The effect of changing graphitization temperature toward bio-graphite from Palm Kernel Shell

This paper focuses on the relationship between heat treatment temperature toward structural transformation from amorphous carbon to highly graphitic carbon material during a production stage.The following report discusses a simple strategy to convert the palm kernel shell (PKS) into highly crystalline, high quality graphite via simple two-step process. The production involves impregnation of catalyst followed by thermal treatment. Both XRD and Raman spectroscopy allowed the observation of microstructural change of the prepared sample at temperature ranging from 1000°C to 1400°C using Ferum catalyst. From XRD pattern it can be observed that as graphitization temperature increased, the degree of graphitization also increased. Overall sample prepared at higher temperature 1400°C shows a higher degree of graphitization. PKS sample graphitized at 1400°C with the aid of Ferum catalyst shows a sharp intensified peak at 2θ = 26.5° reflecting formation of highly crystalline graphite structure. Raman spectrum also suggests similar results to XRD in which PKS-1400 shows the presence of large amount of graphitic structure as the value of (Id/Ig) ratio is lower than in other samples. HRTEM analysis visibly shows define lattice fringe, which further confirms the structural transformation from amorphous to highly ordered graphitic carbon structure. Overall, good quality graphitic carbon structure from Palm Kernel shell was succesfully synthesised via utilization of PKS, Ferum catalsyt and heat treatment method.

The Effect of Graphitization Temperature on the Composition and the Electrical Conductivity of Carbon Nanotube

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Enhancement in graphitization of coal tar pitch by functionalized carbon nanotubes

In this study, the influence of the addition of carbon nanotubes (CNTs) and carbon black (CB) on the graphitization temperature and microstructure of coal tar pitch (CTP) are investigated.

Optimization of the Amount of Zinc in the Graphitization Reaction for Radiocarbon AMS Measurements at LAC-UFF

The Radiocarbon Laboratory of the Universidade Federal Fluminense, in Brazil, has been successfully applying the zinc reduction method for graphitization of carbon samples since the development of its early protocols in 2009. Successive methodological research aiming to improve and, ultimately, optimize the precision and accuracy of our results indicates that graphitization temperatures as low as 460°C promote erratic 13C isotopic fractionation, but an approximately constant fractionation of about –5‰ is achieved at 520°C. In this work, we present isotope ratio mass spectrometry (IRMS) δ13C results for 14C reference materials graphitized at 550°C with variable amounts of zinc. Based on the results obtained from the addition of 20, 35, and 50 mg of zinc, we conclude that a slightly lower variation in 13C isotope fractionation during graphitization is obtained with less zinc. Moreover, the average isotopic fractionation is not altered by increasing the graphitization temperature from 520°C to 550°C.

Tool Wear Properties of Diamond-Cutting Ferrous Metal

The applicability of diamond cutting is greatly restricted due to the serious chemical wear for the machining of ferrous materials. The processes of diamond natural graphitization and graphitization in diamond/Fe interface were analysed by molecular dynamics (MD). Simulation proved that the graphitization temperature decreased from 5215 K of natural graphitization process to 1300 K at diamond/Fe interface, and diamond which near the Fe atoms was graphitized firstly. Diamond tool wear behavior during ordinary cutting and ultrasonic elliptical vibration cutting (UEVC) of NAK80, S136 was analysed. Results showed that the diamond tool wear decreased greatly in UEVC. MD Simulation and cutting experiments both demonstrated that lowering the temperature of the interface could effectively reduce the wear of diamond tool.

Ultra Small-Mass Graphitization by Sealed Tube Zinc Reduction Method for AMS 14C Measurements

A modified sealed tube Zn reduction method based on Khosh et al. (2010) has been developed to graphitize ultra small-mass samples ranging from 4–15 μg carbon (C) for accelerator mass spectrometry (AMS) radiocarbon measurements. In this method, the reagent TiH2 is removed from the previous method while the amounts of Zn and Fe powder remain the same. The volume of the sealed reactor is further reduced by ∼40% to ∼0.75 cm3 and the graphitization temperature is lowered to 450 °C. Graphite targets produced by this method generally yield 12C+1 currents of about 0.5 μA per 1 μg C, similar to the small mass (15–100 μg C) sealed tube Zn reduction method previously reported by Khosh et al. (2010) when measured on the same AMS system at KCCAMS, University of California, Irvine. Change of Fe powder to Sigma-Aldrich (400-mesh) has yielded further improved backgrounds over Fe powder of Alfa Aesar (325-mesh). Modern C background from combustion and graphitization is estimated to be 0.2–0.8 μg C, and dead-C background to be 0.1–0.4 μg C. The accuracy and precision of ultra small-mass samples prepared by this method are size and 14C content dependent, but is usually ±4–5% for the smallest sample size of ∼4–5 μg C with modern 14C content. AMS on-line δ13C measurement that allows for correction of both graphitization and machine-induced isotopic fractionation is the key for applying the sealed tube Zn reduction method to ultra small-mass sample graphitization.