Published Papers - NAKAHARA Yoshio

多波長励起光を備えた光熱変換顕微鏡による水中でのチオリンゴ酸修飾銀ナノ粒子の凝集挙動の定量評価

中原佳夫, 宮崎 淳, 廣野碧唯, 家永隆史, 矢嶋摂子 （Part： Lead author,　Corresponding author )

分析化学   74 ( 1-2 ) 23 - 28   2025.01  [Refereed]

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 （Part： Lead author,　Corresponding author )

ACS Omega   9   19932 - 19939   2024.04  [Refereed]

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   433 - 448   2024.04  [Refereed]

　View Summary

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.

DOI

Polysilsesquioxane Gate Dielectric Layers Cured by Ultra‐Violet Light Irradiation Using Thiol‐Ene Reaction for Organic Thin‐Film Transistors

Yoshio Nakahara, Ken-ichiro Yamane, Tomoaki Nakagami, Kazuyuki Uno, Ichiro Tanaka （Part： Lead author,　Corresponding author )

physica status solidi (a) ( Wiley )    2200895   2023.04  [Refereed]

DOI

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 （Part： Lead author,　Corresponding author )

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

DOI

Fluorescent sensing with nanoparticles

Yoshio Nakahara （Part： Lead author,　Last author,　Corresponding author )

Analytical Sciences   38 ( 11 ) 1369 - 1370   2022.11  [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   655   130228   2022.09  [Refereed]

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 （Part： Corresponding author )

RSC Advances   12   14535 - 14543   2022.05  [Refereed]

DOI

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 （Part： Lead author,　Corresponding author )

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

DOI

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

JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY ( TAYLOR & FRANCIS INC )  42 ( 8 ) 1218 - 1224   2021.06  [Refereed]

　View Summary

The influence of alkyl chain structures in sodium alkylsulfates (ASs) on their rheological properties was investigated in this study. Dilational viscoelasticity at the air-water interface, dynamic surface tension, and foam property were quantitatively evaluated in aqueous solutions of ASs with different hydrocarbon chains, and the relationship was systematically discussed. The experimental results show that the alkyl chain plays an important role in the interfacial dilational properties. For ASs with straight alkyl chains, AS with the longer alkyl chain showed the maximum value of the interfacial dilational viscoelasticity at the lower concentration. The longer the alkyl chain of AS was the larger the maximum value of the interfacial dilational viscoelasticity was. The frequency dependence of the interfacial dilational viscoelasticity was confirmed only in the range of high surfactant concentrations, suggesting that the interfacial relaxation process is mainly controlled by the diffusion of the surfactants. As for the relationship between interfacial dilational viscoelasticity and foam property, it was found that the maximum value of the interfacial dilational viscoelasticity was correlated with the foam stability under the conditions.

DOI

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 （Part： Corresponding author )

Bulletin of the Chemical Society of Japan   94 ( 5 ) 1616 - 1624   2021.06  [Refereed]

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]

　View Summary

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).

DOI

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

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN ( The Chemical Society of Japan )  94 ( 2 ) 542 - 548   2021.02  [Refereed]

DOI

Investigation of Photo-Initiators for Ultra-Violet Light Cured Polysilsesquioxane Gate Dielectric Layers of Organic Thin Film Transistors

秦野航輔, 中原佳夫, 宇野和行, 田中一郎

材料   69 ( 10 ) 712 - 716   2020.10  [Refereed]

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

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

DOI

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

Nakahara Yoshio, Kunitsu Yuki, Ozaki Nobuhiko, Tanaka Mutsuo, Yajima Setsuko （Part： Lead author,　Corresponding author )

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

DOI

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]

　View Summary

© 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.

DOI

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 （Part： Corresponding author )

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

DOI

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 （Part： Corresponding author )

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

DOI

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 （Part： Lead author,　Corresponding author )

Supramolecular Chemistry ( Taylor and Francis Ltd. )  30 ( 8 ) 697 - 705   2018.08  [Refereed]

　View Summary

In this study, we report the highly sensitive extraction-fluorometric detection system of Na+ using flow injection analysis with a tetraester derivative of fluorescent calix[4]arene. In liquid-liquid extraction experiments, the fluorescent intensity of calix[4]arene derivative 1 bearing a p-nitrophenol moiety was highly dependent on pH and the Na+ concentration in the aqueous phase. On the other hand, such phenomenon was not observed in the case of calix[4]arene derivative 2, which is almost the same structure as 1 except for a p-nitrophenol moiety. These results show that the proton dissociation of the p-nitrophenol moiety decisively affects the fluorescence intensity of 1. Owing to these fluorescence responsiveness, a calibration graph of the Na+ concentration could be successfully prepared using flow injection analysis with good linearity at the tens of nanomolar level. The tetraester scaffold of calix[4]arene was essential to the detection of Na+ in such a very low concentration range.

DOI