamic-mechanic and physical properties due to distinctive polymer–filler interactions. Dealing with higher amounts of CNHs leads to filler reagglomeration, resulting in deterioration of the elastomer properties. For the electric conductivity assessment, addition of CNH indicates no synergistic effects and no significant increase of the hybrid compounds, which is demonstrated in dielectric measurements, although pristine CNHs are conductive themselves. Elastomer compounds processed via the latex method show enhanced material performance by using the continuous dynamic latex compounding, which is mainly attributed to the dispersion of the hybrid filler.

(Invited) Factors Influencing the Performance of Vanadium Flow Batteries: Electrodes and Electrolytes

There is presently great interest in redox flow batteries1-8 (RFBs) for large-scale energy storage9 due to advantages over other electrical energy storage (EES) technologies, and research activities in this area have grown exponentially in recent years. The vanadium flow battery (VFB), also known as the vanadium redox flow battery (VRFB), is commonly regarded as one of the most promising flow batteries.2-3,10-12 Active areas of research on VFBs include electrolytes,13-16 electrodes,5-7 membranes,8 cell design and modelling,8 and performance and state-of-charge (SoC) monitoring.17-18 In this paper, we will review our work in two areas: kinetics on carbon electrodes and thermal stability of electrolytes.The kinetics of the VII-VIII, VIII-VIV and VIV-VV redox couples have been studied for a range of different carbon materials using a variety of techniques, and it is clear that the kinetic rates depend strongly both on the type of carbon used and on the preparation of the electrode surface. We will discuss our investigations5-7 of the effects of anodic and cathodic pretreatments of carbon on electrode kinetics in the VFB. Using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), we showed for four different types of carbon that electrode treatments at negative potentials enhance the kinetics of VIV-VV and inhibit the kinetics of VII-VIII while electrode treatments at positive potentials inhibit the kinetics of VIV-VV and enhance the kinetics of VII-VIII. These observations may explain conflicting reports in the literature. We examined in detail the potentials required for activation and deactivation of electrodes. The results suggest that interchanging the positive and negative electrodes in a vanadium flow battery (VFB) would reduce the overpotential at the negative electrode and so improve the performance. This is supported by flow-cell experiments. Thus, periodic catholyte-anolyte interchange, or equivalent alternatives such as battery overdischarge, show promise of improving the voltage efficiency of VFBs.We have developed13-16 a standard methodology for measuring the thermal stability of vanadium catholytes based on their induction time for precipitation of V2O3. Using this, we have investigated the thermal stability of typical vanadium flow battery (VFB) catholytes at temperatures in the range 30–70°C for VV concentrations of 1.4–2.2 mol dm-3 and sulfate concentrations of 3.6–5.4 mol dm-3. In all cases, V2O5 precipitates after an induction time, which decreases with increasing temperature. Plots of the logarithm of induction time versus the inverse of temperature (equivalent to Arrhenius plots) show excellent linearity and all have similar slopes, yielding a value of 1.791±0.020 eV for the activation energy. The logarithm of induction time also increases linearly with sulfate concentration and decreases linearly with VV concentration. The slopes of these plots give values of concentration coefficients β S and β V5 which quantify the effects of concentration on induction times. Combining these with the Arrhenius slope, we have constructed a model to predict the stability of sulfate-based vanadium catholytes. The model can also be used as a basis for accelerated testing of the thermal stability of electrolytes.We have investigated a range of additives and shown that many suggested additives are ineffective. However, the Group V elements phosphorus and arsenic in the +5 oxidation state have a significant stabilizing effect. We have also quantified their effect in the temperature range 30-70°C. REFERENCES A.Z. Weber et al., J. Appl. Electrochem. 41, 1137 (2011)M. Skyllas-Kazacos et al., J. Electrochem. Soc. 158, R55 (2011)M.J. Watt-Smith et al., J. Chem. Technol. Biotechnol. 88, 126 (2013)S. Roe et al., J. Electrochem. Soc. 163, A5023 (2016)A. Bourke et al., J. Electrochem. Soc. 163, A5097 (2016)A. Bourke et al., J. Electrochem. Soc. 162, A1547 (2015)M.A. Miller et al., J. Electrochem. Soc. 163, A2095 (2016)D. Reed et al., J. Electrochem. Soc. 163, A5211 (2016)R. M. Darling et al., Energy Environ. Sci ., 7, 3459 (2014)R. M. Darling et al., J. Electrochem. Soc .,163, A5014 (2016)A. K. Manohar et al., J. Electrochem. Soc., 163, A5118 (2016)A. M. Pezeshki et al., J. Electrochem. Soc., 163, A5202 (2016)D. Oboroceanu et al., J. Electrochem. Soc ., 163, A2919 (2016)D. Oboroceanu et al., J. Electrochem. Society, 164, A2101 (2017)D. N. Buckley et al., J. Electrochem. Society, 165, A3263 (2018) Oboroceanu et al., J. Electrochem. Soc ., 166, A2270 (2019)C. Petchsingh et al., J. Electrochem. Soc. 163, A5068 (2016)D. N. Buckley et al., J. Electrochem. Soc., 161 A524 (2014)

Molecular structure characterization of low-medium rank coals via XRD, solid state 13C NMR and FTIR spectroscopy

In-depth understanding of coal molecular structures is crucial to the clean and efficient coal conversion, as they are the dominant factors determining the reactivity and reaction behaviors of coals in thermal conversions such as combustion, pyrolysis, gasification and liquefaction. However, the molecular structures of coals are still far from clear due to the intrinsic complexity and heterogeneity of coals. This work probes the molecular structures of eight coals of various metamorphic grades with combined spectral techniques of X-ray diffraction (XRD), solid state 13C NMR and FTIR spectra. The structural parameters were correlated with the coalification indicator Ro to investigate the structural evolutions during coal metamorphism. Consistent results concerning the structural evolution during coalification were obtained with different techniques. From the parameters of proximate and ultimate analysis, the increasing aromaticity and decreasing aliphatic fractions with rising coalification degree are observed. XRD patterns show the ubiquitous presence of amorphous carbon, the gradually condensing aromatic layers, and the size-growing but graphitizing crystallites during coalification. 13C NMR spectra reveal different types of carbons presented, the increasing aromatic and decreasing aliphatic components, the growing size and weight but reducing number of side-chains of the aromatic clusters. FTIR spectra indicate shortening and reducing of aliphatic chains, as well as enhancing aromaticity with the deepening metamorphism. These findings shed light on the structure features of coals and are potentially useful to the clean and efficient coal utilization.

Fundamental Investigation of Ferrosilicon Production Using Rice Husk and Rubber Tree Bark at 1550°C: Implication for Utilization of Agricultural Waste in Steelmaking Industry

Rice husk is one of the major agricultural wastes in Thailand, which predominately consist of silica up to 90 wt%. Rubber tree bark (RTB) is an agricultural waste from the harvesting of natural rubber, composed of cellulose and rubber parts, which is a carbon-based material. This research aims to investigate the possibility of using rice husk and rubber tree bark as a silica and carbon resources for producing ferrosilicon alloy. Three different types of carbon were used for the investigation: Coal, RTB and Coal-RTB blend. Rice husk ash, iron ore and carbon were blended homogeneously according to their molar ratios. The prepared samples were heated at 1550 °C in argon atmosphere for 30 minutes and thus the metal droplets were produced. The silicon contents in the produced metal droplets were analyzed by using Inductive coupled plasma (ICP). The results show that the metal produced by this method are ferrosilicon alloy with the highest silicon contents in the metal droplets was 45.32 wt% for RTB, while it was 18.25 wt% for coal. This research unlocks the potential of utilization of agricultural waste in steelmaking industry.

Development of quantitative 13C NMR characterization and simulation of C, H, and O content for pyrolysis oils based on 13C NMR analysis.

Bio-oil is a valuable liquid product obtained from pyrolysis of biomass and it contains tens of hundreds of compounds, which brings about difficulties for characterization with various analytical methods. 13C NMR has advantages over other detection methods as it can characterize the entire composition of bio-oil and distinguish different types of carbon. But various shortcomings limit the application of 13C NMR. This study was carried out to develop a quantitative 13C NMR method to determine different functional groups in pyrolysis bio-oils with short NMR time and good accuracy, and propose a simulation of C, H, and O content for pyrolysis oils based on 13C NMR analysis. In order to solve long-term NMR problems, relax reagent has been added and the results show that it is an effective way to shorten the NMR time. Moreover, the aging problem is not obvious in the short-term NMR test, so the effect of aging on the test results can be neglected. Three types of substances with different oxygen content have been employed to verify the feasibility of the C, H, and O calculation methods and the result errors of all elements are small, which shows it is reliable for the simulation data of C, H and O content.

Interlaminar shear strength study on CFRP/Al hybrid laminates with different properties

FML (Fibre Metal Laminate) is a hybrid material that presents outstanding structural properties, such as resistance to cyclic and dynamic loads, together with low specific weight. This material consists of metal sheets alternating to composite material layers. In the present work, the ILSS (Interlaminar Shear Strength) was evaluated for different types of carbon fibre/aluminium FML, produced varying the layer thickness and the bonding solution of layers. In fact, FMLs consisting of one or two metal sheets (a parameter strictly connected to the layer thickness, as the metal/composite volume fraction was kept at constant value) and bonded with structural adhesive or prepreg resin were considered for this study. The ILSS was determined according to the three-point bending method with short beam specimens. The experimental tests evidenced an effect of the adhesion methodology on the ILSS value, while the layer thickness did not influence the interlaminar strength. The mechanical behaviour after the maximum load point was investigated too, evaluating the trend of the shear stress as a function of the loading nose displacement.

Carbon Materials as the Matrices for Sulfur in Li-S Batteries

Development of advanced energy-storage batteries for portable electronic devices and electric vehicles must accomplish several requirements: safety, low-cost, nature friendly, long lifecycle, high energy density, and high theoretical capacity. Lithium-sulfur batteries can execute these requirements. However, the practical application of lithium-sulfur battery is hindered by several major disabilities, such as volumetric expansion of sulfur, structural instability, high self-discharging, poor electronic conductivity of sulfur, and low cycle life. This article deals with different types of carbons as additives in cathode for lithium-sulfur battery.

Chromium (VI) Adsorption on Modified Activated Carbons

The paper presents the research of adsorptive properties of activated carbons to chromium (VI) removal from the water solution. Different types of carbon were investigated: WD-ekstra (WDA), WD-ekstra modified by salt acid WD(HCl) and nitrogen acid WD(HNO3). The adsorption kinetics, influence reaction, temperature and kind of carbon were determined using static methods. The adsorption of chromium (VI) onto all activated carbons was most efficient at pH 2. The time of adsorption balance for carbon WD(HCl) was 2.5 h and for carbon WDA 4.5 h. The influence of carbon modification and temperature on the effectiveness of adsorption of hexavalent chromium was determined on the basis of the Freundlich adsorption isotherm. The research showed that the adsorption capacity of Cr(VI) increased with the increasing temperature of the solution. The most efficient adsorbent in static conditions was found on WD-ekstra modified by HCl. The adsorbent applied in dynamic conditions as the filtration bed (v = 2 m/h, time of retention TR = 420 s, initial concentration C0 = 1 mg/dm3), it removed chromium (VI) from water very effectively. Adsorption capacities after exhaustion of the bed were obtained at PeWD (HCl) = 4.35 mg/g. On the basis of executed research, chromium ions were successfully eliminated onto modified carbon WD(HCl) that makes its employment capabilities in the systems purification of water.

Carbonate clumped isotope (Δ<sub>47</sub>) thermometry andits application in paleoelevation reconstruction

Paleoaltimetry provides crucial constraints on tectonic processes and precise paleotemperature measurement is an important component in paleoelevation reconstruction. Carbonate clumped isotope thermometry is based on homogeneous isotope equilibrium and is used to provide direct estimation of carbonate formation temperature independent of δ 18O of the parent water from which the carbonate formed. The error regarding clumped isotope temperature estimation can be reduced to ±2°C. The characteristics of temperature-dependence, and the small uncertainty using carbonate clumped isotope thermometry, greatly improve accuracy and precision in paleoelevation reconstruction. In this review, we introduce the basic theory, laboratory methodology and standardization processes underpinning carbonate clumped isotope thermometry. Theoretical calculations indicate a linear relationship between parameter Δ47 and 1/ T 2, which establishes the foundation from which carbonate clumped isotopes provide reliable paleotemperatures. The laboratory treatment of carbonate includes two systems: the modified Kiel IV device for small weight samples (0.15−0.2 mg) installed within microvolume nitrogen traps and packed microvolume columns; and a heavy sample device that is installed with McCrea/common bath acid digestion devices, nitrogen traps and packed columns. These systems are designed to remove potential interference from water and hydrocarbons in the CO2. The measurement of purified CO2 is finished on gas source isotope mass ratio spectrometry (IMRS), especially on MAT 253 and 253 Plus machines. The standardization of the Δ47 to an absolute reference frame (ARF) accounts for the non-linearity and scaling effect of the IMRS, and the ARF also enables direct comparison of data from different laboratories. The practical procedure for the standardization includes interpolating the relationship between the measured δ 47 and Δ47 of the equilibrium gases, and conversion of the measured Δ47 to theoretical values to derive an empirical transfer function. Due to the great potential for solving Earth science problems, empirical calibration of the carbonate clumped isotope thermometry has been explored over a wide range of temperature in different types of carbonates, but is still plagued by discrepancies between different calibrations, probably due to variability in acid preparation, CO2 purification and data reduction methods. We summarized all the published synthetic calcite data to ARF with the same acid fractionation factor and yield a composite empirical calibration that could resolve the discrepancies between different calibrations. However, bio-genetic carbonates still fail to yield a universal empirical calibration, even when using the same methodology. The cause of this difference is probably due to different environmental, species discrimination and vital effects. The application of carbonate clumped isotope thermometry to paleoaltimetry is based on the theory that the δ 18O of precipitation (meteoric water) decreases proportionally as elevation increases. Knowing the formation temperature and δ 18O of carbonate, we can trace back to the precise value of δ 18O in precipitation, and then, using the theoretical model, or empirical relationship, between the δ 18O of precipitation and elevation, reconstruct paleoelevation. Furthermore, clumped isotope thermometry can be used to test for diagenetic effects on pedogenic samples to ensure they retain original sedimentary isotopic compositions. We summarized previous applications of carbonate clumped isotope thermometry to accurately and precisely reconstruct the paleoelevation of the Andes mountains, Western North America and the Tibetan Plateau to provide insights into the uplift history and geodynamic process of those regions. Despite the great potential for carbonate clumped isotopes in paleoelevation reconstruction, there are still challenges regarding equilibrium mechanisms, the discrepancies between different calibrations and the broader application in different carbonates. To resolve these challenges, more theoretical research is needed, as well as improving the resolution of IMRS.

Intercalating Solid State Electrolyte Based Composite Electrode for Lithium-Sulfur Batteries

There is a necessity for extending the cycle life and rate capability on lithium-sulfur (Li-S) batteries. Prevention of the polysulfide shuttle, suppression of the lithium dendrite formation, and construction of an efficient electrode architecture are the main challenges in advancing Li-S battery technology 1. In the present work, we introduce an intercalating solid state electrolyte (ISSE) made of nanoparticles of lithium cobalt oxide (LCO). The ISSE is combined with the sulfur to form a composite electrode to enhance the cathode architecture suitable for supporting a high sulfur loading in Li-S electrodes. In addition, we present the improved performance of the ISSE composite cathode with our nonporous mixed conduction membrane (MCM) made of LCO and polymer electrolytes. The feasibility of this concept is shown the discharge and charge curves plot (Fig 1). In our past studies MCM was found to be effective in suppressing the polysulfide shuttle and therefore provides high capacity retention and extension of the cycle life 2. The MCM layer can be fabricated as thin as 20 microns when prepared using a sacrificial aluminum substrate. We also demonstrate a technique to prepare crack-free sulfur electrodes with different types of carbons. The introduction of ISSE and the implementation on the crack free cathode side reduces or eliminates the necessity of a liquid electrolyte, allowing the diffusion of ions by taking advantage of the intercalation mechanism, this opens the possibility of extending the performance of Li-S to reasonable charge and discharge rates in a solid or hybrid solid-liquid electrolyte configuration. References (1) Fan, X.; Sun, W.; Meng, F.; Xing, A.; Liu, J. Green Energy Environ. 2018, 3 (1), 2–19. (2) Moy, D.; Narayanan, S. R. J. Electrochem. Soc. 2017, 164 (4), A560–A566. Figure 1

Achieving a Stable High Surface Excess of Glucose Oxidase on Pristine Multiwalled Carbon Nanotubes for Glucose Quantification.

In this study, glucose oxidase (GOx) immobilization onto ten different types of carbon modified GCEs and its direct electron transfer (DET) were investigated. A maximum amount of GOx immobilization (ΓGOx) of 2.9 nM/cm2 was achieved on the pristine multiwalled carbon nanotubes (PMWCNT) with high stability. Furthermore, the coefficient value for electron transfer (0.5) and the rate constant of 3.16 s-1 were measured from scan rate studies on PMWCNT/GOx. The derived electro-analytical parameters were superior in PMWCNT system than those of several CNT based nanocomposite materials published in the literature. The PMWCNT/GOx displayed a standard potential (E0') of -444 mV with perfect redox peaks, and appreciable peak separation (ΔEp) value of 22 mV in neutral electrolyte medium was noted. Glucose quantification was made using the mediator, ferrocene monocarboxylic acid (FMCA), and quantification was done with dissolved oxygen (O2) reduction caused by the glucose oxidase-mediated enzymatic catalysis of glucose. Sensor calibration results revealed a broad range from 0.2 to 5.8 mM with a lower limit of determination found to be 45 μM for glucose. A strong affinity between PMWCNT/GOx and glucose was assessed with Michaelis-Menten constant (2.24 mM). The proposed biosensor had excellent sensitivity and remained unaffected by the presence of other electroactive groups. This work demonstrates that pristine MWCNT can be used directly as an immobilization matrix for biosensing applications without cumbersome electrode preparation steps and the introduction of dopants.

Recirculating Water Treatment in Closed Hydroponic Systems: Assessment of Granular Activated Carbon and Soft Templated Mesoporous Carbon for Adsorptive Removal of Root Exudates

The present study deals with the characterization of reused nutrient solution (RNS) from a hydroponic farm (lettuce). Chemical analysis with GC-MS revealed the presence of eleven individual organic acids as a part of root exudates (acetic, acrylic, maleic, succinic, benzoic, phthalic, sebacic, myristic, palmitic, oleic and stearic acid). Based on these results, first batch tests were developed to determine the breakthrough time and the best kinetic model for adsorption of benzoic acid (as an indicator of these 11 organic acids) on two different types of carbon based adsorbents (granular activated carbon-GAC and soft templated mesoporous carbon-SMC). In order to evaluate the adsorption kinetics, four different kinetic models were fit to the experimental data. The pseudo-second-order best represented the experimental data for both adsorbents at all dosages, exhibiting high linear correlation coefficients (R2 ≥ 0.98). Second, to gain a better understanding of the adsorption efficiency during the batch experiments, several parameters were measured (i.e., COD, UV254, pH and EC) and the effect of adsorbent dosages on these parameters was studied. Third, the effect of different flow rates and bed heights on the breakthrough curve was studied during column tests. These curves were fitted to four well-known fixed-bed adsorption models, namely Thomas, Bohart−Adams, Yoon–Nelson and BDST models. The latter model was found to be most suitable (R2 ≥ 0.88) to predict the breakthrough curve for benzoic acid uptake on GAC in fixed bed column. Scale up analysis revealed that approximately 72 kg GAC is required to treat RNS during 27 days for a typical flow rate of 360 L h−1 (3200 kg L−1).

Coalescence and wetting mechanism of Al droplets on different types of carbon for developing wettable cathodes: a molecular dynamics simulation.

So far, there have been few studies on the microscopic wetting behavior of aluminum liquid on cathode surfaces, which is critical for developing wettable cathode materials. In the present study, an investigation on the coalescence and wetting mechanism of Al droplets on different carbonaceous substrates has been performed via molecular dynamics (MD) simulation for developing wettable cathodes. The growth rate of liquid bridge, the mean squared displacement, the balanced contact angle, and the time of full coalescence were calculated to describe the coalescence and wetting of the Al droplets. The results illustrate the sequence of full coalescence time for the Al droplets: DG < HCNT < VCNT ≈ AC and the corresponding balanced contact angles were 47.98°, 53.32°, 55.02°, and 63.12°, respectively. Furthermore, the presence of defects on DG will increase the time of coalescence and the contact angle but the directions of defects have little influence. The free energy analysis indicates that the defects reduce the solid-liquid interaction and the work done for removing the Al droplet from the substrates so that the wettability is weaker than that for perfect graphene, which also explains the balanced wettability of Al droplets on the other substrates. In addition, the surface roughness increases the contact angle of Al liquid on AC (from 62° to 113°-120°) and hence, the wettability is changed from good to poor. In general, our results can improve the understanding of the wetting of AC and graphene by Al liquid at the atomic level, which can provide direction and theoretical guidance for further research on wettable cathodes.

Carbon Containing Material in Non-Woven Fabrics for Thermoinsulation of Winter Apparel

Nowadays different types of carbon containing fibers become more and more popular in textile. Pure carbon fibers, fibers with carbon particles, graphene and even carbon containing dyes began to apply in textile for different purposes. Fibers may contain from about 1% of black carbon for antistatic property up to 40% of graphene for special mechanical and moisture management properties. Carbon has pro and contra as thermoinsulating material. It possesses great ability to absorb heat but, at the same time, carbon is good thermoconductive material, and heat escapes quickly due to high thermal conductivity. Heat loss from human body is realized through several channels. For example, thermoconductive heat loss is only 10-15%, whereas irradiative heat loss can reach up to 80% from total heat loss value. Based on this information, we developed non-woven carbon containing compositions which is targeted for maximizing capture of outgoing irradiation heat and minimizing heat loss in thermoconductive channel. In this work, we presented result of development of different carbon containing non-woven compositions for insulation. As a result, some of our non-woven paddings with density 100 g/m2 have clothing insulation value (CLO) equal 4, which makes them close to natural down insulation. We also provided wide characterizations of non-woven samples such as stiffness, IR absorption and reflection, washing stability, analysis of economic feasibility of industrial production.