Published Papers - YAJIMA Setsuko

Quantitative Evaluation of Aggregation Behaviors of Thiomalic-acid-modified Silver Nanoparticles in Water by Photothermal Microscopy with Multiwavelength Excitation

Yoshio NAKAHARA, Jun MIYAZAKI, Aoi HIRONO, Takashi IENAGA, Setsuko YAJIMA

BUNSEKI KAGAKU ( Japan Society for Analytical Chemistry )  74 ( 1.2 ) 23 - 28   2025.01  [Refereed]

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Polydopamine-Coated Solid Silica Nanoparticles Encapsulating IR-783 Dyes: Synthesis and NIR Fluorescent Cell Imaging

Yoshio Nakahara, Haruki Nakabayashi, Jun Miyazaki, Mitsuru Watanabe, Toshiyuki Tamai, Setsuko Yajima

ACS Omega ( American Chemical Society (ACS) )  9 ( 18 ) 19932 - 19939   2024.04  [Refereed]

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Properties of surface layers of polyethylene naphthalate substrates modified by ultraviolet light irradiation for their electroless deposition

Toshiyuki Tamai, Mitsuru Watanabe, Rie Kakehashi, Yoshio Nakahara, Setsuko Yajima

Colloid and Polymer Science   302 ( 3 ) 433 - 448   2024.03  [Refereed]

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The properties of thin surface layers of polymer substrates should be investigated and controlled for their application in electroless deposition. In this paper, polyethylene naphthalate (PEN) and polyethylene terephthalate (PET) substrates were modified by plasma treatment, ultraviolet (UV)/ozone treatment, or UV (254 nm) irradiation. The chemical and physical properties of the modified layer were studied by measuring contact angle and zeta potential, field-emission scanning electron microscope (FE-SEM) imaging, and infrared spectroscopy. The condition of the surface modification affected oxygenation of the polymer chains. The oxygenation formed hydrophilic surface functional groups and relatively polar low-molecular-weight fragments resulting from the scission of the polymer chains. The surface functional groups and the fragments governed the properties of the modified layer. Adhesive metal films were electrolessly deposited on the thinner modified layer having the hydrophilic functional groups. In contrast, the thicker modified layer containing the fragments decreased the adhesion of the metal films. For example, UV/ozone treatment of the PEN substrate formed the thicker modified layer, on which no adhesive metal films were deposited. These findings illustrate that optimizing the condition of the surface modification thoroughly is feasible to form the modified layer having the chemical and physical properties appropriate for depositing adhesive metal films.

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Quantitative Discrimination of Silver and Gold Nanoparticles Immobilized in Transparent Plastic Film by Photothermal Microscopy with Multiwavelength Excitation

Yoshio Nakahara, Jun Miyazaki, Aoi Hirono, Takashi Ienaga, Setsuko Yajima

Chemistry Letters   52 ( 2 ) 113 - 115   2023.02  [Refereed]

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イオンセンサーの応答機構の解明を目指したオルガノゲルのイオン選択的構造変化の観測

矢嶋 摂子, 増永 啓康, 佐々木 園 （Part： Lead author,　Corresponding author )

SPring-8/SACLA利用研究成果集   10 ( 6 ) 485 - 487   2022.12  [Refereed]

Influencing foam properties of aqueous bis(2-ethylhexyl)sulfosuccinate solutions by addition of polypropylene-glycol-modified and amino-modified silica nanoparticles

Keita Aono, Hiroya Shiba, Furitsu Suzuki, Yoshihiro Yomogida, Motomitsu Hasumi, Shinpei Kado, Yoshio Nakahara, Setsuko Yajima

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS ( ELSEVIER )  655   2022.12  [Refereed]

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The effect of silica nanoparticle (SiO2NP) addition on the air-water interfacial rheology and foam properties was investigated in aqueous solutions of bis(2-ethylhexyl)sulfosuccinate (AOT), an anionic surfactant. Two types of SiO2NPs were prepared: polypropylene-glycol-modified SiO2NPs (PPG-SiO2NPs) and amino-modified SiO2NPs (NH2-SiO2NPs). The addition of SiO2NPs stabilized the foam in the aqueous AOT solution in all cases, but the effect on the air-water interfacial behavior differed depending on the SiO2NP type. Adsorption of NH2-SiO2NPs to the air-water interface improved the air-water interfacial dilational viscoelasticity (E), enhancing foam stability. Although PPG-SiO2NPs did not adsorb to the air-water interface, the movement of AOT molecules to the air -water interface was partially suppressed by hydrophobic interaction with PPG-SiO2NPs in the bulk aqueous solution. This event limited the decrease in E, thereby stabilizing the foam.

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Room-temperature coalescence of Pd nanoparticles with sacrificial templates and sintering agents, and their catalytic activities in the Suzuki coupling reaction.

Soichiro Okada, Yoshio Nakahara, Mitsuru Watanabe, Toshiyuki Tamai, Yasuyuki Kobayashi, Setsuko Yajima

RSC Advances   12   14535 - 14543   2022.05  [Refereed]

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Synthesis of Silica Nanoparticles with Physical Encapsulation of Near-Infrared Fluorescent Dyes and Their Tannic Acid Coating

Yoshio Nakahara, Yukiho Nakajima, Soichiro Okada, Jun Miyazaki, Setsuko Yajima

ACS Omega ( American Chemical Society (ACS) )  6 ( 27 ) 17651 - 17659   2021.07  [Refereed]

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Room-Temperature Coalescence of Tri-n-Octylphosphine-Oxide-Capped Cu-Ag Core-Shell Nanoparticles: Effect of Sintering Agent and/or Reducing Agent

Soichiro Okada, Yoshio Nakahara, Mitsuru Watanabe, Toshiyuki Tamai, Yasuyuki Kobayashi, Setsuko Yajima

Bulletin of the Chemical Society of Japan   64 ( 5 ) 1616 - 1624   2021.05  [Refereed]

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Metal nanoparticle pastes are useful for nanoinks to form fine conductive patterns in printed electronics. This study reports a novel method for room-temperature coalescence of Cu-Ag core-shell nanoparticles (Cu@Ag NPs), which are expected to have the properties of both migration and oxidation resistance originating from Cu and Ag, respectively. First, oleylamine/oleic-acid capped Cu@Ag NPs were synthesized by the galvanic replacement method. Second, the ligand exchange reaction to tri-n-octylphosphine oxide (TOPO) was carried out on the surface of Cu@Ag NPs. Finally, TOPOcapped Cu@Ag NPs were dipped into methanol containing a sintering agent and/or a reducing agent. When HCl was added as a sintering agent to methanol, the crystallite size of Cu@Ag NPs significantly increased. Furthermore, the almost complete removal of organic compounds and suppression of significant oxidation of Ag and Cu were observed. In consideration of these results, a Cu/Ag conductive thin film was prepared from TOPO-capped Cu Ag NPs by dipping into methanol containing HCl at room temperature under air atmosphere. Electrical resistivity of the obtained Cu/Ag thin film was (5.1 « 1.7).

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Foam Destabilization Effect of Sodium Bis(2-ethylhexyl)sulfosuccinate on Sodium Alkylsulfate Aqueous Solutions Based on Its Fast Surface Tension Gradient Relaxation

Keita Aono, Furitsu Suzuki, Yoshihiro Yomogida, Motomitsu Hasumi, Shinpei Kado, Yoshio Nakahara, Setsuko Yajima （Part： Corresponding author )

Bulletin of the Chemical Society of Japan ( The Chemical Society of Japan )  94 ( 2 ) 542 - 548   2021.02  [Refereed]

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Effects of Polypropylene Glycol at Very Low Concentrations on Rheological Properties at the Air–Water Interface and Foam Stability of Sodium Bis(2-ethylhexyl)sulfosuccinate Aqueous Solutions

Keita Aono, Furitsu Suzuki, Yoshihiro Yomogida, Motomitsu Hasumi, Shinpei Kado, Yoshio Nakahara, Setsuko Yajima （Part： Corresponding author )

Langmuir ( American Chemical Society (ACS) )  36 ( 34 ) 10043 - 10050   2020.09  [Refereed]

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Relationship between air-water interfacial dilational viscoelasticity and foam property in aqueous solutions of sodium alkylsulfates with different hydrocarbon chains

Keita Aono, Furitsu Suzuki, Yoshihiro Yomogida, Tetsuya Okano, Shinpei Kado, Yoshio Nakahara, Setsuko Yajima （Part： Corresponding author )

Journal of Dispersion Science and Technology ( Informa UK Limited )    1 - 7   2020.02  [Refereed]

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Preparation of Ag2Se QDs with excellent aqueous dispersion stability by orgainc coating with aqueous ATRP

Yoshio Nakahara, Yuki Kunitsu, Nobuhiko Ozaki, Mutsuo Tanaka, Setsuko Yajima

POLYMER BULLETIN ( Springer Science and Business Media LLC )  76 ( 9 ) 4753 - 4768   2019.09  [Refereed]

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Surface modification of polyethylene naphthalate substrates by ultraviolet light-irradiation and assembling multilayers and their application in electroless deposition: The chemical and physical properties of the stratified structure

T. Tamai, M. Watanabe, Y. Kobayashi, J. Kobata, Y. Nakahara, S. Yajima

Colloids and Surfaces A: Physicochemical and Engineering Aspects   575   230 - 236   2019.08  [Refereed]

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© 2019 Elsevier B.V. Electroless metal deposition on polymer surface is useful for fabricating metallic patterns. The surfaces of polyethylene naphthalate (PEN) substrates were modified by ultraviolet (UV) light -irradiation and layer-by-layer assembly of polyelectrolyte multilayer thin films, and then nickel and copper films were electrolessly deposited on the substrate surfaces to form the stratified structure, PEN-substrate/multilayer/metal-film. The chemical and physical properties of the modified layer in the substrate surfaces were studied by X-ray photoelectron spectroscopy, nanoindentation test, and measuring contact angle. The properties of the UV-irradiated surface layer depended on the condition of surface modification and affected the adhesion of the deposited metal film. Adhesive nickel films were deposited on the UV (254 nm)-irradiated PEN substrates that have thin modified layers compatible with the multilayers. In contrast, no adhesive nickel films were deposited on the substrate surfaces having thicker and fragile modified layers. These contrasting results are originated from the oxygenation and crosslinking of the polymer chains in the substrate surface layers, and reactive species formed by the UV irradiation induce the oxygenation and crosslinking. The properties of the modified substrate-surface play an important role for depositing adhesive metal films.

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Crystallite Size Increase of Silver Nanoparticles by Ligand Exchange and Subsequent Washing Process with Antisolvent

Okada Soichiro, Nakahara Yoshio, Watanabe Mitsuru, Tamai Toshiyuki, Yajima Setsuko

JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY   19 ( 8 ) 4565 - 4570   2019.08  [Refereed]

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Room-Temperature Sintering of Tri-n-Octylphosphine-Oxide-Capped Silver Nanoparticle Paste by Dipping into an Organic Solvent Containing a Sintering Agent

Okada Soichiro, Nakahara Yoshio, Watanabe Mitsuru, Tamai Toshiyuki, Kobayashi Yasuyuki, Yajima Setsuko

JOURNAL OF PHYSICAL CHEMISTRY C ( American Chemical Society (ACS) )  123 ( 23 ) 14118 - 14125   2019.06  [Refereed]

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A tetraester derivative of fluorescent calix[4]arene bearing a proton-ionizable moiety for highly sensitive extraction-fluorometric determination of sodium ion

Yoshio Nakahara, Yuta Furuno, Hitoshi Iwamoto, Setsuko Yajima, Keiichi Kimura

Supramolecular Chemistry ( Informa UK Limited )  30 ( 8 ) 697 - 705   2018.08  [Refereed]

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Near-Infrared Dye Immobilized in Porous Silica Layer on Gold Nanorod and Its Fluorescence Enhancement by Strengthened Electromagnetic Field Based on Surface Plasmon Resonance

Yoshio Nakahara, Ryoko Takeda, Toshiyuki Tamai, Setsuko Yajima, Keiichi Kimura

Plasmonics ( Springer New York LLC )  13 ( 2 ) 645 - 652   2018.04  [Refereed]

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We report immobilizing Nile Blue A, which is a cationic fluorescent dye emitting in the near-infrared region, in the porous silica layer on gold nanorod and its fluorescence enhancement by strengthened electromagnetic field based on surface plasmon resonance. The effect of the spacer corresponding to the silica layer on the metal-enhanced fluorescence effect is also discussed in detail. Hollow silica nanorod was in advance prepared, and then the silica layer was partly etched to increase the porosity for the improvement of the mass transfer. Subsequently, gold nanorod was fabricated in the restricted space of hollow silica nanorod. Finally, Nile Blue A was physically immobilized in the porous silica layer on gold nanorod through electrostatic interactions. The fluorescence enhancement of Nile Blue A based on surface plasmon resonance was semi-quantified by comparative experiments using hollow silica nanorod, which is exactly the same structure except for gold as silica-coated gold nanorod. Since our results demonstrated that the porosity degree of the silica layer significantly affected the fluorescence enhancement of Nile Blue A, it is hopeful that our design concept, distinct from the conventional one, can lay a foundation for further development of near-infrared fluorescence nanomaterials.

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Effect of Protective Agents on Silver Nanoparticle Preparation by Vacuum Evaporation on Running Hydrocarbon Solution

Ienaga Takashi, Nakahara Yoshio, Yajima Setsuko, Kimura Keiichi

JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY   18 ( 4 ) 2547 - 2554   2018.04  [Refereed]

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Comparison of Physical Adsorption Strength of Protective Agents via Ligand Exchange of Silver Nanoparticles Prepared by Vacuum Evaporation on Running Oil Substrate (vol 90, pg 1251, 2017)

Ienaga Takashi, Okada Soichiro, Nakahara Yoshio, Watanabe Mitsuru, Tamai Toshiyuki, Yajima Setsuko, Kimura Keiichi

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   91 ( 3 ) 506   2018.03  [Refereed]

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