Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Nakabayashi Koji Last modified date:2022.06.15

Assistant Professor / Department of Advanced Device Materials / Institute for Materials Chemistry and Engineering

1. Andrew Chapman, Elif Ertekin, Masanobu Kubota, Akihide Nagao, Kaila Bertsch, Arnaud Macadre, Toshihiro Tsuchiyama, Takuro Masamura, Setsuo Takaki, Ryosuke Komoda, Mohsen Dadfarnia, Brian Somerday, Alexander Tsekov Staykov, Joichi Sugimura, Yoshinori Sawae, Takehiro Morita, Hiroyoshi Tanaka, Kazuyuki Yagi, Vlad Niste, Prabakaran Saravanan, Shugo Onitsuka, Ki-Seok Yoon, Seiji Ogo, Toshinori Matsushima, Ganbaatar Tumen-Ulzii, Dino Klotz, Dinh Hoa Nguyen, George Harrington, Chihaya Adachi, Hiroshige Matsumoto, Leonard Kwati, Yukina Takahashi, Nuttavut Kosem, Tatsumi Ishihara, Miho Yamauchi, Bidyut Baran Saha, Md. Amirul Islam, Jin Miyawaki Harish Sivasankaran, Masamichi Kohno, Shigenori Fujikawa, Roman Selyanchyn, Takeshi Tsuji, Yukihiro Higashi, Reiner Kirchheim, Petros Sofronis, Achieving a Carbon Neutral Future through Advanced Functional Materials and Technologies, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 10.1246/bcsj.20210323, 95, 1, 73-103, 2022.01.
2. Cui, Q., Ma, X., Nakano, K., Nakabayashi, K., Miyawaki, J., Al-Mutairi, A., Marafi, A.M.J., Al-Otaibi, A.M., Yoon, S.-H., Mochida, I., Effect of blending on hydrotreating reactivities of atmospheric residues: Synergistic effects, FUEL, 10.1016/j.fuel.2021.120429, 293, 2021.06.
3. Jiang, F., Liao, W., Ayukawa, T., Yoon, S.-H., Nakabayashi, K., Miyawaki, J., Enhanced performance and durability of composite bipolar plate with surface modification of cactus-like carbon nanofibers, JOURNAL OF POWER SOURCES, 10.1016/j.jpowsour.2020.228903, 482, 2021.01.
4. Rahmawati, F., Ridassepri, A.F., Chairunnisab,, Wijayanta, A.T., Nakabayashi, K., Miyawaki, J., Miyazaki, T., Carbon from Bagasse Activated with Water Vapor and Its Adsorption Performance for Methylene Blue, APPLIED SCIENCES-BASEL, 10.3390/app11020678, 11, 2, 2021.01.
5. Chairunnisaa, Thu, K., Miyazaki, T., Nakabayashi, K., Miyawaki, , Wij Ayanta, A.T., Rahmawati, F., Highly microporous activated carbon from acorn nutshells and its performance in water vapor adsorption, Evergreen, 8, 1, 249-254, 2021.01.
6. Fitria Rahmawati, Viona Natalia, Agung T. Wijayanta, Koji Nakabayashi, Jin Miyawaki, Siti Rondiyah, Carbon waste powder prepared from carbon rod waste of zinc-carbon batteries for methyl orange adsorption, Bulletin of Chemical Reaction Engineering & Catalysis, 10.9767/bcrec.15.1.5148.66-73, 15, 1, 66-73, 2020.04, A research on the preparation of Carbon Waste Powder, CWP, was conducted and made from carbon rod waste which was extracted from used zinc-carbon batteries. This research was an effort to over-come environmental problem caused by battery waste by converting into adsorbent for methyl orange (MO) that frequently used by textile industries. The prepared powder was then analyzed to understand its characteristic peaks, crystallinity, and to compare the properties with other carbonaceous forms, i.e. a commercial Carbon Paper (CP), and a commercial meso- carbon micro-beads (MCMB). The analysis found that CWP is dominated by graphitic carbon. An adsorption experiment was then conducted to study their adsorption ability to methyl orange solution. The result found that those three carbona-ceous materials have the ability to adsorb methyl orange with different activities. MCMB has the high-est adsorption capacity of 0.197 mg.g-1. Meanwhile, CWP and CP show adsorption capacity of 0.066 mg.g-1 and 0.062 mg.g-1, respectively. Methyl orange adsorption on CWP and CP were under second or-der, which means the adsorption could be four times faster as the MO solution doubled. Moreover, the rate constant of MO adsorption on CWP is 8×10-4 min-1, which was higher than the rate constant of MO adsorption on CP. It confirmed that the CWP can be used as a promising adsorbent for dye waste wa-ter..
7. Koji Nakabayashi, Yoshinori Matsuo, Kazuya Isomoto, Kazunari Teshima, Tsubasa Ayukawa, Hiroki Shimanoe, Takashi Mashio, Isao Mochida, Jin Miyawaki, Seong Ho Yoon, Establishment of Innovative Carbon Nanofiber Synthesis Technology Utilizing Carbon Dioxide, ACS Sustainable Chemistry and Engineering, 10.1021/acssuschemeng.9b07253, 8, 9, 3844-3852, 2020.03, The 18th century industrial revolution dramatically changed people's lives and allowed for rapid growth of the global economy. However, since that time, the mass consumption of fossil fuels has resulted in the release of large amounts of carbon dioxide (CO2) into the atmosphere, creating a greenhouse effect and global warming. In turn, global warming poses a serious threat to the workings of society. Thus, the immobilization of emitted CO2 and the development of effective CO2 utilization technologies are currently being investigated toward the development of a sustainable society. This study proposes the manufacture of carbon nanofiber (CNF) materials using CO2 gas as a carbon source. It is expected that this technology will be valuable as a means of recapturing CO2. We report herein the effects of CO2 on CNF growth using CO2 and hydrocarbon gases on simple catalytic chemical vapor deposition (CCVD) catalysts, including Fe, Ni, and Co. Four factors were examined: The effectiveness of the catalyst, the reaction temperature, the CO2 concentration, and the specific hydrocarbons supplied in the feed gas. Use of these techniques will enable one to expect (1) future utilization of exhaust gas emitted from thermal power stations and factories as a carbon source and (2) the future possibility of directly converting CO2 to CNF by utilizing the heat given off by emission from factories and other thermal power-generating facilities as a heat source in CNF synthesis, as well as the future possibility of proposing an effective CO2 utilization system that will be revolutionary in its impact..
8. Jinchang Liu, Hiroki Shimanoe, Seunghyun Ko, Hansong Lee, Chaehyun Jo, Jaewoong Lee, Seong Hwa Hong, Hyunchul Lee, Young Pyo Jeon, Koji Nakabayashi, Jin Miyawaki, Seong Ho Yoon, Highly chlorinated polyvinyl chloride as a novel precursor for fibrous carbon material, Polymers, 10.3390/polym12020328, 12, 2, 2020.02, Pure, highly chlorinated polyvinyl chloride (CPVC), with a 63 wt % of chlorine, showed a unique-thermal-pyrolytic-phenomenon that meant it could be converted to carbon material through solid-phase carbonisation rather than liquid-phase carbonisation. The CPVC began to decompose at 270 °C, with a rapid loss in mass due to dehydrochlorination and novel aromatisation and polycondensation up to 400 °C. In this study, we attempted to prepare carbon fibre (CF) without oxidative stabilisation, using the aforementioned CPVC as a novel precursor. Through the processes of solution spinning and solid-state carbonisation, the spun CPVC fibre was directly converted to CF, with a carbonisation yield of 26.2 wt %. The CPVC-derived CF exhibited a relatively smooth surface; however, it still demonstrated a low mechanical performance. This was because the spun fibre was not stretched during the heat treatment. Tensile strength, Young's modulus and elongation values of 590 ± 84 MPa, 50 ± 8 GPa, and 1.2 ± 0.2%, respectively, were obtained from the CPVC spun fibre, with an average diameter of 19.4 μm, following carbonisation at 1600 °C for 5 min..
9. Dong Yeon Ryu, Koji Nakabayashi, Takaaki Shimohara, Ueda Morio, Isao Mochida, Jin Miyawaki, Yukwon Jeon, Joo Il Park, Seong Ho Yoon, Behaviors of cellulose-based activated carbon fiber for acetaldehyde adsorption at low concentration, Applied Sciences (Switzerland), 10.3390/app10010025, 10, 1, 2020.01, The toxic nature of acetaldehyde renders its removal from a wide range of materials highly desirable. Removal of low-concentration acetaldehyde (a group 1 carcinogenic volatile organic compound) using an adsorbent of cellulose-based activated carbon fiber modified by amine functional group (A@CACF-H) is proposed, using 2 ppm of acetaldehyde balanced with N2/O2 (79/21% v/v) observed under continuous flow, with a total flow rate of 100 mL/min over 50 mg of A@CACF-H. The effective removal of the targeted acetaldehyde is achieved by introducing the functionalized amine at optimized content. The removal mechanism of A@CACF-H is elucidated using two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (2D-GC TOF-MS), indicating the efficacy of the proposed acetaldehyde removal method..
10. Özsin Gamzenur, Ayşe Eren Pütün, Koji Nakabayashi, Jin Miyawaki, Seong-Ho Yoon, Environmental-friendly production of carbon fiber from isotropic hybrid pitches synthesized from waste biomass and polystyrene with ethylene bottom oil, Journal of Cleaner Production, 10.1016/j.jclepro.2019.118025, 239, 2019.12, In this study, spinnable isotropic pitches (IPs) were produced by pyrolytic oils of biomass and polystyrene (PS) with ethylene bottom oil (EBO or pyrolysis fuel oil: PFO) through bromination/dehydrobromination reaction. To develop spinnable pitches, four different tars were produced and hybrid pitches were synthesized using different PFO blending ratios and bromine amounts. Results showed that PFO improves spinnability and pitch yield considerably. Furthermore, pitches with the same softening point (S.P.) were produced from different precursors and spinning, stabilization and carbonization were performed to produce general-performance carbon fiber (CF). In order to explain the structure-property relationship of the products, mechanical, morphological and chemical characterization were done by TOF-MS, elemental analysis, 13C-NMR and SEM-EDX. Thus, a comparison between the characteristics of CFs was made disregarding the S.P.s and more insight into the effect of EBO was gained. Mechanical properties of CFs found to be reasonable, considering typical tensile values of IP-based CFs..
11. Hiroki Shimanoe, Seunghyun Ko, Young Pyo Jeon, Koji Nakabayashi, Jin Miyawaki, Seong Ho Yoon, Shortening stabilization time using pressurized air flow in manufacturing mesophase pitch-based carbon fiber, Polymers, 10.3390/polym11121911, 11, 12, 2019.12, Oxidation-stabilization using pressurized air flows of 0.5 and 1.0 MPa could successfully shorten the total stabilization time to less than 60 min for manufacturing mesophase pitch-based carbon fibers without deteriorating mechanical performance. Notably, the carbonized fiber heat-treated at 1000 °C for 30 min, which was oxidative-stabilized at 260 °C without soaking time with a heating rate of 2.0 °C/min using 100 mL/min of pressurized air flow of 0.5 MPa (total stabilization time: 55 min), showed excellent tensile strength and Young0s modulus of 3.4 and 177 GPa, respectively, which were higher than those of carbonized fiber oxidation-stabilized at 270 °C without soaking time with a heating rate of 0.5 °C/min using 100 mL/min of atmospheric air flow (total stabilization time: 300 min). Activation energies for oxidation reactions in stabilization using pressurized air flows were much lower than those of oxidation reactions using atmospheric air flow because of the higher oxidation diffusion from the outer surface into the center part of pitch fibers for the use of the pressurized air flows of 0.5 and 1.0 MPa than the atmospheric one. The higher oxygen diffusivities resulted in a more homogeneous distribution of oxygen weight uptake across the transverse section of mesophase pitch fibers, and allowed the improvement of the mechanical properties..
12. Qingyan Cui, Xiaoliang Ma, Koji Nakabayashi, Koji Nakano, Jin Miyawaki, Adel Al-Mutairi, Abdulazeem M.J. Marafi, Ahmed M. Al-Otaibi, Seong Ho Yoon, Isao Mochida, Changes in Composition and Molecular Structures of Atmospheric Residues during Hydrotreating, Energy and Fuels, 10.1021/acs.energyfuels.9b02692, 33, 11, 10787-10794, 2019.11, Better understanding of the changes in composition and molecular structures of atmospheric residue (AR) during hydrotreating is important for improving the hydrotreating performance of AR. Hydrotreating of an AR was carried out in a series of fixed bed reactors loaded with hydrodemetallization (HDM) and hydrodesulfurization (HDS) catalysts. The AR and its products were fractionated into saturates, aromatics, resins, and asphaltenes (SARA) and analyzed by using the gel permeation chromatography with an ultraviolet detector (GPC-UV) and with an inductively coupled plasma mass spectrometer (GPC), X-ray diffraction (XRD), 13C nuclear magnetic resonance (13C NMR), and electron spin resonance (ESR). Hydrotreating not only decreased the contents of S, N, V, Ni, resins, and asphaltenes, but also changed the composition, structure, and distribution of the remaining resins and asphaltenes as well as the remaining S, N, V, and Ni compounds in AR products. Almost all metals (V and Ni) existed in both resin (47%) and asphaltene (53%) fractions of AR, whereas in the final hydrotreated product, more than 84% of the remaining metals, which are considered as the most refractory metal compounds, were in the asphaltenes, especially those with larger molecular size. The metal compounds in resins were easier to be removed. The low HDM reactivity of the remaining metal compounds can be attributed to their larger molecular size, which inhibited their approach to the active sites of the catalysts..
13. Qingyan Cui, Xiaoliang Ma, Koji Nakabayashi, Jin Miyawaki, Adel Al-Mutairi, Abdulazim M.J. Marafi, Ahmed M. Al-Otaibi, Seong Ho Yoon, Isao Mochida, Interaction of Vanadyl Complexes in Atmospheric Residue with Their Matrixes
An ESR Study in a Temperature Range up to 170 °c, Journal of Physical Chemistry C, 10.1021/acs.jpcc.9b04808, 123, 33, 20587-20593, 2019.08, It is important to understand the interaction of vanadyl complexes in atmospheric residue (AR) with their matrixes at different conditions for demetallization processes of AR and heavy oil. An ESR study in rotational mobility of vanadyl complexes in AR was conducted at a temperature range from 20 to 170 °C with and without 1-methylnaphthalene as solvent. A complete transformation of the ESR spectrum from anisotropy to isotropy was observed at a temperature of 170 °C with decreasing AR concentration in 1-methylnaphthalene from 100 to 20 wt %, which corresponds to a transformation of the vanadyl complexes from a rigid status constrained by the surrounding matrixes to a free status. Both increase in the temperature and decrease in the AR concentration are beneficial to such transformation. The study showed that dependency of the rotational mobility of vanadyl complexes on the temperature and concentration can be classified into three domains: isotropic, transitional, and anisotropic domains. In the anisotropic domain, effects of the temperature and concentration on the B parameter can be estimated quantitatively through a model with a standard error of 0.0351. According to this study, a B contour map as a function of temperature and concentration was obtained, which provides a deeper and more comprehensive insight into the constraint on the rotational mobility of vanadyl complexes by their surrounding matrixes in AR and thus is useful for improving the demetallization process of AR and heavy oil..
14. Yao Yu, Hyun Sig Kil, Koji Nakabayashi, Seong-Ho Yoon, Jin Miyawaki, Toward development of activated carbons with enhanced effective adsorption amount by control of activation process, 4th International Conference on Industrial, Mechanical, Electrical, and Chemical Engineering, ICIMECE 2018 4th International Conference on Industrial, Mechanical, Electrical, and Chemical Engineering, 10.1063/1.5098173, 2019.04, Pore size and pore size distribution (PSD) govern effective adsorption amount, which is one of requisite properties as adsorbents in the practical applications. Although activated carbon (AC) offers remarkably high specific surface area, tailoring its PSD according to certain application, for example, narrowing the PSD, shall further enhance its superior adsorption performances. In this study, narrow PSD was challenged by attempting two-step activation process under various conditions/mixing methods using once-activated carbon as a starting material. AC with narrow PSD was successfully obtained by both slowing the heating rate and adopting solution impregnation method for second activation of the once-activated starting sample. Such expected effect was most probably attributed to more uniform distribution of activating agent on both external and internal carbon surfaces of the microporous starting sample..
15. Jinchang Liu, Hiroki Shimanoe, Jong Eun Choi, Seunghyun Ko, Young Pyo Jeon, Koji Nakabayashi, Jin Miyawaki, Seong-Ho Yoon, Effect of the pre-treated pyrolysis fuel oil
Coal tar pitch ratio on the spinnability and oxidation properties of isotropic pitch precursors and the mechanical properties of derived carbon fibers, Carbon Letters, 10.1007/s42823-019-00020-4, 29, 2, 193-202, 2019.04, Pitch precursors affording excellent spinnability, high-level oxidation-resistance, and good carbonization yields were prepared by bromination–dehydrobromination of various ratios of pyrolyzed fuel oil and coal tar pitch. The pitches exhibited spin-nabilities that were much better than those of pitches prepared via simple distillation. A pitch prepared using a 1:2 ratio of fuel oil and coal tar pitch exhibited the best tensile strength. Pitch fibers of diameter 8.9 ± 0.1 μm were stabilized at 270 °C without soaking time after heating at a rate of 0.5 °C/min and carbonized at 1100 °C for 1 h after heating at 5 °C/min. The resulting carbon fibers exhibited a tensile strength, elongation, Young’s modulus, and average diameter of 1700 ± 170 MPa, 1.6 ± 0.1%, 106 ± 37 GPa, and 7.1 ± 0.2 μm, respectively..
16. Koji Nakabayashi, Hyeonseok Yi, Dong Yeon Ryu, Dabin Chung, Jin Miyawaki, Seong Ho Yoon, Enhancement of first cycle coulombic efficiency of hard carbon derived from Eucalyptus in a sodium ion battery, Chemistry Letters, 10.1246/cl.190230, 48, 7, 753-755, 2019.01, Hard carbon derived from green Eucalyptus trees from Ethiopia was developed to enhance 1st cycle Coulombic efficiency as the anode for SIBs. Different heat treatment temperatures were applied for preparing hard carbon from Eucalyptus wood to form suitable disordered carbon structure, interlayer space, and effective pores. Hard carbon heat-treated at 1400 °C indicated the highest electrochemical properties such as discharge capacities and 1st cycle Coulombic efficiency. Especially, hard carbons heat treated above 1200 °C indicated above 80% of 1st cycle Coulombic efficiency which is relatively high..
17. Hiroki Shimanoe, Takashi Mashio, Koji Nakabayashi, Toshinori Inoue, Maki Hamaguchi, Jin Miyawaki, Isao Mochida, Seong Ho Yoon, Manufacturing spinnable mesophase pitch using direct coal extracted fraction and its derived mesophase pitch based carbon fiber, Carbon, 10.1016/j.carbon.2019.11.082, 2019.01, Spinnable mesophase pitch with high pitch yield of more than 50 wt% was successfully prepared using direct bitumen coal extracted fraction through the three-step process of hydrogenation, N2 blowing heat treatment, and thin-layer evaporation. The prepared mesophase pitch was smoothly spun to the fibrous form and could be converted into mesophase pitch-based carbonized and graphitized fibers through the usual oxidative stabilization, carbonization, and graphitization. The prepared mesophase pitch based carbon fibers showed typical random transversal structures with mechanical performances, tensile strengths of 1.83 GPa and 3.00 GPa, Young's moduli of 133 GPa and 450 GPa, and elongation properties of 1.37% and 0.68% after heat treatments at 1000 °C for 30 min and 2800 °C for 10 min, respectively. The relatively high-molecular-weight and well-developed polynuclear aromatic molecular structure of hypercoal is the likely reason for the high mesophase pitch yield. The meaning of each preparation processes, hydrogenation, N2 blowing heat treatment and thin layered evaporation, was discussed in detail. We anticipate that the success of high-yield mesophase pitch manufacturing using hypercoal as raw material will be an important key to innovatively reduce the production cost of mesophase pitch-based carbon fiber..
18. Dong Yeon Ryu, Takaaki Shimohara, Koji Nakabayashi, Jin Miyawaki, Joo Il Park, Seong-Ho Yoon, Urea/nitric acid co-impregnated pitch-based activated carbon fiber for the effective removal of formaldehyde, Journal of Industrial and Engineering Chemistry, 10.1016/j.jiec.2019.07.036, 2019.01, Urea/nitric acid co-impregnated pitch-based activated carbon fibers (ACFs) were examined as adsorbents for the removal of low-concentration formaldehyde gas from dry and humid atmospheres. Urea, which is a harmless and environmentally friendly primary amine, was selected as an effective reagent to capture formaldehyde and nitric acid was used to promote the oxidation of formaldehyde into formic acid, which inhibits the liberation of formaldehyde even under humid atmospheres. The optimized urea/nitric acid co-impregnated ACF showed a 110-fold (0.72 mg/g to 79.28 mg/g) improvement in its formaldehyde removal capability as compared to that of pristine ACF at 40% humidity. The formaldehyde removal mechanism is proposed based on careful analysis and quantification of the inlet and outlet gases. Further, the optimized sample facilitates complete removal of formaldehyde from ambient air at humidity of 11–88% and temperatures of 3–26.9 °C over 24 h, whereas only 81.5% formaldehyde removal is achieved with pristine ACF under the same conditions..
19. Muhammad Sultan, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Hyun Sig Kil, Koji Nakabayashi, Jin Miyawaki, Seong-Ho Yoon, Adsorption of Difluoromethane (HFC-32) onto phenol resin based adsorbent
Theory and experiments, International Journal of Heat and Mass Transfer, 10.1016/j.ijheatmasstransfer.2018.07.097, 127, 348-356, 2018.12, Adsorption and desorption of difluoromethane (HFC-32) onto newly developed phenol resin based adsorbent (SAC-2) have been measured experimentally for the isotherm temperatures ranging from 30 °C to 130 °C and pressure up to 3 MPa. A magnetic suspension balance based adsorption measurement unit is used to measure adsorption uptake gravimetrically. The presented SAC-2/HFC-32 pair has adsorption uptake as high as 2.23 kgref/kgads (excess adsorption) and 2.34 kgref/kgads (absolute adsorption) at 30 °C and 1.67 MPa. To the best of our knowledge, it is the highest HFC-32 adsorption capacity onto any adsorbent available in the literature. The experimental data of adsorption/desorption isotherms show that there is no hysteresis for the studied pair. The data have been fitted with Tóth; Dubinin–Astakhov (D–A); and Guggenheim, Anderson, De-Boer (GAB) adsorption isotherm models. The parameters of adsorption isotherm models are optimized by nonlinear optimization technique. The D–A model fits the experimental data precisely as compared to other models. In addition, numerical values of isosteric heat of adsorption have also been extracted by means of Clausius–Clapeyron equation using adsorption isotherm models..
20. Qingyan Cui, Xiaoliang Ma, Koji Nakano, Koji Nakabayashi, Jin Miyawaki, Adel Al-Mutairi, Abdulazim Mj Marafi, Joo Il Park, Seong Ho Yoon, Isao Mochida, Hydrotreating Reactivities of Atmospheric Residues and Correlation with Their Composition and Properties, Energy & Fuels, 10.1021/acs.energyfuels.8b01150, 32, 6, 6726-6736, 2018.06, In order to better understand the effects of composition and properties of atmospheric residues (AR) on their reactivities for hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodevanadium (HDV), hydrodenickel (HDNi), hydrodeasphaltene (HDAsp), and hydrodeconradson-carbon-residue (HDCCR) in the hydrotreating process, analysis and characterization of three ARs (AA-AR, AB-AR, and AM-AR) from Arabia crudes were conducted, and their hydrotreating reactivities were evaluated in a pilot unit over a catalyst system at 370 °C under a H2 pressure of 13.5 MPa by comparing the conversions of the various species and their rate constants on each catalyst. The overall reactivity of various species decreases in the order of vanadium species > sulfur species ≈ asphaltenes > nickel species > Conradson carbon residue precursor > nitrogen species, regardless of the sources of the ARs. Reactivities of the three ARs in HDS, HDV, and HDAsp increase in the order of AB-AR < AA-AR < AM-AR, while reactivities of the three ARs in HDNi, HDCCR, and HDN are similar. The higher nitrogen and asphaltenes concentrations and larger density of AR have strong and negative effects on the HDS, HDV, and HDAsp reactivities but no significant effect on the HDN, HDNi, and HDCCR reactivities. The B parameter obtained from electron spin resonance analysis can be a good index to predict the HDV reactivity of AR..
21. Yuki Hirai, Koji Nakabayashi, Maya Kojima, Mahito Atobe, Retraction notice to Size-controlled spherical polymer nanoparticles
synthesis with tandem acoustic emulsification followed by soap-free emulsion polymerization and one-step fabrication of colloidal crystal films of various colors: Size-controlled spherical polymer nanoparticles: synthesis with tandem acoustic emulsification followed by soap-free emulsion polymerization and one-step fabrication of colloidal crystal films of various colors 21/6 (2014) 1921 – 1927 (Ultrasonics Sonochemistry (2014) (21)(6) (1921–1927)(S135041771300312X)(10.1016/j.ultsonch.2013.12.006)), Ultrasonics Sonochemistry, 10.1016/j.ultsonch.2018.01.011, 42, 2018.04, Available online 05-JUL-2014 This article has been retracted: please see Elsevier Policy on Article Withdrawal ( This article was retracted at the request of the Editor. Article in Ultrasonics Sonochemistry which is guilty of self-plagiarism is “Size-controlled spherical polymer nanoparticles: Synthesis with tandem acoustic emulsification followed by soap-free emulsion polymerization and one-step fabrication of colloidal crystal films of various colors” <>The above paper is essentially a duplicate of an original Article in “Size-Controlled Synthesis of Polymer Nanoparticles with Tandem Acoustic Emulsification Followed by Soap-Free Emulsion Polymerization” ACS Macro Lett., 2013, 2 (6), pp 482-484, 10.1021/mz4001817..
22. Eisaku Tanaka, Hiroyuki Tateno, Yoshimasa Matsumura, Koji Nakabayashi, Izuru Kawamura, Mahito Atobe, Electrooxidative copolymerization of 3,4-Ethylenedioxithiophene and benzene from a mixture of each monomer, Bulletin of the Chemical Society of Japan, 10.1246/bcsj.20170319, 91, 2, 141-146, 2018.01, Electrooxidative copolymerization of 3,4-ethylenedioxithiophene (EDOT) and benzene from a mixture of the monomers with concentrations of 5mM EDOT and 5M benzene produced copolymer films on an anode surface. The formation of copolymer films and characterization of their electrochemical properties was confirmed using Fourier transform infrared (FTIR) spectroscopy, ultravioletvisible absorption (UVvis) spectroscopy, energy dispersive X-ray (EDX) spectroscopy, cyclic voltammetry (CV), and solid-state carbon-13 nuclear magnetic resonance (13CNMR) spectroscopy measurements. Furthermore, the copolymerization ratio could be controlled by selection of the oxidation potential applied for copolymerization..
23. Jinchang Liu, Hiroki Shimanoe, Koji Nakabayashi, Jin Miyawaki, Jong Eun Choi, Young Pyo Jeon, Seong-Ho Yoon, Enhancing the oxidative stabilization of isotropic pitch precursors prepared through the co-carbonization of ethylene bottom oil and polyvinyl chloride, Journal of Industrial and Engineering Chemistry, 10.1016/j.jiec.2018.07.008, 2018.01, An isotropic pitch precursor for fabricating carbon fibres was prepared by co-carbonization of ethylene bottom oil (EBO) and polyvinyl chloride (PVC). Various pre-treatments of EBO and PVC, and a high heating rate of 3 °C/min with no holding time, were evaluated for their effects on the oxidative stabilization process and the mechanical stability of the resulting fibres. Our stabilization process enhanced the volatilization, oxidative reaction and decomposition properties of the precursor pitch, while the addition of PVC both decreased the onset time and accelerated the oxidative reaction. Aliphatic carbon groups played a critical role in stabilization. Microstructural characterization indicated that these were first oxidised to carbon–oxygen single bonds and then converted to carbon–oxygen double bonds. Due to the higher heating rate and lack of a holding step during processing, the resulting thermoplastic fibers did not completely convert to thermoset materials, allowing partially melted, adjacent fibres to fuse. Fiber surfaces were smooth and homogeneous. Of the various methods evaluated herein, carbon fibers derived from pressure-treated EBO and PVC exhibited the highest tensile strength. This work shows that enhancing the naphthenic component of a pitch precursor through the co-carbonization of pre-treated EBO with PVC improves the oxidative properties of the resulting carbon fibers..
24. Cui, Qingyan, Koji NAKABAYASHI, 宮脇 仁, 尹 聖昊, Ma, Xiaoliang, Marafi, Abdulazim M. J., Al-Mutairi, Adel, 持田勲, Examining the molecular entanglement between V=O complexes and their matrices in atmospheric residues by ESR, RSC ADVANCES, 7, 60, 37908-37914, 2017.11.
25. Piotr Kowalczyk, Jin Miyawaki, Yuki Azuma, Seong-Ho Yoon, Koji Nakabayashi, Piotr A. Gauden, Sylwester Furmaniak, Artur P. Terzyk, Marek Wisniewski, Jerzy Włoch, Katsumi Kaneko, Alexander V. Neimark, Molecular simulation aided nanoporous carbon design for highly efficient low-concentrated formaldehyde capture, Carbon, 10.1016/j.carbon.2017.08.024, 124, 152-160, 2017.11, Although recent experimental studies have demonstrated that doping of nanoporous carbons with nitrogen is an effective strategy for highly diluted formaldehyde capture, the impact of carbon surface chemistry and the pore size on formaldehyde capture at ∼ppm concentrations is still poorly understood and controversial. This work presents a combined theoretical and experimental study on dynamic formaldehyde adsorption on pure and oxidized nanocarbons. We find using Monte Carlo simulations and confirm experimentally that cooperative effects of pore size and oxygen surface chemistry have profound impacts on the breakthrough time of formaldehyde. Molecular modeling of formaldehyde adsorption on pure and oxidized model nanoporous carbons at ∼ppm pressures reveals that high adsorption of formaldehyde ppm concentrations in narrow ultramicropores <6 Å decorated with phenolic and carboxylic groups is correlated with long formaldehyde breakthrough times measured in the columns packed with specially prepared oxidized activated carbon fiber adsorbents with the pore size of ∼5 Å..
26. Kil, Hyun-Sig, Kim, Doo-Won, Kim, Jandee, Mochida, Isao, Koji NAKABAYASHI, 宮脇 仁, 尹 聖昊, Highly graphitized carbon from non-graphitizable raw material and its formation mechanism based on domain theory, CARBON, 10.1016/j.carbon.2017.05.086, 121, 301-308, 2017.09.
27. Cui, Qingyan, Koji NAKABAYASHI, Ma, Xiaoliang, 宮脇 仁, Al-Mutairi, Adel, Marafi, Abdulazim, Park, Joo-Il, 尹 聖昊, Mochida, Isao, Effects of Blending and Heat-Treating on Composition and Distribution of SARA Fractions of Atmospheric Residues, ENERGY & FUELS, 10.1021/acs.energyfuels.6b03275, 31, 7, 6637-6648, 2017.07.
28. Cui, Qingyan, Koji NAKABAYASHI, 宮脇 仁, 尹 聖昊, Studying Rotational Mobility of V=O Complexes in Atmospheric Residues and Their Resins and Asphaltenes by Electron Spin Resonance, ENERGY & FUELS, 10.1021/acs.energyfuels.6b03279, 31, 5, 4748-4757, 2017.05.
29. Doo Won Kim, Hyun Sig Kil, Koji Nakabayashi, Seong-Ho Yoon, Jin Miyawaki, Structural elucidation of physical and chemical activation mechanisms based on the microdomain structure model, Carbon, 10.1016/j.carbon.2016.11.082, 114, 98-105, 2017.04, Activated carbons (ACs) prepared by chemical activation commonly show higher specific surface areas and higher yields than those prepared by physical activation. In this study, the differences in the pore development mechanisms between physical and chemical activation processes for AC preparation were studied from a structural point of view, based on the microdomain structure model. Phenol resin-based spherical carbon was used as the starting material. AC preparation via potassium hydroxide (KOH) activation (chemical activation) did not induce noticeable changes in the particle or microdomain sizes, despite the abundant development of pores. On the other hand, ACs produced via steam activation (physical activation) showed remarkable reductions in both particle and microdomain sizes, depending on the activation temperature. Considering the differences in activation yield and degree of developed porosity between chemical and physical activations, we concluded that, in the case of KOH activation, pore development homogeneously progressed overall for all microdomains consisting of carbon particles without apparent morphological change; however, steam activation caused inhomogeneous gasification from the outer surface of the carbon particles and microdomains. For this reason, KOH-ACs showed higher yield and superior pore development..
30. Yuzo Ohata, Donghui Long, Wenming Qiao, Licheng Ling, Koji NAKABAYASHI, 宮脇 仁, Isao Mochida, 尹 聖昊, 1.Dimensional control of tubular-type carbon nanofibers via pyrolytic carbon coating, 1-14, 2017.03.
31. Doo-Won Kim, Hyun-Sig Kil, Koji NAKABAYASHI, 宮脇 仁, 尹 聖昊, Improvement of Electric Conductivity of Non-graphitizable Carbon Material via Breaking-down and Merging of the Microdomains, EVERGREEN Joint Journal of Novel Carbon Resource Sciences & Green Asia Strategy, 4, 2017.03.
32. Doo-Won Kim, Hyun-Sig Kil, Koji NAKABAYASHI, 宮脇 仁, 尹 聖昊, Structural elucidation of physical and chemical activation mechanisms based on the microdomain structure model, 114, 98-105, 2016.11.
33. Jianxiao Yang, Koji NAKABAYASHI, 宮脇 仁, 尹 聖昊, Preparation of isotropic spinnable pitch and carbon fiber by the bromination–dehydrobromination of biotar and ethylene bottom oil mixture, Journal of Material Science, 52, 2, 1165-1171, 2016.10.
34. Jin Miyawaki, Joonyoung Yeh, Hyun-Sig Kil, Jihn Koo Lee, Koji Nakabayashi, Isao Mochida, Seong-Ho Yoon, Influence of Pore Size and Surface Functionality of Activated Carbons on Adsorption Behaviors of Indole and Amylase, Evergreen : joint journal of Novel Carbon Resource Sciences & Green Asia Strategy, 3, 2, 17-24, 2016.09, Influence of pore size and surface functionality of activated carbons on liquid-phase molecular adsorption behaviors was carefully investigated both in terms of adsorption capacity and kinetics using indole and amylase as model adsorptive bio-materials by individual single-component experiments to improve adsorptive removal efficiency and selectivity of body wastes. Activated carbon fibers having narrow pore size of about 0.65 nm showed the highest adsorption capability of indole per unit surface area. From the point of view of the adsorption rate, however, a little bit wider micropores of about 0.70 nm considered to be preferable. It was also confirmed that a presence of oxygen-containing surface functional groups induces diffusional inhibitions of indole molecules to deeper pore spaces, giving rise to a lowering both of adsorption capacity and rate of indole. On the other hand, amylase adsorption amount was limited for microporous carbons. Therefore, as for oral applications to selectively remove the wastes in the body such as indole but not for useful molecules such as amylase, the activated carbons having abundant micropores of about 0.7 nm in size and hydrophobic surfaces were found to be suitable from the individual single-component experiments..
35. Choonghyeon Lee, Yu-Jin Han, Young Deok Seo, Koji NAKABAYASHI, 宮脇 仁, Ricardo Santamaría, Rosa Menéndez, 尹 聖昊, Jyongsik Jang, C4F8 plasma treatment as an effective route for improving rate performance of natural/synthetic graphite anodes in lithium ion batteries, Carbon, 103, 28-35, 2016.02.
36. Tomoya KUNO, Yoshimasa MATSUMURA, Koji NAKABAYASHI, Mahito ATOBE, Electroresponsive Structurally Colored Materials from a Combination of Structural and Electrochromic Color Effects, Angew. Chem. Int. Ed., 55, 2503-2506, 2016.02, Electroresponsive structurally colored materials composed of ordered arrays of polyaniline@poly(methyl methacrylate) (PANI@PMMA) core-shell nanoparticles have been successfully prepared. The core-shell nanoparticles were synthesized by deposition of PANI shells on the surfaces of the PMMA cores by the oxidative polymerization of anilinium chloride. Ordered arrays were then fabricated by using the fluidic cell method. Because the ordered arrays and the PANI shells generate structural and electrochromic colors, respectively, these core-shell colloidal crystals exhibited colors resulting from the combined effects of these materials. The crystal colors depended greatly on the size of PANI@PMMA particles and could also be varied by the application of a voltage. The electrochromic colors of these arrays were found to be quite different from those exhibited by pure PANI films prepared by electrochemical oxidation..
37. Jianxiao Yang, Koji Nakabayashi, Jin Miyawaki, Seong-Ho Yoon, Preparation of isotropic pitch-based carbon fiber using hyper coal through co-carbonation with ethylene bottom oil, Journal of Industrial and Engineering Chemistry, 10.1016/j.jiec.2015.11.026, 34, 397-404, 2016.02, A spinnable pitch was developed from the tetrahydrofuran-soluble fractions (THFS) of hyper coal (HPC) and used to prepare carbon fibers. THFS-derived pitch from bituminous coal-derived HPC showed excellent spinnability and the obtained carbon fibers had a tensile strength of over 800. MPa with a diameter of 13. μm following heat treatment at 800. °C for 5. min. Thus, HPC was shown to be a useful alternative precursor for the preparation of low-cost and general-performance carbon fibers..
38. Yu-Jin Han, Choonghyeon Lee, Young Deok Seo, Koji NAKABAYASHI, 宮脇 仁, Ricardo Santamaría, Rosa Menéndez, Jyongsik Jang, 尹 聖昊, Enhancement of the rate performance of plasma-treated platelet carbon nanofiber anodes in lithium-ion batteries, RSC Advances, 6, 4810-4817, 2016.01.
39. Byung-Jun Kim, Toru Kotegawa, Youngho Eom, Jungchul An, Ik-Pyo Hong, Osamu Kato, Koji NAKABAYASHI, 宮脇 仁, Byoung Chul Kim, 持田勲, 尹 聖昊, Enhancing the tensile strength of isotropic pitch-based carbon fibers by improving the stabilization and carbonization properties of precursor pitch, Carbon, 99, 649-657, 2015.12.
40. Hiroyuki TATENO, Yoshimasa MATSUMURA, Koji NAKABAYASHI, Hisanori SENBOKU, Mahito ATOBE, Development of a Novel Electrochemical Carboxylation System Using a Microreactor, RSC Advances, 5, 98721-98723, 2015.10.
41. Yu-Jin Han, Jandee Kim, Jae-Seong Yeo, Jung Chul An, Ik-Pyo Hong, Koji NAKABAYASHI, 宮脇 仁, Jin-Do Jung, 尹 聖昊, Coating of graphite anode with coal tar pitch as an effective precursor for enhancing the rate performance in Li-ion batteries: Effects of composition and softening points of coal tar pitch, Carbon, 94, 432-438, 2015.07.
42. Toshihiro ARAI, Hiroyuki TATENO, Koji NAKABAYASHI, Tsuneo KASHIWAGI, Mahito ATOBE, An anodic aromatic C,C cross-coupling reaction using parallel laminar flow mode in a flow microreactor , Chemical Communications, 51, 4891-4894, 2015.02.
43. Hiroyuki TATENO, Koji NAKABAYASHI, Tsuneo KASHIWAGI, Hisanori SENBOKU, Mahito ATOBE, Electrochemical fixation of CO2 to organohalides in room-temperature ionic liquids under supercritical CO2, Electrochimica Acta, 161, 212-218, 2015.01.
44. Koji NAKABAYASHI, Yuki HIRAI, Maya KOJIMA, Mahito ATOBE, Size-controlled Spherical Polymer Nanoparticles: Synthesis with Tandem Acoustic Emulsification Followed by Soap-free Emulsion Polymerization and One-step Fabrication of Colloidal Crystal Films of Various Colors, Ultrason. Sonochem. , 21巻, 1921-1927, 2014.11.
45. Koji NAKABAYASHI, Hiroyuki YANAGI, Mahito ATOBE, Preparation of W/O Nanoemulsion Using Tandem Acoustic Emulsification and Its Novel Utilization as a Medium for Phase-Transfer Catalytic Reaction, RSC Advances, 4巻, 57608-57610, 2014.10.
46. Koji NAKABAYASHI, Mahito ATOBE, Templated Electrochemical Synthesis of Conducting Polymer Nanowires in the Corresponding Monomer Nanoemulsions Prepared by Tandem Acoustic Emulsification, RSC Advances, 4巻, 22938-22940, 2014.05.
47. Koji NAKABAYASHI, Toshio FUCHIGAMI, Mahito ATOBE, Tandem Acoustic Emulsion, an Effective Tool for the Electrosynthesis of Highly Transparent and Conductive Polymer Films, Electrochim. Acta, 110, 593-598, 2013.11.
48. Koji NAKABAYASHI, Maya KOJIMA, Shinsuke INAGI, Yuki HIRAI, Mahito ATOBE, Size-Controlled Synthesis of Polymer Nanoparticles with Tandem Acoustic Emulsification Followed by Soap-Free Emulsion Polymerization, ACS Macro Lett., 2, 482-484, 2013.06.
49. Ken SAKAMOTO, Koji NAKABAYASHI, Toshio FUCHIGAMI, Mahito ATOBE, Electrochemical and Photoelectrochemical Behaviors of Polythiophene Nanowires Prepared by Templated Electrodeposition in Supercritical Fluids, Electrochemistry, 81, 328-330, 2013.05.
50. Keigo FURUTA, Hiroya KOYAMA, Seiji HONMA, Koji NAKABAYASHI, Mahito ATOBE, Morphological and Electrochemical Properties of 3,4-Substitued Polythiophene Films Prepared by Electrochemical Polymerization
, Electrochemistry, 81, 334-336, 2013.05.
51. Koji NAKABAYASHI, Fumihiro AMEMIYA, Toshio FUCHIGAMI, Kenji MACHIDA, Sekihiro TAKEDA, Kenji TAMAMITSU, Mahito ATOBE, Highly Clear and Transparent Nanoemulsion Preparation under Surfactant-Free Conditions Using Tandem Acoustic Emulsification, Chemical Communications , 47, 5765-5667, 2011.04.
52. Mahito ATOBE, Shintaro IKARI, Koji NAKABAYASHI, Fumihiro AMEMIYA, Toshio FUCHIGAMI, Electrochemical Reaction of Water-insoluble Organic Droplets in Aqueous Electrolytes Using Acoustic Emulsification, Langmuir, 26, 9111-9115, 2010.02.