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Akihiko Tanioka - One of the best experts on this subject based on the ideXlab platform.

  • pvdf pmma composite nanofiber fabricated by Electrospray Deposition crystallization of pvdf induced by solvent extraction of pmma component
    Journal of Applied Polymer Science, 2009
    Co-Authors: Tetsuya Danno, Muhamad Nasir, Hidetoshi Matsumoto, Mie Minagawa, Hideo Horibe, Akihiko Tanioka
    Abstract:

    The crystallization of poly(vinylidene fluoride) (PVDF) was observed after the poly(methyl methacrylate) (PMMA) component was extracted from the PVDF/PMMA (50/50) composite nanofiber fabricated by Electrospray Deposition, even though the original composite showed a completely amorphous pattern in the wide-angle X-ray diffraction. The content of the β-crystal form in the crystalline region depended on the PVDF/PMMA composite ratios and the type of solvents used for the extraction of the PMMA component, e.g., chloroform and toluene. Thus, the content of the β-crystal form can be controlled by selecting the original PVDF/PMMA composition and the solvent used to extract the PMMA component. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

  • preparation of pvdf pmma blend nanofibers by Electrospray Deposition effects of blending ratio and humidity
    Polymer Journal, 2009
    Co-Authors: Muhamad Nasir, Hidetoshi Matsumoto, Tetsuya Danno, Mie Minagawa, Akihiko Tanioka, Hideo Horibe
    Abstract:

    Preparation of PVDF/PMMA Blend Nanofibers by Electrospray Deposition: Effects of Blending Ratio and Humidity

  • photoelectrochemical cell using dye sensitized zinc oxide nanowires grown on carbon fibers
    Applied Physics Letters, 2008
    Co-Authors: Husnu Emrah Unalan, Hidetoshi Matsumoto, Mie Minagawa, Akihiko Tanioka, Di Wei, Kenichi Suzuki, S H Dalal, Pritesh Hiralal, Shinji Imaizumi, A J Flewitt
    Abstract:

    Zinc oxide (ZnO) nanowires (NWs) grown on carbon fibers using a vapor transport and condensation approach are used as the cathode of a photoelectrochemical cell. The carbon fibers were obtained by Electrospray Deposition and take the form of a flexible carbon fabric. The ZnO NW on carbon fiber anode is combined with a “black dye” photoabsorber, an electrolyte, and a platinum (Pt) counterelectrode to complete the cell. The results show that ZnO NW and carbon fibers can be used for photoinduced charge separation/charge transport and current collection, respectively, in a photoelectrochemical cell.

  • preparation of carbon fiber fabrics from phenolic resin by Electrospray Deposition
    Polymer Journal, 2007
    Co-Authors: Kenichi Suzuki, Hidetoshi Matsumoto, Mie Minagawa, Masaru Kimura, Akihiko Tanioka
    Abstract:

    Flexible carbon fiber fabrics of 1.7 μm diameter fiber were prepared by Electrospray Deposition (ESD) from phenolic resin/poly(vinyl butyral) and successive curing and carbonization. In the present study, phenolic resin (thermostable 3-dimensional cross-linked polymer) was used for ESD and successive carbonization. The bead-free fiber was obtained by ESD from a phenolic resin solution with concentration above 55 wt %. The as-deposited fabrics, however, were very brittle. The addition of poly (vinyl butyral) (Mw=110,000) improved the dimensional stability of the as-deposited fabrics. After carbonization of the as-deposited fabrics, the flexible carbon fiber fabrics were obtained. The carbon fiber fabrics showed relatively high electrical conductivity and a large specific surface area (BET surface area = 495 m2/g). This indicates that the flexible carbon fiber fabrics are applicable not only for adsorbent and composite materials but also for materials for electronic device use.

  • molecularly imprinted nanofiber membranes from carboxylated polysulfone by Electrospray Deposition
    Macromolecular Rapid Communications, 2007
    Co-Authors: Masakazu Yoshikawa, Hidetoshi Matsumoto, Akihiko Tanioka, Koji Nakai, Michael D Guiver, Gilles P Robertson
    Abstract:

    It is demonstrated that polymeric materials can be directly converted into molecular (chiral) recognition nanofiber membranes by simultaneously applying an Electrospray Deposition and an alternative molecular imprinting during the membrane preparation process. Polysulfone with a degree of substitution of 0.88 was adopted as the candidate polymeric material for molecularly imprinted nanofiber membranes. Molecularly imprinted nanofiber membranes imprinted by Z-D-Glu recognize the D-isomer in preference to the corresponding L-isomer and vice versa. The amino acid preferentially incorporated into the membrane is selectively permeated through the membrane by using a concentration gradient as a driving force for membrane transport.

Hidetoshi Matsumoto - One of the best experts on this subject based on the ideXlab platform.

  • pvdf pmma composite nanofiber fabricated by Electrospray Deposition crystallization of pvdf induced by solvent extraction of pmma component
    Journal of Applied Polymer Science, 2009
    Co-Authors: Tetsuya Danno, Muhamad Nasir, Hidetoshi Matsumoto, Mie Minagawa, Hideo Horibe, Akihiko Tanioka
    Abstract:

    The crystallization of poly(vinylidene fluoride) (PVDF) was observed after the poly(methyl methacrylate) (PMMA) component was extracted from the PVDF/PMMA (50/50) composite nanofiber fabricated by Electrospray Deposition, even though the original composite showed a completely amorphous pattern in the wide-angle X-ray diffraction. The content of the β-crystal form in the crystalline region depended on the PVDF/PMMA composite ratios and the type of solvents used for the extraction of the PMMA component, e.g., chloroform and toluene. Thus, the content of the β-crystal form can be controlled by selecting the original PVDF/PMMA composition and the solvent used to extract the PMMA component. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

  • preparation of pvdf pmma blend nanofibers by Electrospray Deposition effects of blending ratio and humidity
    Polymer Journal, 2009
    Co-Authors: Muhamad Nasir, Hidetoshi Matsumoto, Tetsuya Danno, Mie Minagawa, Akihiko Tanioka, Hideo Horibe
    Abstract:

    Preparation of PVDF/PMMA Blend Nanofibers by Electrospray Deposition: Effects of Blending Ratio and Humidity

  • photoelectrochemical cell using dye sensitized zinc oxide nanowires grown on carbon fibers
    Applied Physics Letters, 2008
    Co-Authors: Husnu Emrah Unalan, Hidetoshi Matsumoto, Mie Minagawa, Akihiko Tanioka, Di Wei, Kenichi Suzuki, S H Dalal, Pritesh Hiralal, Shinji Imaizumi, A J Flewitt
    Abstract:

    Zinc oxide (ZnO) nanowires (NWs) grown on carbon fibers using a vapor transport and condensation approach are used as the cathode of a photoelectrochemical cell. The carbon fibers were obtained by Electrospray Deposition and take the form of a flexible carbon fabric. The ZnO NW on carbon fiber anode is combined with a “black dye” photoabsorber, an electrolyte, and a platinum (Pt) counterelectrode to complete the cell. The results show that ZnO NW and carbon fibers can be used for photoinduced charge separation/charge transport and current collection, respectively, in a photoelectrochemical cell.

  • preparation of carbon fiber fabrics from phenolic resin by Electrospray Deposition
    Polymer Journal, 2007
    Co-Authors: Kenichi Suzuki, Hidetoshi Matsumoto, Mie Minagawa, Masaru Kimura, Akihiko Tanioka
    Abstract:

    Flexible carbon fiber fabrics of 1.7 μm diameter fiber were prepared by Electrospray Deposition (ESD) from phenolic resin/poly(vinyl butyral) and successive curing and carbonization. In the present study, phenolic resin (thermostable 3-dimensional cross-linked polymer) was used for ESD and successive carbonization. The bead-free fiber was obtained by ESD from a phenolic resin solution with concentration above 55 wt %. The as-deposited fabrics, however, were very brittle. The addition of poly (vinyl butyral) (Mw=110,000) improved the dimensional stability of the as-deposited fabrics. After carbonization of the as-deposited fabrics, the flexible carbon fiber fabrics were obtained. The carbon fiber fabrics showed relatively high electrical conductivity and a large specific surface area (BET surface area = 495 m2/g). This indicates that the flexible carbon fiber fabrics are applicable not only for adsorbent and composite materials but also for materials for electronic device use.

  • molecularly imprinted nanofiber membranes from carboxylated polysulfone by Electrospray Deposition
    Macromolecular Rapid Communications, 2007
    Co-Authors: Masakazu Yoshikawa, Hidetoshi Matsumoto, Akihiko Tanioka, Koji Nakai, Michael D Guiver, Gilles P Robertson
    Abstract:

    It is demonstrated that polymeric materials can be directly converted into molecular (chiral) recognition nanofiber membranes by simultaneously applying an Electrospray Deposition and an alternative molecular imprinting during the membrane preparation process. Polysulfone with a degree of substitution of 0.88 was adopted as the candidate polymeric material for molecularly imprinted nanofiber membranes. Molecularly imprinted nanofiber membranes imprinted by Z-D-Glu recognize the D-isomer in preference to the corresponding L-isomer and vice versa. The amino acid preferentially incorporated into the membrane is selectively permeated through the membrane by using a concentration gradient as a driving force for membrane transport.

Mie Minagawa - One of the best experts on this subject based on the ideXlab platform.

  • pvdf pmma composite nanofiber fabricated by Electrospray Deposition crystallization of pvdf induced by solvent extraction of pmma component
    Journal of Applied Polymer Science, 2009
    Co-Authors: Tetsuya Danno, Muhamad Nasir, Hidetoshi Matsumoto, Mie Minagawa, Hideo Horibe, Akihiko Tanioka
    Abstract:

    The crystallization of poly(vinylidene fluoride) (PVDF) was observed after the poly(methyl methacrylate) (PMMA) component was extracted from the PVDF/PMMA (50/50) composite nanofiber fabricated by Electrospray Deposition, even though the original composite showed a completely amorphous pattern in the wide-angle X-ray diffraction. The content of the β-crystal form in the crystalline region depended on the PVDF/PMMA composite ratios and the type of solvents used for the extraction of the PMMA component, e.g., chloroform and toluene. Thus, the content of the β-crystal form can be controlled by selecting the original PVDF/PMMA composition and the solvent used to extract the PMMA component. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

  • preparation of pvdf pmma blend nanofibers by Electrospray Deposition effects of blending ratio and humidity
    Polymer Journal, 2009
    Co-Authors: Muhamad Nasir, Hidetoshi Matsumoto, Tetsuya Danno, Mie Minagawa, Akihiko Tanioka, Hideo Horibe
    Abstract:

    Preparation of PVDF/PMMA Blend Nanofibers by Electrospray Deposition: Effects of Blending Ratio and Humidity

  • photoelectrochemical cell using dye sensitized zinc oxide nanowires grown on carbon fibers
    Applied Physics Letters, 2008
    Co-Authors: Husnu Emrah Unalan, Hidetoshi Matsumoto, Mie Minagawa, Akihiko Tanioka, Di Wei, Kenichi Suzuki, S H Dalal, Pritesh Hiralal, Shinji Imaizumi, A J Flewitt
    Abstract:

    Zinc oxide (ZnO) nanowires (NWs) grown on carbon fibers using a vapor transport and condensation approach are used as the cathode of a photoelectrochemical cell. The carbon fibers were obtained by Electrospray Deposition and take the form of a flexible carbon fabric. The ZnO NW on carbon fiber anode is combined with a “black dye” photoabsorber, an electrolyte, and a platinum (Pt) counterelectrode to complete the cell. The results show that ZnO NW and carbon fibers can be used for photoinduced charge separation/charge transport and current collection, respectively, in a photoelectrochemical cell.

  • preparation of carbon fiber fabrics from phenolic resin by Electrospray Deposition
    Polymer Journal, 2007
    Co-Authors: Kenichi Suzuki, Hidetoshi Matsumoto, Mie Minagawa, Masaru Kimura, Akihiko Tanioka
    Abstract:

    Flexible carbon fiber fabrics of 1.7 μm diameter fiber were prepared by Electrospray Deposition (ESD) from phenolic resin/poly(vinyl butyral) and successive curing and carbonization. In the present study, phenolic resin (thermostable 3-dimensional cross-linked polymer) was used for ESD and successive carbonization. The bead-free fiber was obtained by ESD from a phenolic resin solution with concentration above 55 wt %. The as-deposited fabrics, however, were very brittle. The addition of poly (vinyl butyral) (Mw=110,000) improved the dimensional stability of the as-deposited fabrics. After carbonization of the as-deposited fabrics, the flexible carbon fiber fabrics were obtained. The carbon fiber fabrics showed relatively high electrical conductivity and a large specific surface area (BET surface area = 495 m2/g). This indicates that the flexible carbon fiber fabrics are applicable not only for adsorbent and composite materials but also for materials for electronic device use.

  • preparation of porous pvdf nanofiber from pvdf pvp blend by Electrospray Deposition
    Polymer Journal, 2007
    Co-Authors: Muhamad Nasir, Hidetoshi Matsumoto, Tetsuya Danno, Mie Minagawa, Akihiko Tanioka, Hideo Horibe
    Abstract:

    Nanofiber with porous structures were prepared by Electrospray Deposition (ESD) from poly(vinylidene fluoride) (PVDF)/poly(vinylpyrrolidone) (PVP) blend and subsequent selective removal of PVP. In the present work, the effect of blending ratio of PVDF/PVP on formation of the pore and crystal structure of residual PVDF fiber was investigated. The residual PVDF nanofiber showed a higher specific surface area (the highest specific surface area was 28.54 m2/g from PVDF/PVP = 67/33 w/w). The Fourier transform infrared spectroscopy and wide angle X-ray diffraction measurement also showed that selective removal of PVP enhanced the formation of β-phase crystal structure in PVDF nanofiber (β-phase content > 90%).

Yutaka Yamagata - One of the best experts on this subject based on the ideXlab platform.

  • improved power conversion efficiency of organic photovoltaic cell fabricated by Electrospray Deposition method by mixing different solvents
    Japanese Journal of Applied Physics, 2012
    Co-Authors: Takeshi Fukuda, Zentaro Honda, Norihiko Kamata, Takashi Asano, Kenji Takagi, Yutaka Yamagata, Hajime Shirai, Yusuke Tajima
    Abstract:

    A smooth surface of the poly(3-hexylthiophene) (P3HT)-doped-(6,6)-phenyl-C61-butyric acid methyl ester (PCBM) thin film was achieved by mixing different solvents for the Electrospray Deposition method. As a result, the high power-conversion efficiency (PCE) of the bulk-heterojunction organic photovoltaic cell (OPV) was comparable to that obtained in the case of the spin-coating method. By optimizing the additional solvent in o-dichlorobenzene, the P3HT/PCBM active layer with the root-means-square roughness of 2.23 nm and the PCE of 2.2% was fabricated employing acetonitrile as the additional solvent.

  • surface morphology of fluorene thin film fabricated by Electrospray Deposition technique using two organic solvents application for organic light emitting diodes
    Thin Solid Films, 2011
    Co-Authors: Takeshi Fukuda, Zentaro Honda, Norihiko Kamata, Hirotaka Asaki, Takashi Asano, Kenji Takagi, Yutaka Yamagata
    Abstract:

    Abstract We achieved the reduced the surface roughness of poly[9,9-dioctylfluorenyl-2,7-diyl]-co-1,4-benzo-(2,1,3)-thiadiazole (F8BT) thin film fabricated by the Electrospray Deposition technique, using two organic solvents. The root mean square (RMS) roughness of the F8BT thin film was reduced by the addition of dimethyl sulfoxide (DMSO) in tetrahydrofuran (THF). A minimum RMS roughness of 23 nm was obtained by optimizing the ratio of DMSO in THF. We found that the low evaporation pressure of the additional organic solvent is an important factor in attaining a smooth surface for F8BT thin film. The current density-voltage-luminance characteristics of the organic light-emitting diode was improved by reducing the surface roughness of the F8BT layer. A maximum luminance of 36.7 cd/cm 2 was obtained, and it was more than 14 times higher than the reference device fabricated by the conventional single organic solvent technique.

  • bulk heterojunction organic photovoltaic cell fabricated by the Electrospray Deposition method using mixed organic solvent
    Physica Status Solidi-rapid Research Letters, 2011
    Co-Authors: Takeshi Fukuda, Zentaro Honda, Norihiko Kamata, Takashi Asano, Kenji Takagi, Yutaka Yamagata, Keiji Ueno, Hajime Shirai, Yusuke Tajima
    Abstract:

    A high-efficiency bulk heterojunction organic photovoltaic cell (OPV) was achieved by the Electrospray Deposition method. The surface roughness of the P3HT:PCBM thin film can be reduced using the mixed solvent consisting of o-dichlorobenzene (o-DCB) and acetone. The effect of acetone concentration is related to its dielectric constant. Under an optimized concentration of acetone in o-DCB (20 vol%), the P3HT/PCBM active layer with a smooth surface can be formed, and the power conversion efficiency of the OPV was 1.9%. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

  • thin film fabrication method for organic light emitting diodes using Electrospray Deposition
    Advanced Materials, 2009
    Co-Authors: Jungmyoung Ju, Yutaka Yamagata, Toshiro Higuchi
    Abstract:

    : A new method for fabricating micropatterns of MEH-PPV thin films with surface roughnesses below 1nm is proposed, using Electrospray Deposition and a dual-solvent technique. The basic concept is that nanoparticles are deposited on the target substrate just before they become completely dry, by adding a solvent that has an evaporation speed relatively lower than that of the original solution.

  • direct and dry micro patterning of nano particles by Electrospray Deposition through a micro stencil mask
    Journal of Micromechanics and Microengineering, 2009
    Co-Authors: Yutaka Yamagata, Joonwan Kim, Beom Joon Kim, Toshiro Higuchi
    Abstract:

    A new micro-pattern formation method for thin films of organic or bio-macromolecules is proposed. The method combines an Electrospray Deposition process with a micro-fabricated stencil mask made of a silicon nitride membrane. The highest resolution of 2 µm line and space is possible using 50 nm fluorescent latex beads. The deposited nano-structure consists of clusters of particles ranging from 100 to 200 nm, which indicates that nanometer resolution is potentially achievable. The surface roughness of the deposit is about 3.6 nm on average, and thickness uniformity is about 10 nm with 76 nm film thickness over 72 µm. Size uniformity of the 5 µm dots reaches 5.2% in the coefficient of variation (CV) value. These results indicate that the resolution and uniformity of the proposed method are high. In addition, the charged particles on the micro stencil mask of electrical insulation are proved to induce a focusing effect, which suggests that the size of the deposited pattern can be smaller than the mask aperture size.

Chihwa Wang - One of the best experts on this subject based on the ideXlab platform.

  • electrical field guided Electrospray Deposition for production of gradient particle patterns
    ACS Applied Materials & Interfaces, 2018
    Co-Authors: Wei Cheng Yan, Jingwei Xie, Chihwa Wang
    Abstract:

    Our previous work demonstrated the uniform particle pattern formation on the substrates using electrical field guided Electrospray Deposition. In this work, we reported for the first time the fabri...

  • Electrical Field Guided Electrospray Deposition for Production of Gradient Particle Patterns
    2018
    Co-Authors: Wei Cheng Yan, Jingwei Xie, Chihwa Wang
    Abstract:

    Our previous work demonstrated the uniform particle pattern formation on the substrates using electrical field guided Electrospray Deposition. In this work, we reported for the first time the fabrication of gradient particle patterns on glass slides using an additional point, line, or bar electrode based on our previous Electrospray Deposition configuration. We also demonstrated that the polydimethylsiloxane (PDMS) coating could result in the formation of uniform particle patterns instead of gradient particle patterns on glass slides using the same experimental setup. Meanwhile, we investigated the effect of experimental configurations on the gradient particle pattern formation by computational simulation. The simulation results are in line with experimental observations. The formation of gradient particle patterns was ascribed to the gradient of electric field and the corresponding focusing effect. Cell patterns can be formed on the particle patterns deposited on PDMS-coated glass slides. The formed particle patterns hold great promise for high-throughput screening of biomaterial–cell interactions and sensing

  • computational and experimental studies of Electrospray Deposition process in pharmaceutical micro pattern formation
    Chemical Engineering Science, 2011
    Co-Authors: Alireza Rezvanpour, Chihwa Wang
    Abstract:

    Abstract Electrospray Deposition on a substrate through a mask is a simple (single-step) yet versatile and robust approach to generate biodegradable polymeric particle patterns. Different methods including photolithography, soft lithography and ink jetting have been employed for automated micro-pattern fabrication; however, most of them are limited to the investigation of material properties of substrates with high-cost and complex procedures. In the present work, two slightly different experimental setups were used to investigate the effect of different operational parameters in Electrospray particle Deposition on both mask and substrate. The sample consists of an aqueous solution of polymer, solvent and drug. In addition to the experimental section, a mathematical model was developed to track the particle trajectories and focusing effect in Electrospray Deposition process on the substrate. The final results confirm that the clearest particle pattern and the best focusing effect on the substrate can be achieved with long distance between the nozzle and the substrate, high voltage difference between the nozzle and the mask, short process time and low solution flow rate. On the contrary, a smooth and integrated layer on the mask can be formed with a short distance between the nozzle and substrate in which no clear pattern can be recognized. Furthermore, micro-fibers can be observed on the mask when the voltage difference between the nozzle and substrate is not high.