研究者詳細 - 上野　智永

Light-induced levitation of ultralight carbon aerogels via temperature control 査読有り

Yanagi, R; Takemoto, R; Ono, K; Ueno, T

SCIENTIFIC REPORTS 11 巻 ( 1 ) 2021年6月

担当区分：責任著者記述言語：英語出版者・発行元：Scientific Reports

We demonstrate that ultralight carbon aerogels with skeletal densities lesser than the air density can levitate in air, based on Archimedes' principle, when heated with light. Porous materials, such as aerogels, facilitate the fabrication of materials with density less than that of air. However, their apparent density increases because of the air inside the materials, and therefore, they cannot levitate in air under normal conditions. Ultralight carbon aerogels, fabricated using carbon nanotubes, have excellent light absorption properties and can be quickly heated by a lamp owing to their small heat capacity. In this study, an ultralight carbon aerogel was heated with a halogen lamp and levitated in air by expanding the air inside as well as selectively reducing its density. We also show that the levitation of the ultralight carbon aerogel can be easily controlled by turning the lamp on and off. These findings are expected to be useful for various applications of aerogels, such as in communication and transportation through the sky.

DOI： 10.1038/s41598-021-91918-5

Color-Changing Paper: Cellulose Nanofiber Films Incorporating Mechanochromic Fluorenylidene-Acridane 査読有り

Keisuke Ogumi, Takehiro Arakawa, Bungo Okudera, Yuki Takimoto, Kohki Nagata, Kentaro Mishiba, Eiji Abe, Tomonaga Ueno, Junko Hieda, Kenji Omote, Hao-Sheng Lin, and Yutaka Matsuo

ACS Applied Engineering Materials 2 巻 ( 2 ) 頁： 397 - 403 2024年1月

Basic study on improvement of electromagnetic wave absorption for ultra-lightweight materials by insulation of CNT surface

IEICE Technical Report; IEICE Tech. Rep. 123 巻 ( 283 ) 頁： 24 - 28 2023年11月

Synergistic flame retardancy of solid acid, hindered N-alkoxy amine, and halogen compound for polypropylene 査読有り

Nakashima, E; Hosokawa, Y; Ueno, T

JOURNAL OF APPLIED POLYMER SCIENCE 140 巻 ( 41 ) 2023年11月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Applied Polymer Science

Polypropylene (PP) is a thermoplastic resin widely used in various industrial applications. However, the flammability of PP is a severe drawback that lowers operational safety. This study demonstrates the development of flame-retardant PP. The co-adding with various solid acids and a hindered N-alkoxy amine (NOR116 – Flamestab® NOR 116 FF) affects the combustion behavior of PP in a vertical flame test. The co-adding of silica alumina (SA) and NOR116 with PP promoted the melt drip, suppressed upward combustion heat, and shorter the combustion time. The decomposition products of NOR116 induced the cleavage of the main chain of PP, and it quenched the radicals on the surface of the SA particles because SA has abundant acidic sites and large pores, facilitating the adsorption of a substantial quantity of NOR116. The molecular weight of PP was controlled to 103 ~ 104 before the combustion to achieve an increase in the melt flow ability and suppress the upward combustion. Furthermore, a small amount of a halogen-based flame retardant was incorporated into the PP/SA/NOR116 sample, and the specimens could instantly self-extinguish on the gas phase by radical trap.

DOI： 10.1002/app.54511

A study on flat-plate electromagnetic field modeling of electromagnetic wave absorbing and shielding materials using CNTs 招待有り査読有り

Eiji Kurumada, Sho Muroga, Motoshi Tanaka, Tomonaga Ueno, Reo Yanagi, Kishio Hidaka, Akira Ito, Shuhei Shimada, Johta Awano, Osamu Kawasaki

IEICE Technical Report; IEICE Tech. Rep. 122 巻 ( 206 ) 頁： 68 - 71 2022年10月

Ultralight Single-Walled Carbon Nanotube Aerogels for Low-Frequency Sound Absorption 査読有り

Yanagi, R; Segi, T; Oda, R; Ueno, T

ADVANCED ENGINEERING MATERIALS 24 巻 ( 9 ) 頁： 2200357 2022年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Advanced Engineering Materials

Absorbing low-frequency sound below 1000 Hz with an ultralight material is a critical challenge. Nanofibrous sound-absorbing materials have many interfaces for air-borne sound loss. In addition, nanofibers with a high elastic modulus can increase the loss of sound propagating in the solid, enabling good, low-frequency sound absorption. Herein, a composite aerogel based on single-walled carbon nanotubes (SWCNTs) and carboxymethyl cellulose (CMC) as an ultralight material that effectively absorbs low-frequency sound is reported. This ultralight aerogel has a hierarchical porous structure composed of high-modulus SWCNT–CMC composite nanofibers. A sample with an areal density of 20 mg cm−2 (bulk density: 5 mg cm−3, thickness: 39 mm) achieves a sound-absorption coefficient of 0.44 at 500 Hz. The sound-absorption behavior is sufficiently described by the Biot–Johnson–Champoux–Allard model, indicating the significant effect of the high elastic modulus of the nanofibers on the sound-absorption performance. The article presents a new design principle for ultralight materials with low-frequency sound absorption that takes into consideration both the porous structure and the elastic modulus of the material framework.

DOI： 10.1002/adem.202200357

Carbon-nanotube-based ultralight materials for ultrabroadband electromagnetic wave shielding and absorption 査読有り

Yanagi, R; Segi, T; Ito, A; Ueno, T; Hidaka, K

JAPANESE JOURNAL OF APPLIED PHYSICS 60 巻 ( 8 ) 2021年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

In this paper, we report ultralight carbon-nanotube (CNT)-infused materials with high electromagnetic shielding and absorption performance over an ultrabroadband frequency range. By controlling the CNT content and thickness of ultralight aerogels composed of CNTs during fabrication, their electromagnetic shielding/absorbing performance can be tuned over a wide frequency range (5.6-110 GHz). Samples with 40 wt% CNTs exhibit excellent shielding performance in an intensity range of 30-90 dB in all frequency ranges. Samples with less than 5 wt% CNTs show improved electromagnetic wave absorption performance of more than 10 dB. In addition, in samples with 2 and 4 wt% CNTs, strong absorption of over 25 dB occurs at certain frequencies. These CNT aerogels, which are ultralight (bulk density: 10 mg cm-3) and exhibit good mechanical properties, are expected to become a new material for electromagnetic shielding and absorption in advanced engineering applications.

DOI： 10.35848/1347-4065/ac14a5

Elastic Recovery Properties of Ultralight Carbon Nanotube/Carboxymethyl Cellulose Composites 査読有り

Matsushima, K; Ono, K; Yanagi, R; Shioura, N; Segi, T; Ueno, T

MATERIALS 14 巻 ( 14 ) 2021年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Materials

Ultralight materials exhibit superelastic behavior depending on the selection, blending, and carbonization of the materials. Recently, ultimate low-density materials of 5 mg/cm3 or less have attracted attention for applications such as sensors, electrodes, and absorbing materials. In this study, we fabricated an ultralight material composed of single-walled carbon nanotubes (CNT) and sodium carboxymethyl cellulose (CMC), and we investigated the effect of density, composition, and weight average molecular weight of CMC on elastic recovery properties of ultralight CNT/CMC composites. Our results showed that the elastic recovery properties can be improved by reducing the density of the composite, lowering the mass ratio of CNTs, and using CMC with small molecular weight.

DOI： 10.3390/ma14144059

Image analysis of flame behavior for polyolefins and polystyrene in vertical flame test 査読有り

Hosokawa, Y; Nakashima, E; Ueno, T

JOURNAL OF APPLIED POLYMER SCIENCE 138 巻 ( 1 ) 2021年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Applied Polymer Science

Although the UL-94 vertical flame test is often used to evaluate the flammability of polymers based on ignition time and combustion duration parameters, a significant amount of information regarding the time course of combustion is difficult to analyze in detail. Herein, image analysis of the time course of the upper and lower end heights, total area, and color division of flame was performed for polyolefins and polystyrene with different molecular weights in the vertical flame test. The combustion process was classified into two stages: before and after the first drip. In the first stage, the upward spread velocity, oscillation, and color of flame were analyzed. It was assumed that the difference in the fuel production rates or thermal decomposition products depends on the molecular structure. In the second stage, the melt flowability, flame position, and combustion continuity differed vastly depending on the molecular structure or molecular weight.

DOI： 10.1002/app.49845

Fabrication and Characterization of Porous Silica/Carbon Nanotube Composite Insulation 査読有り

Shioura, N; Matsushima, K; Osato, T; Ueno, T; Isu, N; Hashimoto, T; Yana, T

MRS ADVANCES 5 巻 ( 33-34 ) 頁： 1791 - 1798 2020年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：MRS Advances

In recent years, the demand for high performance thermal insulations has increased. While foam and aerogels have been researched for high performance thermal insulation, novel material design is required for further improvement. A porous silica has been found to have the potential to form a new thermal insulation material. However, porous silica is a powder and is difficult to form the porous compact. Therefore, we propose a composite insulation of powdered porous silica (p-SiO2), carbon nanotubes (CNTs) and sodium carboxy methyl cellulose (CMC). The fine voids and bulky structure of p-SiO2 greatly suppress gas and solid heat transfer. The composite of CNT can improve the moldability and enhance the mechanical properties. The moldability of thermal insulating materials improved even with the addition of 1 wt% CNT. With the addition of 1 wt% CNT, the increase in thermal conductivity was less than 0.01 W·m-1·K-1.

DOI： 10.1557/adv.2020.252

Pattern Formation in Heterostructured Gel by the Ferrocyanide-lodate-Sulfite Reaction 査読有り

Ueno, T; Yoshida, R

JOURNAL OF PHYSICAL CHEMISTRY A 123 巻 ( 24 ) 頁： 5013 - 5018 2019年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Physical Chemistry A

Pattern formation in the reaction-diffusion systems for the ferrocyanide-iodate-sulfite reaction has been investigated. Previous studies have been conducted in a uniform medium. However, in this study, we reported the pattern formation in heterostructured gels with different network densities. The chemical states of the gel depend on the diffusivity, which in turn depends on the network density of the gel. Consequently, a pH pattern reflecting the heterostructured gel emerged. Furthermore, adjusting the condition produces novel patterns in the heterostructured gel.

DOI： 10.1021/acs.jpca.9b02264

Solution Plasma Reactions and Materials Synthesis

Panomsuwan, G; Ueno, T; Yui, H; Nakamura, J; Saito, N

MOLECULAR TECHNOLOGY, VOL 3: MATERIALS INNOVATION 頁： 137 - 172 2019年

Mechanistic aspect based on the role of reactive oxidizing species (ROS) in macroscopic level on the glycerol photooxidation over defected and defected-free TiO2 査読有り

Jedsukontorn, T; Ueno, T; Saito, N; Hunsom, M

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY 367 巻頁： 270 - 281 2018年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Photochemistry and Photobiology A: Chemistry

The activity of commercial (defected-free) TiO2 and black (defected) TiO2 photocatalysts was comparatively tested in the glycerol photooxidation reaction. The preliminary results demonstrated that similar compounds, including glyceraldehyde (GCD), dihydroxyacetone (DHA), glycolic acid (GCOA), formaldehyde (FMD) and glycolaldehyde (GCAD), were generated from the photocatalytic oxidation of glycerol via both photocatalysts, but they differed in their yields. The black TiO2 exhibited a higher photocatalytic activity to convert glycerol than the commercial TiO2, due to the presence of some defective structure and its low band gap energy, and also promoted the generation of GCAD as the main product. In contrast, the commercial TiO2 promoted the formation of GCD as the major product. The principle reactive oxidizing species (ROS) contributing for glycerol conversion via black TiO2 can be ranked in the order of O2•->O12>OHb•>h+/OHs•>h+. The dominate ROS related to the conversion of glycerol to GCD and DHA were O2•- and OHb•, respectively. The main ROS to alter GCD and DHA to GCAD/FMD was O2•-, while the h+ was the principle ROS to convert GCD to GCOA. Finally, the pathway of glycerol conversion and product distribution over black TiO2 via various ROS in the presence of oxygen as electron acceptor is proposed.

DOI： 10.1016/j.jphotochem.2018.08.030

Narrowing band gap energy of defective black TiO2 fabricated by solution plasma process and its photocatalytic activity on glycerol transformation

Jedsukontorn, T; Ueno, T; Saito, N; Hunsom, M

JOURNAL OF ALLOYS AND COMPOUNDS 757 巻頁： 188 - 199 2018年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Alloys and Compounds

Defective black titania (TiO2) was synthesized by the solution plasma technique at ambient temperature and pressure. The effects of the electrolyte solution medium type (KCl and HNO3) and concentration (0.3 and 3.0 mM) as well as the plasma discharge time (1–4 h) with a Ti electrode were investigated. The 3.0 mM HNO3 solution provided the highest energy per second discharging into the plasma, resulting in both a high synthesis rate of black TiO2 and a high degree of defective structures, as monitored in terms of the Ti3+/Ti4+ ratio, which can shorten the band gap energy (Eg) of the obtained black TiO2. A long plasma discharge time (4 h) induced the formation of large particles of black TiO2, which appeared as a highly defective structure. Overall, the black TiO2 prepared by discharged plasma for 4 h in 3.0 mM HNO3 solution (BTN-304) provided the highest photocatalytic activity for glycerol conversion (58.49% at 24 h) and 4.85, 3.32, 2.11, 2.15, 39.15 and 26.61% yield of glyceraldehyde, dihydroxyacetone, hydroxypyruvic acid, glycolic acid, glycolaldehyde and formaldehyde, respectively. Pathway of glycerol conversion and product distribution over black TiO2 was attempted to propose. Finally, the reusability of the best black TiO2 was explored.

DOI： 10.1016/j.jallcom.2018.05.046

In vitro cytotoxicity of carbon black nanoparticles synthesized from solution plasma on human lung fibroblast cells

Panomsuwan, G; Chokradjaroen, C; Rujiravanit, R; Ueno, T; Saito, N

JAPANESE JOURNAL OF APPLIED PHYSICS 57 巻 ( 1 ) 2018年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

Carbon black nanoparticles (CB-NPs) have been synthesized from liquid benzene by a solution plasma method at room temperature and atmospheric pressure. The morphological observation by scanning electron microscopy revealed the agglomeration of aggregated fine particles. The synthesized CB-NPs were predominantly amorphous as confirmed by X-ray diffraction. The in vitro cytotoxicity of CB-NPs on the human lung fibroblast (MRC-5) cell line was assessed by the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and systematically compared with those of two types of commercial carbon blacks (i.e., Vulcan XC-72 and Ketjenblack EC-600JD). Cell viabilities were studied at different concentrations of 32.5, 65, 125, and 250 μg/mL. It was found that the CB-NPs derived from solution plasma exhibited a lower cytotoxicity on the MRC-5 cells than the other two comparative carbon blacks. The viability of MRC-5 cells exposed to CB-NPs remained higher than 90% even at a high concentration of 250 μg/mL. This result preliminarily confirmed the biosafety and potential use of CB-NPs in the field of biological applications.

DOI： 10.7567/JJAP.57.0102BG

Solution Plasma Process-Derived Defect-Induced Heterophase Anatase/Brookite TiO2 Nanocrystals for Enhanced Gaseous Photocatalytic Performance

Pitchaimuthu, S; Honda, K; Suzuki, S; Naito, A; Suzuki, N; Katsumata, K; Nakata, K; Ishida, N; Kitamura, N; Idemoto, Y; Kondo, T; Yuasa, M; Takai, O; Ueno, T; Saito, N; Fujishima, A; Terashima, C

ACS OMEGA 3 巻 ( 1 ) 頁： 898 - 905 2018年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Omega

We report a simple room-temperature synthesis route for increasing the reactivity of a TiO2 photocatalyst using a solution plasma process (SPP). Hydrogen radicals generated from the SPP chamber interact with the TiO2 photocatalyst feedstock, transforming its crystalline phase and introducing oxygen vacancy defects. In this work, we examined a pure anatase TiO2 as a model feedstock because of its photocatalytic attributes and well-characterized properties. After the SPP treatment, the pure anatase crystalline phase was transformed to an anatase/brookite heterocrystalline phase with oxygen vacancies. Furthermore, the SPP treatment promoted the absorption of both UV and visible light by TiO2. As a result, TiO2 treated by the SPP for 3 h showed a high gaseous photocatalytic performance (91.1%) for acetaldehyde degradation to CO2 compared with the activity of untreated TiO2 (51%). The SPP-treated TiO2 was also more active than nitrogen-doped TiO2 driven by visible light (66%). The overall photocatalytic performance was related to the SPP treatment time. The SPP technique could be used to enhance the activity of readily available feedstocks with a short processing time. These results demonstrate the potential of this method for modifying narrow-band gap metal oxides, metal sulfides, and polymer composite-based catalyst materials. The modifications of these materials are not limited to photocatalysts and could be used in a wide range of energy and environment-based applications.

DOI： 10.1021/acsomega.7b01698

Facile preparation of defective black TiO2 through the solution plasma process: Effect of parametric changes for plasma discharge on its structural and optical properties

Jedsukontorn, T; Ueno, T; Saito, N; Hunsom, M

JOURNAL OF ALLOYS AND COMPOUNDS 726 巻頁： 567 - 577 2017年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Alloys and Compounds

Defective TiO2 or black TiO2 nanoparticles (NPs) are remarkably attractive for photocatalytic applications, since the defect-disordered structure crucially affects the optical properties. In this work, high visible light-active black TiO2 NPs were synthesized by an innovative solution plasma process (SPP) with a titanium (Ti) electrode in HNO3 solution. The effects of the plasma operating parameters, in terms of the pulse frequency (20–80 kHz) and pulse width (0.5–2.0 μs) under two different HNO3 concentrations (0.3 mM and 3.0 mM) on the morphology, structural and optical properties of the obtained black TiO2 NPs were explored. Increasing the pulse frequency, pulse width and concentration of HNO3 all increased the input energy per pulse and energy per second, which induced an increased volume-based particle size, synthesis rate and Ti3+/Ti4+ ratio, but decreased the rutile mass fraction, the Ti-OH/TiO ratio and the band gap energy of the obtained black TiO2 NPs. Among all the prepared black TiO2 NP samples, those prepared at a pulse frequency of 20 kHz, pulse width of 2 μs (energy input per second of 17.3 J) in 3.0 mM HNO3 exhibited the highest visible-light absorption capability (the lowest band gap energy of ∼2.44 eV). The variation in the band gap energy was more strongly dependent on the Ti3+/Ti4+ ratio than the Ti-OH/TiO ratio in the structure of black TiO2 NPs.

DOI： 10.1016/j.jallcom.2017.08.028

Simple introduction of carboxyl head group with alkyl spacer onto multiwalled carbon nanotubes by solution plasma process

Nemoto, S; Ueno, T; Watthanaphanit, A; Hieda, J; Bratescu, MA; Saito, N

JAPANESE JOURNAL OF APPLIED PHYSICS 56 巻 ( 9 ) 2017年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japanese Journal of Applied Physics

A simple method of fabricating carboxyl-terminated multiwalled carbon nanotubes (MWCNTs) with alkyl spacers was developed to improve the dispersion quality of MWCNTs in aqueous solutions using solution plasma (SP) in a 6-aminocaproic acid solution. The formation of SP in the solution led to better dispersion of MWCNTs in aqueous solutions. Fourier transform infrared spectroscopy (FT-IR) results indicate that a carboxyl group with an alkyl spacer can be introduced by SP treatment in the 6-aminocaproic acid solution. Sedimentation tests show that the SP-treated MWCNTs in the 6-aminocaproic acid solution retained their good dispersion quality in aqueous solutions of pHs 5 6 and 9. The alkyl spacer plays an important role in the preservation of dispersion states particularly at pH 6.

DOI： 10.7567/JJAP.56.096202

Solution plasma synthesis of a boron-carbon-nitrogen catalyst with a controllable bond structure

Lee, S; Heo, Y; Bratescu, MA; Ueno, T; Saito, N

PHYSICAL CHEMISTRY CHEMICAL PHYSICS 19 巻 ( 23 ) 頁： 15264 - 15272 2017年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Physical Chemistry Chemical Physics

Synthesis of boron-carbon-nitrogen (BCN) nanocarbon with a controllable bond structure for enhanced oxygen reduction reaction (ORR) activity and durability was performed using a new method of discharge in organic solution mixtures named the 'Solution Plasma Process'. Using selected precursors a new strategy for the simultaneous synthesis of nanocarbon co-doped with heteroatoms was found. The synergistic effect of N and B in an uncoupling bond state improved the formation of new active sites for the ORR performance by changing the electronic structure of the base carbon. Meanwhile, when B and N are bonded together, the BCN catalyst contributes to a reduced ORR activity by forming a balanced electronic structure in carbon. The BCN nanocarbon with an uncoupling bond state exhibits an enhanced ORR activity under alkaline conditions, with an onset potential of -0.25 V versus -0.31 V for B/N coupling and 3.43 transferred electrons during the ORR. Although the ORR activity of the B/N uncoupling nanocarbon was not as good as the typical Pt/C, the durability of this synthesized material (15.1% current decrease after 20000 s of operation) was significantly better than that of the Pt/C catalyst (61.5% current drop under the same conditions). After the durability test, the increase of the chemical states containing oxygen was higher for Pt/C than B/N uncoupling.

DOI： 10.1039/c6cp06063c

Crystallinity and surface state of cellulose in wet ball-milling process

Nemoto, S; Ueno, T; Watthanaphanit, A; Hieda, J; Saito, N

JOURNAL OF APPLIED POLYMER SCIENCE 134 巻 ( 22 ) 2017年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Applied Polymer Science

We report the effect of wet ball-milling process under mild neutral salt conditions on the alteration of crystallinity and surface state of microcrystalline cellulose (MC). The ball-milling experiments were performed when the MC was immersed in H2O, NaCl aqueous solution, and KCl aqueous solution. Two collation groups, i.e., MC immersed in H2O2 and nonimmersed MC were additionally investigated for comparison. Except when H2O2 was present, the highest decrease in the cellulose crystallinity index (CI) was observed in dilute KCl. On the other hand, the CI of wet-milled MC/NaCl was greater than that of the wet-milled MC/H2O, however, still lower than that of the non-immersed MC. XPS results showed that the carbonization progressed in dry-milled MC and wet-milled MC/NaCl surfaces. Though, the surface oxidization progressed in wet-milled MC/H2O and wet-milled MC/KCl. Lastly, the ball-milling processes in different solutions led to various decreases of the crystallinity and the surface degradation due to carbonization and/or oxidization. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44903.

DOI： 10.1002/APP.44903

New insights into vegetable oil pyrolysis by cold plasma technique

ソリューションプラズマを用いて作製した酸化亜鉛ナノ粒子の粒径に及ぼすプラズマ生成パラメータの影響査読有り

根本心平、上野智永、Anyarat Watthanaphanit、稗田純子、齋藤永宏

表面技術 68 巻 ( 3 ) 頁： 147-152 2017年

逆ミセル構造を利用するソリューションプラズマ合成ナノカーボンの比表面積制御査読有り

森下哲典,上野智永,吉田彰仁, 稗田純子, 齋藤永宏

表面技術 68 巻 ( 3 ) 頁： 153-157 2017年

Meeprasertsagool Phimpaka, Watthanaphanit Anyarat, Ueno Tomonaga, Saito Nagahiro, Reubroycharoen Prasert

2017 INTERNATIONAL CONFERENCE ON ALTERNATIVE ENERGY IN DEVELOPING COUNTRIES AND EMERGING ECONOMIES 138 巻頁： 1153 - 1158 2017年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy Procedia

Green liquid fuels are alternatively produced by pyrolysis of vegetable oil. Still, this process requires high processing temperature and high energy consumption per unit cost. Recently, solution/liquid-phase plasma (cold plasma) is the novel method to provide the direct energy at highly excited energy state. In this study, the investigation of the green fuel synthesis from vegetables oils using cold plasma was examined. The cold plasma reactor was connected to a bipolar pulsed power supply under 200 ml of palm oil, the pulse frequency adjusted from 15-45 kHz and the voltage adjusted in ranges of 1.2-1.5 kV with 40 minutes of discharge times, pulse width 2 μs, electrode distance 0.5 mm. Properties of generated plasma were investigated by optical emission spectroscopy (OES) methods. The liquid products were analysed by GC-MS. In order to identify components of the liquid product, a GC-MS chromatogram was carried out; the main peaks were oleic acid and palmitic acid. Therefore, the other peak showed which products were cracked to short-chain hydrocarbon and hexadecane was one of the compounds which were cracked in palm oil. In conclusion, the results showed that plasma has potential and enough energy to convert vegetable oils in liquid fuels at room temperature which can also provide the direct energy better than pyrolysis.

DOI： 10.1016/j.egypro.2017.10.224

Synthesis of carbon nanoparticles from used motor oil and benzene via solution plasma process

Seangarunthong N., Khongthong P., Panomsuwan G., Ueno T., Saito N., Eiad-Ua A.

Key Engineering Materials 751 KEM 巻頁： 773 - 778 2017年

記述言語：日本語出版者・発行元：Key Engineering Materials

Carbon nanoparticles (CNPs) were successfully synthesized from the mixture of used motor oil and benzene via a solution plasma process (SPP). The synthesis was achieved within a single step at room temperature and atmospheric pressure. The effects of mixing ratio between used motor oil and benzene on the physical and chemical properties of CNPs were investigated by means of field-emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Raman spectroscopy. The results revealed that there were no significant changes in morphological feature and chemical functional groups on CNPs at different mixing ratios. The CNPs exhibited the aggregates of fine particles with the diameter of about 20-30 nm. The crystallinity of CNPs was found to be slightly increased when synthesized under the presence of used motor oil, possibly due to the effect of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons in used motor oil. We expect that the conversion of used motor oil into CNPs by SPP could be another attractive way to add the value to used motor oil prior to disposing.

DOI： 10.4028/www.scientific.net/KEM.751.773