Qui Tran-Cong-Miyata Tran-Cong-Miyata - Academia.edu (original) (raw)

Papers by Qui Tran-Cong-Miyata Tran-Cong-Miyata

Macromolecular Symposia, Oct 1, 2000

Acs Symposium Series, 2003

In 1991, we editors met at a Gordon Research Conference on Oscillations and Dynamic Instabilities... more In 1991, we editors met at a Gordon Research Conference on Oscillations and Dynamic Instabilities in Chemical Systems. Of the more than 120 participants, we were the only two who were working on poly meric systems. It was our dream that some day we would hold a sym posium dedicated to nonlinear dynamics and polymers. This book is a realization of that dream. This book is based on presentations made during the symposium Nonlinear Dynamics in Polymeric Systems held at the 224th National Meeting of the American Chemical Society (ACS) in Boston, Massa chusetts on August 18-22, 2002, which was cosponsored by the ACS Divisions of Polymer Chemistry, Inc. and Physical Chemistry. More than 30 participants presented their work. This volume brings together two fields of science that have, until recently, interacted only rarely. The central role of polymer science in understanding the substances of modern life and, indeed, of life itself is obvious. Nonlinear dynamics is a newer science, but one that has afford ed important insights into phenomena in chemistry, physics, mathematics, biology, geology, and even the social sciences. Perhaps because so much of polymer science occurs in an industrial context, where nonlinear behavior such as chaos is typically seen as something to be avoided, even at the cost of suboptimal operating conditions, the amount of crossfertilization between these areas has been limited. The purpose of this volume is to bring together practitioners in both fields to discuss the progress that has been made in unveiling and exploiting the nonlinear xi

超音波エレクトロニクスの基礎と応用に関するシンポジウム(CD-ROM), 2016

IEICE Technical Report; IEICE Tech. Rep., Oct 15, 2009

超音波エレクトロニクスの基礎と応用に関するシンポジウム講演予稿集, 2012

IEICE technical report. Ultrasonics, Jul 4, 2014

超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集, Nov 5, 2015

ECS transactions, Sep 23, 2016

Performance of supercapacitors is often influenced by their internal resistance since it causes u... more Performance of supercapacitors is often influenced by their internal resistance since it causes unfavorable effects such as energy dissipation and delay of charge transport during charging/discharging. In the present study, we prepared monolithic metal nanowire array electrodes in aiming at suppressing the internal resistance of supercapacitors, and examined the influence of the defect structures present in the nanowire array electrodes. Performance of the supercapacitors was investigated by using galvanostatic charge/discharge measurement, cyclic voltammetry, and electrochemical impedance spectroscopy.

ACS Applied Materials & Interfaces, Dec 9, 2021

Patterning nanocrystals in polymer films is essential for the widespread use of nanocrystals in v... more Patterning nanocrystals in polymer films is essential for the widespread use of nanocrystals in various fields from optics to electronics; therefore, the development of patterning methods for nanocrystals is an important task. Here, we report a unique approach for patterning silver nanowires (AgNWs) using a thermodynamic driving force induced by transient concentration gradients in reaction mixtures. The procedure starts with the preparation of a photocurable monomer solution containing homogeneously dispersed AgNWs. Ultraviolet illumination through a straight-line mask reduces the polymerization rate of monomers in the masked area, decreasing the polymer concentration in comparison with that in the unmasked area. Such transient polymer concentration gradients yield imbalances in the chemical potentials of AgNWs, inducing the migration of AgNWs to form a straight-line pattern of AgNWs. The pattern of AgNWs was visualized via photoluminescence imaging under a laser scanning confocal microscope and compared with the light patterns applied to the mixture. These observations revealed that the magnitude of the AgNW migration is enhanced as the transient concentration gradient increases by thickening the mask to decrease the intensity of light passing through the mask. The structural features of the AgNW pattern were reproduced using numerical simulations based on a set of reaction-diffusion equations, which suggested the key role of the polymerization kinetics characterized by the Trommsdorff-Norrish effect. Moreover, as the AgNW pattern becomes clearer, the electrical resistance along the patterns decreases and more complex patterns can be produced, indicating the potential of the method. Overall, the present patterning method constitutes a simple approach that only requires illumination through a mask to generate the AgNW pattern, which renders it a promising alternative for patterning nanocrystals in polymer films.

Angewandte Chemie, May 26, 2020

Beitrag wurde nach Begutachtung und Überarbeitung sofort als "akzeptierter Artikel" (Accepted Art... more Beitrag wurde nach Begutachtung und Überarbeitung sofort als "akzeptierter Artikel" (Accepted Article; AA) publiziert und kann unter Angabe der unten stehenden Digitalobjekt-Identifizierungsnummer (DOI) zitiert werden. Die deutsche Übersetzung wird gemeinsam mit der endgültigen englischen Fassung erscheinen. Die endgültige englische Fassung (Version of Record) wird ehestmöglich nach dem Redigieren und einem Korrekturgang als Early-View-Beitrag erscheinen und kann sich naturgemäß von der AA-Fassung unterscheiden. Leser sollten daher die endgültige Fassung, sobald sie veröffentlicht ist, verwenden. Für die AA-Fassung trägt der Autor die alleinige Verantwortung.

Physics of Fluids, 2015

In general, the sedimentation velocities of microparticles in liquids are not uniform due to long... more In general, the sedimentation velocities of microparticles in liquids are not uniform due to long-ranged hydrodynamic interactions. Although the velocity fluctuations have been extensively studied experimentally, numerically, and theoretically, the effect of charges of microparticles on the velocity fluctuations is not yet reported. This is probably due to some difficulties in the detection of optical signals from the micron-sized particles dispersed in water where the refractive index is more or less different, leading to serious scattering and attenuation of visible light. So far, since the dynamic ultrasound scattering technique was a good candidate to observe micron- and nano-sized particles in optically opaque systems, we investigated the velocity fluctuations ΔV of microparticles in water. In this study, we show that the velocity fluctuations of charged silica particles exhibit anomalous rise in the concentration dependence of ΔV and show that such a behavior can be suppressed by adding a small amou...

Ultrasonics, Jul 1, 2013

Multi-echo reflection ultrasound spectroscopy (MERUS), which enables one to simultaneously evalua... more Multi-echo reflection ultrasound spectroscopy (MERUS), which enables one to simultaneously evaluate the attenuation coefficient a, the sound velocity v and the density q, has been developed for measurements of elastic moduli. In the present study, the technique was further developed to analyze systems undergoing gelation where an unphysical decrease in the apparent density was previously observed after polymerization. The main reason for this problem was that the shrinkage accompanying the gelation led to a small gap between the cell wall and the sample, resulting in the superposition of the reflected signals which were not separable into individual components. By taking into account the multiply reflecting echoes at the interface of the gap, the corrected densities were systematically obtained and compared with the results for the floating test. The present technique opens a new route to simultaneously evaluate the three parameters a, v and q and also the sample thickness for solid thin films.

IEICE Technical Report; IEICE Tech. Rep., Jul 22, 2019

IEICE Technical Report; IEICE Tech. Rep., Jul 20, 2017

Ultrasonics, Mar 1, 2019

The attenuation coefficient and the phase velocity of micrometer-sized polydivinylbenzene particl... more The attenuation coefficient and the phase velocity of micrometer-sized polydivinylbenzene particles in water were investigated by ultrasound spectroscopy equipped with 10-30 MHz longitudinal wave transducers. While the surrounding liquid could be assumed to be inviscid for large particles with the size comparable to the wavelength of longitudinal ultrasound, the viscous and thermal waves were considered to have important roles with decreasing the particle size because the particle size becomes comparable with those wavelengths. In this study, these contributions were systematically investigated by changing the particle-size.

Polymer Preprints, Japan, 2005

IEICE Technical Report; IEICE Tech. Rep., Jul 24, 2015

Chaos, Jun 1, 2015

Phase separation of mixtures composed of a guest polymer dissolved in monomer of a host polymer w... more Phase separation of mixtures composed of a guest polymer dissolved in monomer of a host polymer was induced by photopolymerization. From the polymerization kinetics, it was found that for the host polymer with the glass transition temperature (T g) higher than the experimental temperature, the Trommsdorff-Norrish effect emerges, providing a method to terminate the phase separation at various intermediate stages of the process and thereby a variety of morphologies can be constructed. For the host polymers with (T g) lower than the experimental temperature, the freezing process of morphology is not complete, leading to the secondary phase separation inside the domains already generated by the primary process. The kinetics of this secondary phase separation indicates that the peculiar morphology like "sunny-side-up egg"-like structures was generated via spinodal decomposition. The experimental results obtained in this study show that the competition between photopolymerization and phase separation can provide a useful method of materials design in the micro-and sub-micrometer scales. V

Macromolecular Symposia, Oct 1, 2000

Acs Symposium Series, 2003

In 1991, we editors met at a Gordon Research Conference on Oscillations and Dynamic Instabilities... more In 1991, we editors met at a Gordon Research Conference on Oscillations and Dynamic Instabilities in Chemical Systems. Of the more than 120 participants, we were the only two who were working on poly meric systems. It was our dream that some day we would hold a sym posium dedicated to nonlinear dynamics and polymers. This book is a realization of that dream. This book is based on presentations made during the symposium Nonlinear Dynamics in Polymeric Systems held at the 224th National Meeting of the American Chemical Society (ACS) in Boston, Massa chusetts on August 18-22, 2002, which was cosponsored by the ACS Divisions of Polymer Chemistry, Inc. and Physical Chemistry. More than 30 participants presented their work. This volume brings together two fields of science that have, until recently, interacted only rarely. The central role of polymer science in understanding the substances of modern life and, indeed, of life itself is obvious. Nonlinear dynamics is a newer science, but one that has afford ed important insights into phenomena in chemistry, physics, mathematics, biology, geology, and even the social sciences. Perhaps because so much of polymer science occurs in an industrial context, where nonlinear behavior such as chaos is typically seen as something to be avoided, even at the cost of suboptimal operating conditions, the amount of crossfertilization between these areas has been limited. The purpose of this volume is to bring together practitioners in both fields to discuss the progress that has been made in unveiling and exploiting the nonlinear xi

超音波エレクトロニクスの基礎と応用に関するシンポジウム(CD-ROM), 2016

IEICE Technical Report; IEICE Tech. Rep., Oct 15, 2009

超音波エレクトロニクスの基礎と応用に関するシンポジウム講演予稿集, 2012

IEICE technical report. Ultrasonics, Jul 4, 2014

超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集, Nov 5, 2015

ECS transactions, Sep 23, 2016

Performance of supercapacitors is often influenced by their internal resistance since it causes u... more Performance of supercapacitors is often influenced by their internal resistance since it causes unfavorable effects such as energy dissipation and delay of charge transport during charging/discharging. In the present study, we prepared monolithic metal nanowire array electrodes in aiming at suppressing the internal resistance of supercapacitors, and examined the influence of the defect structures present in the nanowire array electrodes. Performance of the supercapacitors was investigated by using galvanostatic charge/discharge measurement, cyclic voltammetry, and electrochemical impedance spectroscopy.

ACS Applied Materials & Interfaces, Dec 9, 2021

Patterning nanocrystals in polymer films is essential for the widespread use of nanocrystals in v... more Patterning nanocrystals in polymer films is essential for the widespread use of nanocrystals in various fields from optics to electronics; therefore, the development of patterning methods for nanocrystals is an important task. Here, we report a unique approach for patterning silver nanowires (AgNWs) using a thermodynamic driving force induced by transient concentration gradients in reaction mixtures. The procedure starts with the preparation of a photocurable monomer solution containing homogeneously dispersed AgNWs. Ultraviolet illumination through a straight-line mask reduces the polymerization rate of monomers in the masked area, decreasing the polymer concentration in comparison with that in the unmasked area. Such transient polymer concentration gradients yield imbalances in the chemical potentials of AgNWs, inducing the migration of AgNWs to form a straight-line pattern of AgNWs. The pattern of AgNWs was visualized via photoluminescence imaging under a laser scanning confocal microscope and compared with the light patterns applied to the mixture. These observations revealed that the magnitude of the AgNW migration is enhanced as the transient concentration gradient increases by thickening the mask to decrease the intensity of light passing through the mask. The structural features of the AgNW pattern were reproduced using numerical simulations based on a set of reaction-diffusion equations, which suggested the key role of the polymerization kinetics characterized by the Trommsdorff-Norrish effect. Moreover, as the AgNW pattern becomes clearer, the electrical resistance along the patterns decreases and more complex patterns can be produced, indicating the potential of the method. Overall, the present patterning method constitutes a simple approach that only requires illumination through a mask to generate the AgNW pattern, which renders it a promising alternative for patterning nanocrystals in polymer films.

Angewandte Chemie, May 26, 2020

Beitrag wurde nach Begutachtung und Überarbeitung sofort als "akzeptierter Artikel" (Accepted Art... more Beitrag wurde nach Begutachtung und Überarbeitung sofort als "akzeptierter Artikel" (Accepted Article; AA) publiziert und kann unter Angabe der unten stehenden Digitalobjekt-Identifizierungsnummer (DOI) zitiert werden. Die deutsche Übersetzung wird gemeinsam mit der endgültigen englischen Fassung erscheinen. Die endgültige englische Fassung (Version of Record) wird ehestmöglich nach dem Redigieren und einem Korrekturgang als Early-View-Beitrag erscheinen und kann sich naturgemäß von der AA-Fassung unterscheiden. Leser sollten daher die endgültige Fassung, sobald sie veröffentlicht ist, verwenden. Für die AA-Fassung trägt der Autor die alleinige Verantwortung.

Physics of Fluids, 2015

In general, the sedimentation velocities of microparticles in liquids are not uniform due to long... more In general, the sedimentation velocities of microparticles in liquids are not uniform due to long-ranged hydrodynamic interactions. Although the velocity fluctuations have been extensively studied experimentally, numerically, and theoretically, the effect of charges of microparticles on the velocity fluctuations is not yet reported. This is probably due to some difficulties in the detection of optical signals from the micron-sized particles dispersed in water where the refractive index is more or less different, leading to serious scattering and attenuation of visible light. So far, since the dynamic ultrasound scattering technique was a good candidate to observe micron- and nano-sized particles in optically opaque systems, we investigated the velocity fluctuations ΔV of microparticles in water. In this study, we show that the velocity fluctuations of charged silica particles exhibit anomalous rise in the concentration dependence of ΔV and show that such a behavior can be suppressed by adding a small amou...

Ultrasonics, Jul 1, 2013

Multi-echo reflection ultrasound spectroscopy (MERUS), which enables one to simultaneously evalua... more Multi-echo reflection ultrasound spectroscopy (MERUS), which enables one to simultaneously evaluate the attenuation coefficient a, the sound velocity v and the density q, has been developed for measurements of elastic moduli. In the present study, the technique was further developed to analyze systems undergoing gelation where an unphysical decrease in the apparent density was previously observed after polymerization. The main reason for this problem was that the shrinkage accompanying the gelation led to a small gap between the cell wall and the sample, resulting in the superposition of the reflected signals which were not separable into individual components. By taking into account the multiply reflecting echoes at the interface of the gap, the corrected densities were systematically obtained and compared with the results for the floating test. The present technique opens a new route to simultaneously evaluate the three parameters a, v and q and also the sample thickness for solid thin films.

IEICE Technical Report; IEICE Tech. Rep., Jul 22, 2019

IEICE Technical Report; IEICE Tech. Rep., Jul 20, 2017

Ultrasonics, Mar 1, 2019

The attenuation coefficient and the phase velocity of micrometer-sized polydivinylbenzene particl... more The attenuation coefficient and the phase velocity of micrometer-sized polydivinylbenzene particles in water were investigated by ultrasound spectroscopy equipped with 10-30 MHz longitudinal wave transducers. While the surrounding liquid could be assumed to be inviscid for large particles with the size comparable to the wavelength of longitudinal ultrasound, the viscous and thermal waves were considered to have important roles with decreasing the particle size because the particle size becomes comparable with those wavelengths. In this study, these contributions were systematically investigated by changing the particle-size.

Polymer Preprints, Japan, 2005

IEICE Technical Report; IEICE Tech. Rep., Jul 24, 2015

Chaos, Jun 1, 2015

Phase separation of mixtures composed of a guest polymer dissolved in monomer of a host polymer w... more Phase separation of mixtures composed of a guest polymer dissolved in monomer of a host polymer was induced by photopolymerization. From the polymerization kinetics, it was found that for the host polymer with the glass transition temperature (T g) higher than the experimental temperature, the Trommsdorff-Norrish effect emerges, providing a method to terminate the phase separation at various intermediate stages of the process and thereby a variety of morphologies can be constructed. For the host polymers with (T g) lower than the experimental temperature, the freezing process of morphology is not complete, leading to the secondary phase separation inside the domains already generated by the primary process. The kinetics of this secondary phase separation indicates that the peculiar morphology like "sunny-side-up egg"-like structures was generated via spinodal decomposition. The experimental results obtained in this study show that the competition between photopolymerization and phase separation can provide a useful method of materials design in the micro-and sub-micrometer scales. V