Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal Basic Information
Journal DOI :
Korean Carbon Society
Editor in Chief :
Volume & Issues
Volume 13, Issue 4 - Oct 2012
Volume 13, Issue 3 - Jul 2012
Volume 13, Issue 2 - Apr 2012
Volume 13, Issue 1 - Jan 2012
Selecting the target year
Molecular Weight Distribution of Liquid Phase AN and Solid Phase Polymer in Precipitation Polymerization of AN By Changing Solution Composition and Temperature
Liu, Weiwei ; Zhang, Shuangkun ; Wang, Jing ; Ryu, Seung Kon ; Jin, Ri-Guang ;
Carbon letters, volume 13, issue 3, 2012, Pages 133~138
DOI : 10.5714/CL.2012.13.3.133
According to kinetic mechanisms, liquid phase polymerization and solid phase polymerization are different in acrylonitrile (AN) polymerization, and so the relationship between the contribution ratio and molecular weight distribution (MWD) was obtained through theoretic analysis. The precipitation homopolymerization of AN was carried out in a mixture solution of dimethyl sulfoxide (DMSO) and water at
-azobisisobutyronitrile as an initiator. The contribution ratio decreased and approached 0; the MWD also decreased and approached 2 with the increase of the
/DMSO ratio from 10/90 to 90/10. The experimental data were found to coincide well with the theoretical equation derived from the mechanisms.
Fabrication and Cell Culturing on Carbon Nanofibers/Nanoparticles Reinforced Membranes for Bone-Tissue Regeneration
Deng, Xu Liang ; Yang, Xiao Ping ;
Carbon letters, volume 13, issue 3, 2012, Pages 139~150
DOI : 10.5714/CL.2012.13.3.139
Poly-L-lactic acid (PLLA), PLLA/hydroxyapatite (HA), PLLA/multiwalled carbon nanotubes (MWNTs)/HA, PLLA/trifluoroethanol (TFE), PLLA/gelatin, and carbon nanofibers (CNFs)/
-tricalcium phosphate (
-TCP) composite membranes (scaffolds) were fabricated by electrospinning and their morphologies, and mechanical properties were characterized for use in bone tissue regeneration/guided tissue regeneration. MWNTs and HA nanoparticles were well distributed in the membranes and the degradation characteristics were improved. PLLA/MWNTs/HA membranes enhanced the adhesion and proliferation of periodontal ligament cells (PDLCs) by 30% and inhibited the adhesion of gingival epithelial cells by 30%. Osteoblast-like MG-63 cells on the randomly fiber oriented PLLA/TEF membrane showed irregular forms, while the cells exhibited shuttle-like shapes on the parallel fiber oriented membrane. Classical supersaturated simulated body fluids were modified by
bubbling and applied to promote the biomineralization of the PLLA/gelatin membrane; this resulted in predictions of bone bonding bioactivity of the substrates. The
-TCP membranes exhibit good biocompatibility, have an effect on PDLC growth comparable to that of pure CNF membrane, and can be applied as scaffolds for bone tissue regeneration.
Effect of the Heat Treatment Temperature on the Compressive Strength of Coal Powder Compacts
Seo, Seung-Kuk ; Roh, Jae-Seung ;
Carbon letters, volume 13, issue 3, 2012, Pages 151~156
DOI : 10.5714/CL.2012.13.3.151
This study considered the effect of the heat treatment temperature on the compressive strength of coal powder compacts affected by density, porosity, and crystallinity. Coal powder compacts were made by pressing of milled coal powder and were heat treated at 200, 400, 600, 800, and
. The density and porosity of the heat treated specimens at each temperature were measured using the Archimedes method and changes in crystallinity were analyzed using Raman spectroscopy. Increases in compressive strength at
or higher temperatures were proportionally related to increases in the density and the degree of crystallinity.
Synthesis and Electrochemical Performance of Polypyrrole-Coated Iron Oxide/Carbon Nanotube Composites
Kim, Dae-Won ; Kim, Ki-Seok ; Park, Soo-Jin ;
Carbon letters, volume 13, issue 3, 2012, Pages 157~160
DOI : 10.5714/CL.2012.13.3.157
In this work, iron oxide (
) nanoparticles were deposited on multi-walled carbon nanotubes (MWNTs) by a simple chemical coprecipitation method and
-decorated MWNTs (Fe-MWNTs)/polypyrrole (PPy) nanocomposites (Fe-MWNTs/PPy) were prepared by oxidation polymerization. The effect of the PPy on the electrochemical properties of the Fe-MWNTs was investigated. The structures characteristics and surface properties of MWNTs, Fe-MWNTs, and Fe-MWNTs/PPy were characterized by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The electrochemical performances of MWNTs, Fe-MWNTs, and Fe-MWNTs/PPy were determined by cyclic voltammetry and galvanostatic charge/discharge characteristics in a 1.0 M sodium sulfite electrolyte. The results showed that the Fe-MWNTs/PPy electrode had typical pseudo-capacitive behavior and a specific capacitance significantly greater than that of the Fe-MWNT electrode, indicating an enhanced electrochemical performance of the Fe-MWNTs/PPy due to their high electrical properties.
Effect of Inherent Anatomy of Plant Fibers on the Morphology of Carbon Synthesized from Them and Their Hydrogen Absorption Capacity
Sharon, Madhuri ; Sharon, Maheshwar ;
Carbon letters, volume 13, issue 3, 2012, Pages 161~166
DOI : 10.5714/CL.2012.13.3.161
Carbon materials were synthesized by pyrolysis from fibers of Corn-straw (Zea mays), Rice-straw (Oryza sativa), Jute-straw (Corchorus capsularis) Bamboo (Bombax bambusa), Bagass (Saccharum officinarum), Cotton (Bombax malabaricum), and Coconut (Cocos nucifera); these materials were characterized by scanning electron microscope, X-ray diffraction (XRD), and Raman spectra. All carbon materials are micro sized with large pores or channel like morphology. The unique complex spongy, porous and channel like structure of Carbon shows a lot of similarity with the original anatomy of the plant fibers used as precursor. Waxy contents like tyloses and pits present on fiber tracheids that were seen in the inherent anatomy disappear after pyrolysis and only the carbon skeleton remained; XRD analysis shows that carbon shows the development of a (002) plane, with the exception of carbon obtained from bamboo, which shows a very crystalline character. Raman studies of all carbon materials showed the presence of G- and D-bands of almost equal intensities, suggesting the presence of graphitic carbon as well as a disordered graphitic structure. Carbon materials possessing lesser density, larger surface area, more graphitic with less of an
carbon contribution, and having pore sizes around
favor hydrogen adsorption. Carbon materials synthesized from bagass meet these requirements most effectively, followed by cotton fiber, which was more effective than the carbon synthesized from the other plant fibers.
Role of Activated Carbon Modified by H
From Natural Adsorbent for Removal of Pb (II) From Aqueous Solutions
Manoochehri, Mahboobeh ; Khorsand, Ameneh ; Hashemi, Elham ;
Carbon letters, volume 13, issue 3, 2012, Pages 167~172
DOI : 10.5714/CL.2012.13.3.167
Most heavy metals are well-known toxic and carcinogenic agents and when discharged into wastewater represent a serious threat to the human population and the fauna and flora of the receiving water bodies. The present study aims to develop a procedure for Pb (II) removal. This procedure is based on using powdered activated carbon, which was prepared from walnut shells that were generated as plant wastes and modified with potassium carbonate and phosphoric acid as chemical agents. The main parameters, such as effect of pH, effect of sorbent dosage, Pb (II) concentrations, and various contact times influence the sorption process. The experimental results were analyzed by using Langmuir, Freundlich, Tempkin, and Dubinin-Radushkevich adsorption models. The kinetic study of Pb (II) on activated carbon from walnut shells was performed based on pseudo- first order and pseudo- second order equations. The data indicate that the adsorption kinetics follow the pseudo- second order rate. The procedure was successfully applied for Pb (II) removal from aqueous solutions.
Temperature and pH-Responsive Release Behavior of PVA/PAAc/PNIPAAm/MWCNTs Nanocomposite Hydrogels
Jung, Gowun ; Yun, Jumi ; Kim, Hyung-Il ;
Carbon letters, volume 13, issue 3, 2012, Pages 173~177
DOI : 10.5714/CL.2012.13.3.173
A drug delivery system (DDS) was prepared with a temperature and pH-responsive hydrogel. Poly(vinyl alcohol) (PVA)/poly(acrylic acid) (PAAc)/poly(N-isopropylacrylamide) (PNIPAAm)/multi-walled carbon nanotube (MWCNT) nanocomposites were prepared by radical polymerization for the temperature and pH-responsive hydrogels. MWCNTs were employed to improve both the thermal conductivity and mechanical properties of the PVA/PAAc/PNIPAAm/MWCNT nanocomposite hydrogels. Various amounts of MWCNTs (0, 0.5, 1 and 3 wt%) were added to the nanocomposite hydrogels. PVA/PAAc/PNIPAAm/MWCNT nanocomposite hydrogels were characterized with a scanning electron microscope. The mechanical properties were measured with a universal testing machine. Swelling and releasing properties of nanocomposite hydrogels were investigated at various temperatures and pHs. Temperature and pH-responsive release behavior was found to be dependent on the content of MWCNTs in nanocomposite hydrogels.
Improvement of Superhydrophobicity of Multi-Walled Carbon Nanotubes Produced by Fluorination
Meng, Long-Yue ; Park, Soo-Jin ;
Carbon letters, volume 13, issue 3, 2012, Pages 178~181
DOI : 10.5714/CL.2012.13.3.178
In this work, we synthesized superhydrophobic coatings by chemical surface functionalization of multi-walled carbon nanotubes (MWCNTs). This was accomplished through the radical polymerization of 3-(trimethoxysilyl) propyl methacrylate modified MWCNTs and fluoro acrylate/methyl methacrylate. The chemical compositions and microstructures of the prepared MWCNT surface were investigated using X-ray photoelectron spectroscopy, Fourier transform infrared spectrometry, and scanning electron microscopy, respectively. The wettability of the MWCNTs surface was determined through contact angle assessments in different liquids. The resulting surface exhibited a water contact angle of
, which is clear evidence of its superhydrophobicity. The 3D MWCNT networks and the low surface energy of the -C-C- and -C-F- groups play important roles in creating the superhydrophobic surface of the MWCNTs.
A New Model and Equation Derived From Surface Tension and Cohesive Energy Density of Coagulation Bath Solvents for Effective Precipitation Polymerization of Acrylonitrile
Zhou, You ; Xue, Liwei ; Yi, Kai ; Zhang, Li ; Ryu, Seung Kon ; Jin, Ri Guang ;
Carbon letters, volume 13, issue 3, 2012, Pages 182~186
DOI : 10.5714/CL.2012.13.3.182
A new model and resultant equation for the coagulation of acrylonitrile monomers in precipitation polymerization are suggested in consideration of the surface tension (
) and cohesive energy density (
). The equation was proven to be quite favorable by considering figure fittings from known surface tensions and cohesive energy densities of certain organic solvents. The relationship between scale value of surface tension (
/M) and cohesive energy density of monomers can be obtained by changing the coagulation bath component for effective precipitation polymerization of acrylonitrile in wet spinning.
Effect of Moisture Absorption on the Flexural Properties of Basalt/CNT/Epoxy Composites
Kim, Man-Tae ; Rhee, Kyong-Yop ; Kim, Hyeon-Ju ; Jung, Dong-Ho ;
Carbon letters, volume 13, issue 3, 2012, Pages 187~189
DOI : 10.5714/CL.2012.13.3.187
This study investigates the flexural properties of multi-walled carbon nanotube (MWCNT) reinforced basalt/epoxy composites under conditions with and without moisture absorption. The basalt/CNT/epoxy composites were fabricated using 1 wt% silanized MWCNTs and kept in seawater for over 4 months. The flexural properties of the moisture absorbed specimens were evaluated and compared with those of dry specimens. The flexural properties of basalt/CNT/epoxy composites were found to decrease with moisture absorption. The flexural strength and modulus of moisture absorbed specimens were 22% and 16% lower, respectively, than those of the dry specimen. Scanning electron microscope examination of the fracture surfaces revealed that the decreases of flexural properties in the moisture absorbed specimen were due to the weakening of interfacial bonding from swelling of the epoxy matrix.