ABSTRACT Carbonaceous thin films were prepared by plasma-assisted chemical vapor deposition. Surf... more ABSTRACT Carbonaceous thin films were prepared by plasma-assisted chemical vapor deposition. Surface of resultant films were treated by NF3 plasma at room temperature. From Raman spectra, crystallinity of sample remained almost unchanged by the surface treatment. The reduction current at 0.6 V vs. Li/Li+ in the cyclic voltammograms at the 1st cycle decreased with increasing the flow rate of NF3 . This result indicates that fluorine atoms bonded to carbon atoms play an important role in decreasing the side reaction at the 1st reduction process.
Co-intercalation of alkali metals (Li, Na, K, Rb and Cs) with various organic solvents has been u... more Co-intercalation of alkali metals (Li, Na, K, Rb and Cs) with various organic solvents has been utilized for introducing nanospaces in graphite. The co-intercalation has been conducted by a solution method. Resultant products were studied by X-ray diffraction. For solvents of cyclic ethers, co-intercalation is likely to occur for heavy alkali metals of Rb and Cs. For linear ethers with one oxygen atom, binary graphite intercalation compounds (GICs) were mainly obtained, irrespective of alkali metal species. For linear ethers with two oxygen atoms, light alkali metal, in particular, Li tends to give ternary Li±solvent±GICs. From these results, it is concluded that co-intercalation is mainly in¯uenced by the interaction between alkali metals and solvents and by the size of solvated alkali metals.
The effects of mixed conduction on the open-circuit voltage of intermediate-temperature solid oxi... more The effects of mixed conduction on the open-circuit voltage of intermediate-temperature solid oxide fuel cells (SOFCs) based on SDC20 were studied in the temperature range of 723-973 K. Though the measured OCVs of a test cell using high activity electrodes agreed well with theoretical values calculated using the conductivity data at 973 K, they deviated from the theoretical ones at lower temperatures. The OCV was dependent on electrode activity and electrolyte thickness, and it was concluded that overpotential at the electrode/electrolyte interfaces affected the OCV because of internal short circuit. The ionic transference number of SDC 20 that is free from the effect of overpotential was obtained using a method derived by Liu et al. SDC20 exhibited high ionic transference number with suppressed electronic conduction at low temperatures with highly humidified fuel. These results indicate that the electronic conduction of SDC20 can be suppressed at intermediate temperatures with high humidification of fuel, which agreed well with the results from the theoretical consideration of the conductivity data.
Yttria-stabilized zirconia (YSZ) thin films were prepared on NiO pellets by a vapour-phase reacti... more Yttria-stabilized zirconia (YSZ) thin films were prepared on NiO pellets by a vapour-phase reaction using ZrCl4 and YCl3 as metal sources and the NiO substrate as an oxygen source for the reaction. The film obtained was cubic YSZ, and its Y2O3 content was approx. 8 mol%. The effect of the sintering temperature of NiO substrates was examined. A surface-oxidized nickel
The stability at elevated temperatures of a solid electrolyte interphase (SEI) formed on a graphi... more The stability at elevated temperatures of a solid electrolyte interphase (SEI) formed on a graphite negative electrode in lithium ion batteries was investigated by storage tests and in situ atomic force microscopy (AFM) observation. When the fully discharged graphite electrode was stored at elevated temperatures, the irreversible capacity in the following cycle increased remarkably. On the other hand, when the electrode was stored at the fully charged state at elevated temperatures, it was severely self-discharged during storage. AFM observation of the SEI layer formed on a model electrode of highly oriented pyrolytic graphite revealed two important facts on the stability of the SEI at elevated temperatures: (i) dissolution and agglomeration of the SEI layer at the discharged state and (ii) serious SEI growth at the charged state. These phenomena well explain the results of the charge and discharge tests. It was also shown that the addition of vinylene carbonate greatly improves the stability of the SEI at elevated temperatures, and gives good charge and discharge performance after storage.
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2007
Reactive ion etching (RIE) of poly-β-SiC was investigated in the NF3∕O2 mixture gas plasma. The a... more Reactive ion etching (RIE) of poly-β-SiC was investigated in the NF3∕O2 mixture gas plasma. The addition of 10% oxygen concentration to the NF3 plasma increased the etching rate to ∼80nm∕min at a total pressure of 10Pa and 997nm∕min at a total pressure of 20Pa. The ratio of increase in etching rate against that in the pure NF3 plasma was ∼43%. RIE for longer than 30min in the 90% NF3 and 10% O2 mixture gas plasma gave a much smoother surface than that etched in the pure NF3 plasma. However, the further addition of O2 decreased the etching rate. Optical-emission spectra indicated the presence of an oxygen radical, in addition to fluorine radical and molecular nitrogen cations, in the NF3∕O2 mixture gas plasma. X-ray photoemission spectroscopy analysis of the etched samples revealed that the SiO2 layer was formed on the surface at the higher O2 concentration. The role of oxygen in the NF3∕O2 mixture gas plasma was elucidated. Scanning electron microscopy observation revealed that many...
metal compounds, there have been few precise crystallo-Crystal structure of perovskite La 1؊x Sr ... more metal compounds, there have been few precise crystallo-Crystal structure of perovskite La 1؊x Sr x CoO 3 (0.0 Յ Յ Յ Յ x Յ Յ Յ Յ 0.7) graphic studies for La 1Ϫx Sr x CoO 3 , in particular, on the was precisely determined by powder X-ray Rietveld analysis, variation with Sr-doping. In order to understand the origen and its correlation with the electrical properties was discussed. of the M-I transition, it is important to clarify the correla-The space group was assigned to rhombohedral R3 ළc in the tion between the crystal structure and electric conductivity. range 0.0 Յ Յ Յ Յ x Յ Յ Յ Յ 0.5 and to cubic Pm3m in the range 0.55 Յ Յ Յ Յ In the present work, we precisely determined the lattice x Յ Յ Յ Յ 0.7. At x ȁ 0.25 the CoO distance and CoO Co angle parameters and interatomic distances and angles of La 1Ϫx of this system showed an abrupt decrease and increase with Sr x CoO 3 using the powder X-ray Rietveld method. The increasing x, respectively, and the conductivity behavior correlation of the changes in crystallographic parameters changed from semiconducting to metallic. The abrupt changes with the electrical properties was also discussed. in crystal structure were attributed to a change in the band structure at the transition from semiconducting to metallic, that is, an increase in the overlap between the valence band 2. EXPERIMENTAL and doped hole sates.
Surface morphology changes of LiMn 2 O 4 thin film positive electrodes in lithium-ion batteries a... more Surface morphology changes of LiMn 2 O 4 thin film positive electrodes in lithium-ion batteries after repeated potential cycling or storage at elevated temperatures were observed by in situ atomic force microscopy (AFM) to elucidate the origen of capacity fading of LiMn 2 O 4. After repeated potential cycling in the overall potential range from 3.50 to 4.30 V at elevated temperatures, the entire thin film surface was covered with small round-shaped particles accompanied by capacity fading of the electrode, while no significant changes were observed at 25 • C. The discharge capacity decreased more significantly when cycled in the lower potential range (3.81-4.07 V) than when cycled in the higher potential range (4.04-4.30 V). After storage at elevated temperatures at a depth of discharge (DOD) of 75%, which is located in the lower potential range, similar surface morphology changes were observed. In addition, discharge capacity markedly decreased, and the crystallinity of the LiMn 2 O 4 thin film was lowered after storage. Hence, the observed changes in morphology at elevated temperatures are closely related to capacity fading of the LiMn 2 O 4 thin film. The loss of crystallinity was caused by the formation of small particles on the LiMn 2 O 4 surface, which would be accelerated on the LiMn 2 O 4 surface in contact with an electrolyte solution through some kind of dissolution/precipitation reaction.
An in situ electrochemical atomic force microscopy (AFM) observation of a composite graphite elec... more An in situ electrochemical atomic force microscopy (AFM) observation of a composite graphite electrode surface was performed in 1 mol dm À3 LiClO 4 dissolved in a mixture of ethylene carbonate ðECÞ þ diethyl carbonate (DEC), and propylene carbonate (PC) to show the applicability of scanning probe microscopy (SPM) to studies using composite graphite electrodes. In EC þ DEC, three kinds of morphological changes (curling, swelling, and exfoliation) in the vicinity of the particle edges were observed in the potential range of 0.8-1.4 V versus Li þ /Li. These morphological changes were caused by the intercalation of solvated lithium ions and their subsequent decomposition between graphene layers. On the other hand, vigorous exfoliation and rupturing of graphene layers of the graphite particles were observed at 0.9 V in PC. In addition, deterioration by the formation of holes in the composite graphite electrode was observed in PC, which is attributable to gas evolution upon decomposition of PC molecules.
The mechanism for the formation of alkyl dicarbonates in Li-ion cells was investigated. Alkyl dic... more The mechanism for the formation of alkyl dicarbonates in Li-ion cells was investigated. Alkyl dicarbonates are formed in graphite half-cells at 1.5 V versus Li/Li+ or lower, and its concentration increased with lowering charging voltage. The results of the storage tests of ...
Highly crystalline nano-sized lithium manganese oxide particles were fabricated by spray pyrolysi... more Highly crystalline nano-sized lithium manganese oxide particles were fabricated by spray pyrolysis. The resultant particles had well-developed facet planes in a transmission electron microscopy (TEM) image and electron diffraction pattern from a single particle also showed clear diffraction spots, indicating that the prepared particles were highly crystalline. The mean crystallite size estimated from X-ray diffraction peaks was ca. 18 nm, which was in good agreement with the diameter of the particles observed in the TEM image. These particles were gathered on platinum mesh and their electrochemical properties were investigated. The mean crystallite size increased with an increase in annealing temperature, which influenced the electrochemical lithium insertion/extraction properties of the particles. In particular, samples annealed at 773 K showed different kinds of lithium extraction/insertion properties in the cyclic voltammogram (CV), and only a couple of broad redox peaks were observed at around 0.8 V (versus Ag/AgCl) between 0.4 and 1.0 V. It is suggested that lithium distribute randomly in the sample annealed at 773 K sample due to the effects of grain boundaries, which resulted in different kinds of phase transition reactions.
The autoignition and low pressure combustion characteristics of five candidate polysulfide (LP-33... more The autoignition and low pressure combustion characteristics of five candidate polysulfide (LP-33) based ramjet solid fuel formulations are evaluated using pyrolysis-gas chromatography mass spectroscopy and a subscale pipe combustor. The polysulfide based fuels are oxidatively cured using p-quinone dioxime and manganese dioxide. The fuel formulations differ by the amount of elemental sulfur that is added to alter the decomposition temperature, mass burning rate, and to modify the mass fraction of low ignition temperature sulfur based decomposition gasses. The objectives of this research are to demonstrate that the autoignition temperature and the mass regression rate of the candidate fuels can be tailored as function of the sulfur doping fraction. The results of the analysis show that the mass fraction of low autoignition temperature decomposition gasses that include carbon disulfide and hydrogen disulfide increase as the mass fraction of elemental sulfur increases in the fuel formulation. Pipe combustor test results demonstrate repeatable autoignition temperatures less than 400 °C at ambient pressure for all formulations. The results also show that the primary effect of sulfur doping is to lower the mass burning rate of the fuel in direct correlation to the Shore-A hardness of the material which increases the time to ignition with no appreciable change to the mean autoignition temperature. Published by Elsevier Inc. on behalf of The Combustion Institute.
Journal of Polymer Science Part A: Polymer Chemistry, 1996
Fluorocarbon polymer films were prepared by plasma polymerization using nitrogen trifluoride (NF,... more Fluorocarbon polymer films were prepared by plasma polymerization using nitrogen trifluoride (NF,) and propylene as starting materials. To improve their adhesiveness to substrates, a novel functionally gradient film in which the content of fluorine decreased continuously from the surface to the interior was prepared by changing source gas composition during deposition. This film had a smooth and pinhole-free surface, and had a high contact angle (110') for water drop. In addition, it showed good adhesion to a glass substrate.
ABSTRACT Transport phenomena of aniline through Na[sup +]-, K[sup +]-, and Cs[sup +]-form of a pe... more ABSTRACT Transport phenomena of aniline through Na[sup +]-, K[sup +]-, and Cs[sup +]-form of a perfluorosulfonate ion-exchange membrane, Nafion 117, under a flow of dc current, electrotransportation, were investigated. In each form, an increase in transport number of anilinium cation was observed in the current density range from 0.3 to 1.3 mA cm[sup [minus]2]. The transport number of the anilinium cation in Cs[sup +]-form was larger than that expected from the concentration and diffusion coefficient of the anilinium cation in Cs[sup +]-form Nafion. These aniline transport phenomena may be attributable to a structural change of Nafion or a decrease in hydrophobic interaction between the anilinium cation and Nafion caused by the flow of dc current.
ABSTRACT Carbonaceous thin films were prepared by plasma-assisted chemical vapor deposition. Surf... more ABSTRACT Carbonaceous thin films were prepared by plasma-assisted chemical vapor deposition. Surface of resultant films were treated by NF3 plasma at room temperature. From Raman spectra, crystallinity of sample remained almost unchanged by the surface treatment. The reduction current at 0.6 V vs. Li/Li+ in the cyclic voltammograms at the 1st cycle decreased with increasing the flow rate of NF3 . This result indicates that fluorine atoms bonded to carbon atoms play an important role in decreasing the side reaction at the 1st reduction process.
Co-intercalation of alkali metals (Li, Na, K, Rb and Cs) with various organic solvents has been u... more Co-intercalation of alkali metals (Li, Na, K, Rb and Cs) with various organic solvents has been utilized for introducing nanospaces in graphite. The co-intercalation has been conducted by a solution method. Resultant products were studied by X-ray diffraction. For solvents of cyclic ethers, co-intercalation is likely to occur for heavy alkali metals of Rb and Cs. For linear ethers with one oxygen atom, binary graphite intercalation compounds (GICs) were mainly obtained, irrespective of alkali metal species. For linear ethers with two oxygen atoms, light alkali metal, in particular, Li tends to give ternary Li±solvent±GICs. From these results, it is concluded that co-intercalation is mainly in¯uenced by the interaction between alkali metals and solvents and by the size of solvated alkali metals.
The effects of mixed conduction on the open-circuit voltage of intermediate-temperature solid oxi... more The effects of mixed conduction on the open-circuit voltage of intermediate-temperature solid oxide fuel cells (SOFCs) based on SDC20 were studied in the temperature range of 723-973 K. Though the measured OCVs of a test cell using high activity electrodes agreed well with theoretical values calculated using the conductivity data at 973 K, they deviated from the theoretical ones at lower temperatures. The OCV was dependent on electrode activity and electrolyte thickness, and it was concluded that overpotential at the electrode/electrolyte interfaces affected the OCV because of internal short circuit. The ionic transference number of SDC 20 that is free from the effect of overpotential was obtained using a method derived by Liu et al. SDC20 exhibited high ionic transference number with suppressed electronic conduction at low temperatures with highly humidified fuel. These results indicate that the electronic conduction of SDC20 can be suppressed at intermediate temperatures with high humidification of fuel, which agreed well with the results from the theoretical consideration of the conductivity data.
Yttria-stabilized zirconia (YSZ) thin films were prepared on NiO pellets by a vapour-phase reacti... more Yttria-stabilized zirconia (YSZ) thin films were prepared on NiO pellets by a vapour-phase reaction using ZrCl4 and YCl3 as metal sources and the NiO substrate as an oxygen source for the reaction. The film obtained was cubic YSZ, and its Y2O3 content was approx. 8 mol%. The effect of the sintering temperature of NiO substrates was examined. A surface-oxidized nickel
The stability at elevated temperatures of a solid electrolyte interphase (SEI) formed on a graphi... more The stability at elevated temperatures of a solid electrolyte interphase (SEI) formed on a graphite negative electrode in lithium ion batteries was investigated by storage tests and in situ atomic force microscopy (AFM) observation. When the fully discharged graphite electrode was stored at elevated temperatures, the irreversible capacity in the following cycle increased remarkably. On the other hand, when the electrode was stored at the fully charged state at elevated temperatures, it was severely self-discharged during storage. AFM observation of the SEI layer formed on a model electrode of highly oriented pyrolytic graphite revealed two important facts on the stability of the SEI at elevated temperatures: (i) dissolution and agglomeration of the SEI layer at the discharged state and (ii) serious SEI growth at the charged state. These phenomena well explain the results of the charge and discharge tests. It was also shown that the addition of vinylene carbonate greatly improves the stability of the SEI at elevated temperatures, and gives good charge and discharge performance after storage.
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2007
Reactive ion etching (RIE) of poly-β-SiC was investigated in the NF3∕O2 mixture gas plasma. The a... more Reactive ion etching (RIE) of poly-β-SiC was investigated in the NF3∕O2 mixture gas plasma. The addition of 10% oxygen concentration to the NF3 plasma increased the etching rate to ∼80nm∕min at a total pressure of 10Pa and 997nm∕min at a total pressure of 20Pa. The ratio of increase in etching rate against that in the pure NF3 plasma was ∼43%. RIE for longer than 30min in the 90% NF3 and 10% O2 mixture gas plasma gave a much smoother surface than that etched in the pure NF3 plasma. However, the further addition of O2 decreased the etching rate. Optical-emission spectra indicated the presence of an oxygen radical, in addition to fluorine radical and molecular nitrogen cations, in the NF3∕O2 mixture gas plasma. X-ray photoemission spectroscopy analysis of the etched samples revealed that the SiO2 layer was formed on the surface at the higher O2 concentration. The role of oxygen in the NF3∕O2 mixture gas plasma was elucidated. Scanning electron microscopy observation revealed that many...
metal compounds, there have been few precise crystallo-Crystal structure of perovskite La 1؊x Sr ... more metal compounds, there have been few precise crystallo-Crystal structure of perovskite La 1؊x Sr x CoO 3 (0.0 Յ Յ Յ Յ x Յ Յ Յ Յ 0.7) graphic studies for La 1Ϫx Sr x CoO 3 , in particular, on the was precisely determined by powder X-ray Rietveld analysis, variation with Sr-doping. In order to understand the origen and its correlation with the electrical properties was discussed. of the M-I transition, it is important to clarify the correla-The space group was assigned to rhombohedral R3 ළc in the tion between the crystal structure and electric conductivity. range 0.0 Յ Յ Յ Յ x Յ Յ Յ Յ 0.5 and to cubic Pm3m in the range 0.55 Յ Յ Յ Յ In the present work, we precisely determined the lattice x Յ Յ Յ Յ 0.7. At x ȁ 0.25 the CoO distance and CoO Co angle parameters and interatomic distances and angles of La 1Ϫx of this system showed an abrupt decrease and increase with Sr x CoO 3 using the powder X-ray Rietveld method. The increasing x, respectively, and the conductivity behavior correlation of the changes in crystallographic parameters changed from semiconducting to metallic. The abrupt changes with the electrical properties was also discussed. in crystal structure were attributed to a change in the band structure at the transition from semiconducting to metallic, that is, an increase in the overlap between the valence band 2. EXPERIMENTAL and doped hole sates.
Surface morphology changes of LiMn 2 O 4 thin film positive electrodes in lithium-ion batteries a... more Surface morphology changes of LiMn 2 O 4 thin film positive electrodes in lithium-ion batteries after repeated potential cycling or storage at elevated temperatures were observed by in situ atomic force microscopy (AFM) to elucidate the origen of capacity fading of LiMn 2 O 4. After repeated potential cycling in the overall potential range from 3.50 to 4.30 V at elevated temperatures, the entire thin film surface was covered with small round-shaped particles accompanied by capacity fading of the electrode, while no significant changes were observed at 25 • C. The discharge capacity decreased more significantly when cycled in the lower potential range (3.81-4.07 V) than when cycled in the higher potential range (4.04-4.30 V). After storage at elevated temperatures at a depth of discharge (DOD) of 75%, which is located in the lower potential range, similar surface morphology changes were observed. In addition, discharge capacity markedly decreased, and the crystallinity of the LiMn 2 O 4 thin film was lowered after storage. Hence, the observed changes in morphology at elevated temperatures are closely related to capacity fading of the LiMn 2 O 4 thin film. The loss of crystallinity was caused by the formation of small particles on the LiMn 2 O 4 surface, which would be accelerated on the LiMn 2 O 4 surface in contact with an electrolyte solution through some kind of dissolution/precipitation reaction.
An in situ electrochemical atomic force microscopy (AFM) observation of a composite graphite elec... more An in situ electrochemical atomic force microscopy (AFM) observation of a composite graphite electrode surface was performed in 1 mol dm À3 LiClO 4 dissolved in a mixture of ethylene carbonate ðECÞ þ diethyl carbonate (DEC), and propylene carbonate (PC) to show the applicability of scanning probe microscopy (SPM) to studies using composite graphite electrodes. In EC þ DEC, three kinds of morphological changes (curling, swelling, and exfoliation) in the vicinity of the particle edges were observed in the potential range of 0.8-1.4 V versus Li þ /Li. These morphological changes were caused by the intercalation of solvated lithium ions and their subsequent decomposition between graphene layers. On the other hand, vigorous exfoliation and rupturing of graphene layers of the graphite particles were observed at 0.9 V in PC. In addition, deterioration by the formation of holes in the composite graphite electrode was observed in PC, which is attributable to gas evolution upon decomposition of PC molecules.
The mechanism for the formation of alkyl dicarbonates in Li-ion cells was investigated. Alkyl dic... more The mechanism for the formation of alkyl dicarbonates in Li-ion cells was investigated. Alkyl dicarbonates are formed in graphite half-cells at 1.5 V versus Li/Li+ or lower, and its concentration increased with lowering charging voltage. The results of the storage tests of ...
Highly crystalline nano-sized lithium manganese oxide particles were fabricated by spray pyrolysi... more Highly crystalline nano-sized lithium manganese oxide particles were fabricated by spray pyrolysis. The resultant particles had well-developed facet planes in a transmission electron microscopy (TEM) image and electron diffraction pattern from a single particle also showed clear diffraction spots, indicating that the prepared particles were highly crystalline. The mean crystallite size estimated from X-ray diffraction peaks was ca. 18 nm, which was in good agreement with the diameter of the particles observed in the TEM image. These particles were gathered on platinum mesh and their electrochemical properties were investigated. The mean crystallite size increased with an increase in annealing temperature, which influenced the electrochemical lithium insertion/extraction properties of the particles. In particular, samples annealed at 773 K showed different kinds of lithium extraction/insertion properties in the cyclic voltammogram (CV), and only a couple of broad redox peaks were observed at around 0.8 V (versus Ag/AgCl) between 0.4 and 1.0 V. It is suggested that lithium distribute randomly in the sample annealed at 773 K sample due to the effects of grain boundaries, which resulted in different kinds of phase transition reactions.
The autoignition and low pressure combustion characteristics of five candidate polysulfide (LP-33... more The autoignition and low pressure combustion characteristics of five candidate polysulfide (LP-33) based ramjet solid fuel formulations are evaluated using pyrolysis-gas chromatography mass spectroscopy and a subscale pipe combustor. The polysulfide based fuels are oxidatively cured using p-quinone dioxime and manganese dioxide. The fuel formulations differ by the amount of elemental sulfur that is added to alter the decomposition temperature, mass burning rate, and to modify the mass fraction of low ignition temperature sulfur based decomposition gasses. The objectives of this research are to demonstrate that the autoignition temperature and the mass regression rate of the candidate fuels can be tailored as function of the sulfur doping fraction. The results of the analysis show that the mass fraction of low autoignition temperature decomposition gasses that include carbon disulfide and hydrogen disulfide increase as the mass fraction of elemental sulfur increases in the fuel formulation. Pipe combustor test results demonstrate repeatable autoignition temperatures less than 400 °C at ambient pressure for all formulations. The results also show that the primary effect of sulfur doping is to lower the mass burning rate of the fuel in direct correlation to the Shore-A hardness of the material which increases the time to ignition with no appreciable change to the mean autoignition temperature. Published by Elsevier Inc. on behalf of The Combustion Institute.
Journal of Polymer Science Part A: Polymer Chemistry, 1996
Fluorocarbon polymer films were prepared by plasma polymerization using nitrogen trifluoride (NF,... more Fluorocarbon polymer films were prepared by plasma polymerization using nitrogen trifluoride (NF,) and propylene as starting materials. To improve their adhesiveness to substrates, a novel functionally gradient film in which the content of fluorine decreased continuously from the surface to the interior was prepared by changing source gas composition during deposition. This film had a smooth and pinhole-free surface, and had a high contact angle (110') for water drop. In addition, it showed good adhesion to a glass substrate.
ABSTRACT Transport phenomena of aniline through Na[sup +]-, K[sup +]-, and Cs[sup +]-form of a pe... more ABSTRACT Transport phenomena of aniline through Na[sup +]-, K[sup +]-, and Cs[sup +]-form of a perfluorosulfonate ion-exchange membrane, Nafion 117, under a flow of dc current, electrotransportation, were investigated. In each form, an increase in transport number of anilinium cation was observed in the current density range from 0.3 to 1.3 mA cm[sup [minus]2]. The transport number of the anilinium cation in Cs[sup +]-form was larger than that expected from the concentration and diffusion coefficient of the anilinium cation in Cs[sup +]-form Nafion. These aniline transport phenomena may be attributable to a structural change of Nafion or a decrease in hydrophobic interaction between the anilinium cation and Nafion caused by the flow of dc current.
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Papers by Minoru Inaba