In this work, standardization trends related carbon nanotubes and international standardization activities in the ISO/TC229 and IEC/TC113 were introduced. The movement toward development of carbon nanotube standard began in the nanotechnology council under the IEEE in 2005. KATS has also run the carbon nanotube standardization committee to support commercialization of product containing carbon nanotube through standards since 2004. The Korean Standards such as KSD2711, 2712, 2717 were established.
We measured the non-carbon content of single-walled carbon nanotubes (SWCNTs) in SWCNT soot using thermogravimetric analysis. The weight increased percentage by the oxidation of metal in the raw soot is well obtained by TGA graph which was confirmed with ICP-AES, XRD, and XPS. This work will be very useful for the purity precise evaluation of SWCNT with UN-vis-NIR spectroscopy.
We propose an evaluation method of the relative content of single-walled carbon nanotubes (SWCNT) in SWCNT soot synthesized by arc discharge using UV-VIS-NIR absorption spectroscopy. In this method, we consider the absorbance of semiconducting and metallic SWCNTs together to calculate the relative content of SWCNTs with respect to a highly purified reference. Our method provides the more reliable and realistic evaluation of SWCNT content with respect to the whole carbonaceous content than the previously reported method.
We measured the degree of macrodispersion of the various single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) using UV-VIS-NIR absorption spectroscopy. CNTs were dispersed with SDS of 2 wt % in deionized water using the homogenizer and then were further centrifugated at 6000 g for 10 min. The degree of macrodispersion, expressed by Dm(λ)=Aa(λ)/Ab(λ)*100 (%), where λ is the wavelength and Aa(λ) and Ab(λ) are the absorbance of the sample after and before centrifugation, respectively. In the case of MWCNTs, we evaluated the degree of macrodispersion by the average degree of macrodispersion (Dm(λ)) between 1000 and 1200 nm. The degree of macrodispersion of SWCNTs was evaluated at the wavelength in which van Hove singularity-related transition regions were excluded, i.e., the range was chosen between E11S and E22S peaks. We have estimated six samples with the same method. The standard deviation of each sample was lower than 5. Therefore, we presented a reliable evaluation method for the macrodispersion of CNTs for standardization.
In this work, the hydrogen storage behaviors of carbon nanotubes (CNTs)/metal-organic frameworks-5 (MOF-5) hybrid composites (CNTs/MOF-5) were studied. Hydrothermal synthesis of MOF-5 was conducted by conventional convection heating using 1-methyl-2-pyrrolidone (NMP) as a solvent. Morphological characteristics and average size of the CNTs/MOF-5 were also obtained using a scanning electron microscopy (SEM). The pore structure and specific surface area of the CNTs/MOF-5 were analyzed by N2/77 K adsorption isotherms. The capacity of hydrogen storage of the CNTs/MOF-5 was investigated at 298 K/100 bar. As a result, the CNTs/MOF-5 had crystalline structures which were formed by hybrid synthesis process. It was noted that the CNTs/MOF-5 can be potentially encouraging materials for hydrogen adsorption and storage applications at room temperature.
The adsorption of phenolic compound resorcinol on activated carbons prepared from Moringa oleifera (Drumstick bark) has been investigated. Activated carbon was prepared by impregnating Moringa oleifera with 50% phosphoric acid in the ratio of 1:1 and 1:2(w/w), designated as MOAC1 and MOAC2. Equilibrium and isotherm studies were carried out. The influences of variables such as contact time, initial concentration of resorcinol, carbon dosage in the solution on percentage adsorption and adsorption capacity of the bark have been analysed. The equilibration time was found to be 4 h. Kinetics of resorcinol onto activated carbons was checked for pseudo first order and pseudo second order model. It was found that the adsorption of resorcinol follows pseudo second order kinetics for both MOAC1 and MOAC2. The isotherm data were correlated with isotherm models, namely Langmuir and Freundlich. Adsorption isotherms were satisfactorily fitted by both the Langmuir and Freundlich model for MOAC1 and MOAC2.
Activated carbon (AC) is one of the most effective adsorbents for organic compounds because of their extended surface area, high adsorption capacity, microporous structure and special surface reactivity. The composites of pH-sensitive hydrogel and activated carbon were prepared in order to improve the loading capacity of drug. The pH-sensitive hydrogel matrix swelled well in the basic condition to release the drug loaded in AC. The release of drug was controlled depending on both the pH due to the ionization of the carboxylic acid group and the AC due to the surface properties.
This study aims to find a correlation between XRD and Raman result of the oxidized high modulus carbon fibers as a function of its oxidation degrees, and compare with the isotropic carbon fiber reported early. La of the high modulus carbon fiber prepared by oxidation in carbon dioxide gas have been observed using laser Raman spectroscopy. The basic structural parameters of the fibers were evaluated by XRD as well. The La of the original high modulus carbon fibers were measured to be 144 a from Raman analysis and 135 a from XRD analysis. La of the 92% oxidized fiber were 168 a by using Raman and 182 a by using XRD. There was some correlation between the La value obtained from Raman and XRD. However the La value changes of the high modulus carbon fiber through whole oxidation process showed opposite tendency compare with the isotropic carbon fiber because of the fiber structure basically.
Carbon fibers are a new breed of high-strength materials. The existence of carbon fiber came into being in 1879 when Edison took out a patent for the manufacture of carbon filaments suitable for use in electric lamps. However, it was in the early 1960s when successful commercial production was started, as the requirements of the aerospace industry for better and lightweight materials became of paramount importance. In recent decades, carbon fibers have found wide applications in commercial and civilian aircraft, along with recreational, industrial, and transportation markets as the price of carbon fiber has come down and technologies have matured. The market for carbon fiber has experienced a good growth in recent years. The growth rate for the last 23years was about 12%. The article reviewed 9,641 Korea, U.S., Japan, Europe patents issued in the carbon fibers in order to offer additional insight for researchers and companies seeking to navigate carbon fiber patent landscape. This article will provide you with all the valuable information and tools you will need to investigate your study successfully within the carbon fiber field. This article also will save you hundreds of hours of your own personal research time and will significantly benefit you in expanding your business in the carbon fiber market.