Faculty Profiles - YAMAMOTO Tetsuya

Size Control of Polymeric Particle in Soap-Free Emulsion Polymerization Invited Reviewed

Tetsuya Yamamoto, Ko Higashitani

KONA Powder and Particle Journal Vol. 35 ( 0 ) page： 66 - 79 2018

Growth mechanism of soap-free polymerization of styrene investigated by AFM Reviewed

Yamamoto, T Nakayama, M Kanda, Y Higashitani, K

Journal of Colloid and Interface Science Vol. 297 ( 1 ) page： 112-121 2006.5

Nanoparticle formation of β-carotene by mixing supercritical carbon dioxide antisolvent with liquefied dimethyl ether feed solution using swirl mixer Reviewed International coauthorship

Li Mei, Hideki Kanda, Li Zhu, Tao Wang, Tetsuya Yamamoto

Advanced Powder Technology Vol. 36 ( 6 ) page： 104871 - 104871 2025.6

Formation of Hollow Nanoparticles by Inclusion and Decomposition of Azo Compounds and Their Properties International coauthorship

Tetsuya YAMAMOTO

Hosokawa Powder Technology Foundation ANNUAL REPORT 2025.5

Fiber-Optic Sensor Modified by Electrospun Polymer/Ti3C2 MXene–TiO2 for Dimethyl Sulfoxide Sensing Reviewed International coauthorship

Tao Wang, Li Zhu, Yunpeng Yue, Yasuhito Mukai, Hideki Kanda, Tetsuya Yamamoto

Talanta Vol. 287 page： 127630 - 127630 2025.5

Introduction of oxygen‐containing functional groups to carbon fiber surfaces to enhance the bending strength of <scp>PA6</scp>‐based carbon‐fiber‐reinforced thermoplastics International coauthorship

Sulchan Kim, Akiko Yagi, Tetsuya Yamamoto

Polymer Composites 2025.4

Authorship：Last author,　Corresponding author Publishing type：Research paper (scientific journal) Publisher：Wiley

Abstract

Carbon‐fiber‐reinforced thermoplastics (CFRTPs) are recyclable composite materials with excellent mechanical properties. However, for CFRTPs to be used in automobile applications, enhanced mechanical properties are required. To meet this challenge, the surface adhesion between the carbon fibers and thermoplastics must be improved. In this study, we developed surface treatment techniques for carbon fibers using the radical initiator dimethyl 2,2′‐azobis(2‐methylpropionate) (V‐601) to introduce oxygen‐containing functional groups to the carbon fibers through radical chemical reactions. Using x‐ray photoelectron spectroscopy, we showed that the surface adhesion between the carbon fibers and a nylon thermoplastic resin (PA6) improved owing to hydrogen bonding with carbonyl groups on the carbon fiber surface, which enhanced the mechanical properties of the CFRTP. Moreover, we demonstrated control of the mechanical properties of the CFRTP by varying the V‐601‐acetone concentration. The findings of this study can be used to develop automobile applications for PA6‐based CFRTPs.

Highlights

Carbon‐fiber‐reinforced thermoplastics (CFRTPs) have good mechanical properties.

Surface adhesion between carbon fibers and thermoplastic resin PA6 was improved.

Surface treatment techniques for carbon fibers were developed.

Dimethyl 2,2′‐azobis(2‐methylpropionate) (V‐601) was used for this.

DOI： 10.1002/pc.29919

Brilliant and Angular‐Independent Photonic Balls Using High‐Refractive‐Index Inorganic‐Polymer Hybrid Materials Reviewed International coauthorship Open Access

Yangnan Jiang, Ayano Shirai, Michinari Kohri, Ryosuke Ohnuki, Shinya Yoshioka, Tetsuya Yamamoto, Yukikazu Takeoka

Advanced Optical Materials Vol. 13 ( 9 ) 2025.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley

Abstract

In the modern era, structural color materials are regarded as safe and promising alternatives to colorants that contain harmful components. However, developing structural color materials that exhibit vivid colors with minimal angular dependence is crucial for their practical application. In this study, spherical colloidal crystals (photonic balls) with bright colors and effectively suppressed angular dependence are developed using monodisperse high refractive index CeO₂ particles. To fabricate these photonic balls, CeO₂@PDA particles are synthesized by coating CeO₂ particles with polydopamine (PDA), a black component. The light‐absorbing PDA coating on each particle uniformly reduces the multiple scattering of light to form a black background, allowing the CeO₂@PDA photonic balls to exhibit brilliant structural colors. Compared to SiO₂ particles photonic balls, which are widely studied in previous research, CeO₂@PDA photonic balls have a significantly reduced angular dependence of structural color hue due to their composition of materials with a higher refractive index. Additionally, the CeO₂@PDA photonic balls are heat‐treated in a nitrogen atmosphere, transforming the polymer component on the particle surface into a black carbonaceous material with a higher refractive index. This process further reduces the angular dependence of structure color hues observed from the photonic balls and improves color vibrancy.

DOI： 10.1002/adom.202402863

Open Access

Effect of electrostatic interaction between particle and substrate on the colloidal layer structure prepared by convective self-assembly Reviewed International coauthorship

Akane Oka, Tetsuya Yamamoto, Hidetaka Kawakita, Keisuke Ohto, Shintaro Morisada

Advanced Powder Technology Vol. 36 ( 3 ) page： 104811 - 104811 2025.3

Synthesis of Polymer Nano Particle using Packed Reactor with Glass Beads Invited Reviewed International coauthorship

Tetsuya Yamamoto, Natsuhide Hori, Ayumi Morino, Subaru Okuda, Hideki Kanda

Journal of the Society of Powder Technology, Japan Vol. 62 ( 2 ) page： 91 - 94 2025.2

Environmentally Friendly Synthesis of Polymer Nanoparticles in a Packed Reactor Using Glass Beads Invited Reviewed International coauthorship

Tetsuya Yamamoto, Ayumi Morino, Hideki Kanda, Ayumu Seki, Toru Ishigami

Macromolecular Reaction Engineering Vol. 19 ( 1 ) 2025.2

Removal of acetyl-rich impurities from chitosan using liquefied dimethyl ether Reviewed International coauthorship

Tao Wang, Kaito Kusumi, Li Zhu, Li Mei, Aiya Manabe, Mohammad Reza Asghari, Bahram Hosseinzadeh Samani, Tetsuya Yamamoto, Hideki Kanda

International Journal of Biological Macromolecules Vol. 280 page： 136381 - 136381 2024.11

N,N-dimethylformamide detection and refractive index sensing using an electrospun polymer/Ti3C2 MXene-TiO2 modified optical fiber sensor Reviewed International coauthorship

Tao Wang, Li Zhu, Yunpeng Yue, Mohammad Reza Asghari, Bahram Hosseinzadeh Samani, Tetsuya Yamamoto, Yasuhito Mukai, Hideki Kanda

Sensors and Actuators B: Chemical Vol. 417 page： 136143 - 136143 2024.10

Density and porosity analyses of porous hybrid microparticles containing gas in closed pores using centrifugal liquid sedimentation–dynamic light scattering combined analytical method Reviewed International coauthorship

Tetsuji Yamaguchi, Tetsuya Yamamoto

Analytical Sciences Vol. 40 ( 10 ) page： 1881 - 1888 2024.10

Improvement of carbon fiber oxidation resistance by thin ceramic coating using silica particles Reviewed International coauthorship

Kohei Kira, Tetsuya Yamamoto, Yoshiki Sugimoto, Izuru Shimabukuro, Aika Hikosaka, Toshihira Irisawa

Carbon Vol. 228 page： 119417 - 119417 2024.9

Carbon fiber‐reinforced thermoplastic synthesized by the hypercrosslinking reaction of polyether ether ketone Reviewed International coauthorship

Tetsuya Yamamoto, Takumi Nakamoto, Toshihira Irisawa

Polymer Composites Vol. 45 ( 12 ) page： 11473 - 11479 2024.8

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley

Abstract

Recently, thermoplastic resins were used as matrix to synthesize carbon fiber‐reinforced thermoplastic (CFRTP) for recycling it easily. In this study, a CFRTP with excellent mechanical properties and heat resistance was synthesized using a polyether ether ketone (PEEK) as a matrix resin. The PEEK resin was modified to form cross‐linked structures through Friedel–Crafts reaction alkylation. The synthesis temperature of CFRTP was optimized considering the mechanical properties of PEEK, and its heat resistance was enhanced because of the cross‐linked structures. Further, the cross‐linked PEEK resin was partially used as a matrix resin, and the mechanical properties of the CFRTP were enhanced. We plan to develop a method for recycling CFRTP using PEEK and crosslinked PEEK for synthesizing C/C composites by focusing on the high heat resistance of the crosslinked PEEK containing a large amount of carbon and reducing mass loss after heat treatment.

Highlights

CC bonds were introduced into the polyether ether ketone (PEEK) resin by Friedel–Crafts reaction alkylation.

Thermal properties of PEEK were enhanced by hypercrosslinking reaction.

Optimization of synthesized temperature was investigated to fabricate carbon fiber‐reinforced thermoplastic (CFRTP).

Mechanical properties were enhanced CFRTP modified with hypercrosslinking reaction.

DOI： 10.1002/pc.28579

Synthesis of Polystyrene Nanoparticles using Thermally Reversible Hydrogel as Polymerization Field Reviewed

Environmental-friendly extraction of di(2-ethylhexyl) phthalate from poly(vinyl chloride) using liquefied dimethyl ether Reviewed International coauthorship

Tao Wang, Hideki Kanda, Kaito Kusumi, Li Mei, Lijuan Zhang, Hiroshi Machida, Koyo Norinaga, Tetsuya Yamamoto, Hiroshi Sekikawa, Kengo Yasui, Li Zhu

Waste Management Vol. 183 page： 21 - 31 2024.6

Preparation of β-carotene nanoparticles using supercritical CO2 anti-solvent precipitation by injection of liquefied gas feed solution Reviewed International coauthorship

Hideki Kanda, Li Mei, Tetsuya Yamamoto, Tao Wang, Li Zhu

Journal of CO2 Utilization Vol. 83 page： 102831 - 102831 2024.5

High-Efficiency Polymerization for Synthesizing Polymer Nanoparticles in Melamine Foam Using Ultraviolet Irradiation Reviewed International coauthorship

Tetsuya Yamamoto, Haruyuki Morikawa

ACS Omega Vol. 9 ( 5 ) page： 5273 - 5277 2024.1

Hollow Particles Synthesized by Water-soluble and Oil-Soluble Initiators and the Mechanism of Incorporating an Oil-Soluble Initiator Reviewed

Tetsuya Yamamoto, Shinya Maeda, Mitsuo Hara

Results in Materials Vol. 19 page： 1004221 2023.9

Synthesis of core-shell composite particles with void layers and their application as absorbents

Vol. 41 page： 234 - 241 2023.7

Synthesis of polymer nanoparticles using methylcellulose gel as reactor Invited Reviewed

T. Yamamoto

Journal of Biological Macromolecules Vol. 23 ( 2 ) page： 37 - 45 2023.7

In-situ observations of growth process of polymer particles and antimicrobial activity Invited

Vol. 60 ( 6 ) page： 341 - 347 2023.6

Mechanisms of Formation and Growth of Polymer Particles by In-Situ Observations Invited

T. Yamamoto

Vol. 60 ( 4 ) page： 221 - 227 2023.4

カーボンナノチューブを表面修飾に利用した炭素繊維強化プラスチック Invited

山本徹也

化学工学誌 Vol. 87 ( 1 ) page： 47 - 47 2023.1

Enhancement of Surface Adhesion between Carbon Fiber and Thermoplastic Using Polymer Colloid Dispersed in n-Butanol Reviewed

Yamamoto, T.*, and S. Yabushita,

Results in Materials Vol. 16 page： 100322 - 100322 2022.12

Green Synthesis of Hollow Structures Through the Decomposition of Azo Compounds Incorporated Inside Polystyrene Particles Reviewed

T. Yamamoto, K. Tsutsumi, S. Maeda

ACS Omega Vol. 7 ( 32 ) page： 28556 - 28560 2022.8

Nanosizing of Polymeric Particles by Suppressing Growth via Heterocoagulation using a 3D Micro-Network Reactor Reviewed

S. Ouchi, H. Morikawa, M. Hara, and T. Yamamoto

Powder Technology Vol. 405 page： 117530 2022.6

Structural Design to Enhance Mechanical Properties of Carbon-Fiber-Reinforced Thermoplastics using Colloidal Particles and Soft and Hard Resins Reviewed

K. Kira, SulChan Kim, T. Yamamoto, K. Kato, M. Nomura

Composites Part C Vol. 6 page： 100211 2021.12

Stress graphitization behavior of c/c composites fabricated from milled short pitch-based carbon fibers and their electrical properties Reviewed

T. Irisawa, K. Nishimura, T. Yamamoto, Y. Tanabe, and n. Iwashita

Journal of Fiber Science and Technology Vol. 77 ( 11 ) page： 296 - 304 2021.11

Use of Hollow Colloids for Generating Nanovoids to Mitigate the Brittle Fracture of Carbon Fiber-Reinforced Thermoplastics Reviewed

Tetsuya Yamamoto, Yugo Terada

Composites Part A: Applied Science and Manufacturing Vol. 146 page： 106506 2021.10

三次元網目構造を反応場とした高分子ナノ粒子のサイズコントロール Invited Reviewed

大内慎也，山田尚輝，山本徹也

粉体工学会誌 Vol. 58 ( 9 ) page： 481 - 485 2021.9

Synthesis of activated carbon using bagasse and recycled carbon fibers Invited Reviewed

T. Yamamoto, Y. Makino, T. Irisawa

Chemical Engineering & Technology Vol. 44 ( 9 ) page： 1618 - 1622 2021.9

安全な破壊を実現する高強度CFRTPの開発

山本徹也

材料化学研究助成研究成果報告 Vol. 34 page： 49 - 53 2021.7

CFRPから回収した炭素繊維を利用した高機能性材料の開発

山本徹也

ホソカワ粉体工学振興財団年報 Vol. 28 page： 103 - 108 2021.5

Surfactant-free decellularization of porcine aortic tissue by subcritical dimethyl ether Reviewed International coauthorship

Kanda Hideki, Ando Daigo, Hoshino Rintaro, Yamamoto Tetsuya, Wahyudiono, Suzuki Shogo, Shinohara Satoshi, Goto, Motonobu

ACS Omega Vol. 6 ( 20 ) page： 13417 - 13425 2021.5

Naoki Yamada, Shinya Ouchi, Tetsuya Yamamoto

KAGAKU KOGAKU RONBUNSHU Vol. 47 ( 1 ) page： 11 - 16 2021.1

Dispersion of Nano-materials in Polymer Composite Materials Reviewed International coauthorship

Tetsuya Yamamoto, Yuya Takahashi, Naoya Toyoda

MATEC Web of Conferences Vol. 333 page： 11003 - 11003 2021.1

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：{EDP} Sciences

Polymer composites materials are the subject of extensive studies because of their novel properties compared with their constituent materials. Dispersion stability of sub-micron sized particles in the medium is important from the point of colloidal views. In the present study, dispersion of nano-materials in the matrix polymer is one of the most important problems to enhance their mechanical properties. We tackled this problem to carry out surface modification of the nano-materials, such as carbon nano tubes (CNTs), using amphiphilic polymers, poly<italic>N</italic>vinylacetamide (PNVA), synthesized thorough radical polymerization. Hydrogen bond worked between PNVA onto the modified nano-materials and hydrophilic matrix, such as polyvinyl alcohol (PVA), to enhance surface adhesions and dispersions of the nano-materials in the matrix. As a result, the mechanical properties of their composites materials were strengthened. When CNTs were used in PVA, the transparency of the composite was also increased due to improvement of their dispersions. In addition, if the CNTs formed the networks in the composites, the highly conductive and transparent polymer composite films were fabricated.

DOI： 10.1051/matecconf/202133311003

Creating a laminated carbon fiber-reinforced thermoplastic using polypropylene and nylon with a polypropylene colloid Reviewed

Tetsuya Yamamoto, Yusuke Ota

Composite Structures Vol. 255 page： 113038 - 113038 2021.1

Effects of carbon nanofibers on carbon fiber reinforced thermoplastics made with in situ polymerizable polyamide 6 Reviewed

Toshihira Irisawa, Masataka Shibata, Tetsuya Yamamoto, Yasuhiro Tanabe

Composites Part A: Applied Science and Manufacturing Vol. 138 page： 106051 - 106051 2020.11

Synthesis of Porous Carbon Hollow Particles from Polymer Hollow Particles Invited Reviewed

Yusuke Kawai, Tetsuya Yamamoto

Journal of the Society of Powder Technology, Japan Vol. 57 ( 8 ) page： 412 - 416 2020.8

Making hollows using nitrogen gas emitted by the decomposition of VAm-110 in polystyrene particles Reviewed

Tetsuya Yamamoto, Kazuya Tsutsumi, Yusuke Kawai

Polymer Vol. 202 page： 122761 - 122761 2020.8

Relationship between dispersion-forming capability of poly(4-vinylaniline) colloids and antimicrobial activity Reviewed

Tetsuya Yamamoto, Ryo Furuta, Kenji Arakawa, Aiko Teshima

Colloids and Surfaces A: Physicochemical and Engineering Aspects Vol. 596 page： 124736 - 124736 2020.7

Improved metal-resin adhesion via electroplating-induced polymer particle adsorption Reviewed

Yusuke Ota, Tetsuya Yamamoto

Surface and Coatings Technology Vol. 388 page： 125591 - 125591 2020.4

Synthesis of porous carbon hollow particles maintaining their structure using hyper-cross-linked Poly(St-DVB) hollow particles Reviewed

Yusuke Kawai, Tetsuya Yamamoto

Advanced Powder Technology Vol. 31 ( 2 ) page： 614 - 620 2020.2

自動車用金属部材/CFRTP界面の接着向上技術の開発

山本徹也

公益財団法人天野工業技術研究所平成30年度年次報告 page： 88 - 94 2019.12

Controlling Porous Hollow Silica Particles through Soap-free Emulsion Polymerization with Polymer Core Particles Reviewed

Tetsuya Yamamoto, Yuya Takahashi

Chemistry Letters Vol. 48 ( 10 ) page： 1229 - 1231 2019.10

Influence of the size of polystyrene synthesized through soap-free emulsion polymerization on antimicrobial activity Reviewed

Tetsuya Yamamoto, Kenji Arakawa, Ryo Furuta, Aiko Teshima

Materials Today Communications Vol. 20 page： 100572 - 100572 2019.9

Synthesis of dimpled and submicron-sized polymer particles of different morphologies using free micromixer Reviewed

Yusuke Kawai, Tetsuya Yamamoto

Colloid and Interface Science Communications Vol. 32 page： 100193 - 100193 2019.9

Development of Surface Control Technique for Enhancement and Recycle of CFRTP

Vol. 72 page： 190 - 191 2019.5

Preparation of PVA/Polymer Colloid nanocomposite Hydrogel Using PS-PNVA Particles Reviewed

Naoya Toyoda, Tetsuya Yamamoto, Kenji Arakawa, Aiko Teshima

Chemistry Letters Vol. 48 ( 4 ) page： 378 - 381 2019.4

Effect of Initiator Charge on Dispersion Stability of Polymer Particles Formed by Soap-free Emulsion Polymerization of 4-Vinylaniline or 4-Vinylpyridine Reviewed

Tetsuya Yamamoto, Ryo Furuta, Yusuke Kawai

Chemistry Letters Vol. 48 ( 3 ) page： 208 - 210 2019.3

Synthesis of Polystyrene@Silica Particles through Soap-Free Emulsion Polymerization and Sol-Gel Reaction on Polymer Surfaces Reviewed

T. Yamamoto, and Y. Takahashi

Advanced Powder Technology Vol. 30 ( 1 ) page： 214 - 218 2019.1

界面特性を強化した熱可塑性炭素繊維強化プラスチックの作製

山本徹也

東燃ゼネラル石油研究奨励財団研究報告書 Vol. 20 page： in press 2018.12

Antimicrobial activities of low molecular weight polymers synthesized through soap-free emulsion polymerization Reviewed

Yamamoto, Tetsuya, Arakawa, Kenji, Takahashi, Yuya, Sumiyoshi, Miho

European Polymer Journal Vol. 109 page： 532-536 2018.12

Antimicrobial activities of polymers synthesized through soap-free emulsion polymerization using a cationic initiator and styrene derivative monomers Reviewed

Yamamoto, Tetsuya; Arakawa, Kenji; Furuta, Ryo; Teshima, Aiko

Chemistry Letters Vol. 47 ( 11 ) page： 1402-1404 2018.11

Dispersion of carbon nanofibers modified with polymer colloids to enhance mechanical properties of PVA nanocomposite film Reviewed

Toyoda Naoya, Yamamoto Tetsuya

Colloids and Surfaces a-Physicochemical and Engineering Aspects Vol. 556 page： 248 - 252 2018.11

Design of polymer particles maintaining dispersion stability for the synthesis of hollow silica particles through sol-gel reaction on polymer surfaces Reviewed

Tetsuya Yamamoto, Yuya Takahashi

Colloids and Surfaces A: Physicochemical and Engineering Aspects Vol. 553 page： 66 - 70 2018.9

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier B.V.

To synthesize polystyrene-silica core-shell particles and silica hollow particles, soap-free emulsion polymerization was carried out using styrene and N-vinylacetamide (NVA), and the Stöber method using tetraethyl orthosilicate (TEOS) was performed on the polymer particle surfaces. Here, NVA acts as a stabilizer for the polymer colloids, maintaining dispersion stability by synthesizing hydration layers even when the electrostatic adsorption of TEOS had occurred, and as a catalyst for the sol-gel reaction. NVA was polymerized by the cationic initiator located on the surface of the polystyrene particles to maintain dispersion stability by a steric effect. Therefore, the sol-gel reactions proceeded more efficiently on the surface of polymer particles, facilitated by the much larger surface area. Finally, the polymer core was removed by heating to prepare highly monodisperse silica hollow particles.

DOI： 10.1016/j.colsurfa.2018.05.036

Effect of the surface properties of particle on the classification performance of a dry-cyclone Reviewed

Development of Techniques for Dispersion of Hydrophobic Powder in Water Using Particles

Vol. 25 page： 113-118 2018.5

Tetsuya Yamamoto, Motoharu Higashino

Particulate Science and Technology Vol. 36 ( 1 ) page： 46 - 49 2018.1

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Taylor and Francis Inc.

The purpose of the present study was to investigate the effect of the surface properties of silica particles on the classification performance of a dry-cyclone. As a result, it was clear that the separation force between the surface of particle and the silicon was decreased by the AFM measurement when the surface of the silica particles could be modified with ethanol or acetone treatment. Fine particles in the original silica particles with the treatments were easily collected by the filter in a dry-cyclone system
hence, the particle classification performance was enhanced.

DOI： 10.1080/02726351.2016.1205691

Enhancement of surface adhesion between thermoplastic resin and carbon fiber using polymer colloids Reviewed

Enhancement of mechanical properties of carbon fiber reinforced thermoplastic using colloidal techniques Reviewed

Tetsuya Yamamoto, Katsumasa Uematsu, Syo Yabushita

Procedia Manufacturing Vol. 15 page： 1738 - 1745 2018

炭素繊維強化熱可塑性樹脂の高性能化を実現する界面制御技術の開発

山本徹也

新東技報 Vol. 35 page： 70-72 2017.12

Tetsuya Yamamoto, Katsumasa Uematsu, Toshihira Irisawa, Yasuhiro Tanabe

The Journal of Adhesion Vol. 93 ( 12 ) page： 943 - 948 2017.10

Improved mechanical properties of PMMA composites: Dispersion, diffusion and surface adhesion of recycled carbon fiber fillers from CFRP with adsorbed particulate PMMA Reviewed

Tetsuya Yamamoto, Yuta Makino, Katsumasa Uematsu

Advanced Powder Technology Vol. 28 ( 10 ) page： 2774 - 2778 2017.10

In-situ Adsorption of Polymer Particles on Multi-wall Carbon Nanotubes Using Colloidal Techniques Reviewed

Tetsuya Yamamoto, Naoya Toyoda

Colloids and Interface Science Communications Vol. 20 page： 1 - 4 2017.9

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier B.V.

A novel technique for the adsorption of polymer particles on carbon nanotubes was developed. First, the surfaces of multi-wall carbon nanotubes (MWCNTs) were coated with poly(N-vinyl acetamide) (PNVA) to confer them hydrophilicity together with good dispersion stability in water owing to a steric effect between the hydration layers. Second, the hydrophilic MWCNTs were covered with polymethyl methacrylate (PMMA) particles bearing positive charges—synthesized using V-50—through electrostatic interactions. These polymers were obtained by soap-free emulsion polymerization. The in-situ adsorption of PMMA particles on surface MWCNTs were attributed to the hydration layers of the modified MWCNTs, and electrostatic interactions between PMMA particles and the modified MWCNTs. It can be expected that the PMMA particles adsorbed on the carbon nanotubes hold the potential to serve as glue between carbon nanotube and PMMA in the composite.

DOI： 10.1016/j.colcom.2017.07.003

Synthesis and Electrical Properties of Composite Films Comprising Polymer Particles and Carbon Nanotubes Reviewed

Tetsuya Yamamoto, Kan Kawaguchi

Colloids and Interface Science Communications Vol. 20 page： 5 - 8 2017.9

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier B.V.

In the present study, composite films were synthesized from composite polymer particles prepared with multi-wall carbon nanotubes (MWCNTs) by in situ polymerization. Because one of the advantages of MWCNTs compared to other preparation methods is high electrical conductivity, the electrical properties of the composite films were evaluated by the direct current two-terminal method. As a result, the composite film prepared by MWCNTs had conductive paths and showed higher conductivity even at lower mass fraction of MWCNTs compared with the previous works to keep transparency. This method was shown to decrease the mass fractions of MWCNTs and increase the transparency of the composite films.

DOI： 10.1016/j.colcom.2017.08.001

Synthesis of composite polymer particles with carbon nanotubes and evaluation of their mechanical properties Reviewed

Tetsuya Yamamoto, Kan Kawaguchi

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS Vol. 529 page： 765 - 770 2017.9

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

In the present study, a method for synthesizing composite polymer particles with multi-wall carbon nanotubes (MWCNTs) was developed, and the particles' mechanical properties were evaluated. First, the surfaces of MWCNTs were modified by acids to increase their hydrophilicity, resulting in surface-active MWCNTs. Then, a Pickering emulsion was formed using liquid benzyl methacrylate monomer and the surface-active MWCNTs. The surface charge of the surface-active MWCNTs greatly influenced the surface coverage and size of the composite particles. Furthermore, when untreated MWCNTs were added to the monomer phase, surface coverage of the resulting particles was enhanced because MWCNTs on the surface of the particles interacted with MWCNTs incorporated inside the particles, thus preventing the surface-active MWCNTs on the surface from being released into the bulk. As a result, the mechanical properties of the composite polymer particles were successfully improved because the incorporated MWCNTs worked well as fillers.

DOI： 10.1016/j.colsurfa.2017.05.075

Anomalous particle through soap-free emulsion polymerization of styrene using oil-soluble initiator Reviewed

Tetsuya Yamamoto, SeulChan Kim

JOURNAL OF POLYMER RESEARCH Vol. 24 ( 9 ) page： 149 2017.8

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

One of oil-soluble initiators, VF-096, might work as cross-linker. This initiator would enable to synthesize the particle with cross-linking, which was involved with the particle morphology. Soap-free emulsion polymerization of styrene using this initiator was carried out to develop the method to control the particle morphology in one batch system. As a result, it was found that anomalous particle was generated without stirring and the particle morphology changed to be spherical by increasing shear stress through the stirring. One of the origins of the anomalous particle was the phase separation of the water in the particle and release of it from inside of the particle to the bulk.

DOI： 10.1007/s10965-017-1316-2

Controlling the particle cut size of a dry cyclone using acetone Reviewed

Tetsuya Yamamoto, Motoharu Higashino

Particulate Science and Technology Vol. 35 ( 2 ) page： 214 - 218 2017.3

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Taylor and Francis Inc.

In this study, we investigated the interaction between particles and the wall in the presence of mist to improve the particle classification performance of a dry cyclone. The interaction between a silica particle and a mica surface in the presence of a flowing acetone mist was measured by performing atomic force microscopy (AFM), which showed that an attractive force was generated and became stronger as time passed while acetone mist was supplied to the system, probably because of static electricity. In a dry cyclone system, this attractive force could enhance the classification performance. In particular, when acetone mist was supplied into the cyclone from the upper part of the dust box at higher flow rates, the classification performance was enhanced. Because acetone is highly volatile and has a low viscosity, the classification performance was improved by the evaporated acetone even when a cyclone with a dust box filled with acetone was used instead of a nozzle supplying the mist. In this case, the ratio of the mass of the particles collected by the upper part of the cyclone to the total mass of the feed powder was increased, probably because of the attractive force between the silica particles and the wall of the cyclone. Moreover, the cut size of the dry cyclone could be controlled by changing the amount of acetone in the dust box of the cyclone.

DOI： 10.1080/02726351.2016.1150370

Synthesis of hydrocolloid through polymerization of styrene and N-vinyl acetamide by AIBN Reviewed

CFRTPの高性能化を実現するコロイド技術 Invited

山本徹也

化学装置 Vol. 59 ( 3 ) page： 45 - 48 2017.3

Tetsuya Yamamoto, Yuya Takahashi

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS Vol. 516 page： 80 - 84 2017.3

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

The soap-free emulsion polymerization of styrene with hydrophilic monomer, N-vinyl acetamide (NVA), using oil-soluble initiator was carried out to synthesize polymeric particles with good dispersion stability and improve the polymer yield. As a result, it was found that the polymer yield and dispersion stability were enhanced by the promotion of polymerization by the dissolved monomers and hydrogen bonding between NVA on the particle surface and water molecules in the bulk. Accordingly, this polymer colloid showed the nature of hydrocolloid by their hydration layers because its dispersion stability was kept even when the electrolytes were added to the system. In the conventional soap-free emulsion polymerization, the counter ions including the water-soluble initiators were remained in the water phase. However, because all of chemical components in the present study were consumed for the polymerization, the impurities except polymers were hardly remained in the bulk. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.colsurfa.2016.12.023

Controlling of the interfacial shear strength between thermoplastic resin and carbon fiber by adsorbing polymer particles on carbon fiber using electrophoresis Reviewed

炭素繊維強化熱可塑性樹脂の高性能化を実現するコロイド技術 Invited Reviewed

山本徹也、上松克匡、入澤寿平、田邊靖博

粉体工学会誌 Vol. 53 ( 12 ) page： 786 - 791 2016.12

Tetsuya Yamamoto, Katsumasa Uematsu, Toshihira Irisawa, Yasuhiro Tanabe

COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING Vol. 88 page： 75 - 78 2016.9

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

In order to control the interfacial adhesion between carbon fibers and thermoplastic resins, poly(methyl methacrylate) (PMMA) particles have been adsorbed on the carbon fiber surfaces using an electrophoresis process. The amount of PMMA particles adsorbed on the modified carbon fibers was varied using the electrophoresis technique performed in polymer colloids for a short time. Additionally, the interfacial shear strength between the modified carbon fiber and the resin was controlled by a modification of the present process. An improved interaction and a strengthened surface adhesion between the carbon fiber coated with particles and the PMMA resin were observed. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.compositesa.2016.05.021

Particle size control in the soap-free emulsion polymerization of styrene by an oil-soluble initiator with a weakly acidic water-soluble initiator Reviewed

Tetsuya Yamamoto, Kan Kawaguchi, Yuya Takahashi

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS Vol. 502 page： 1 - 5 2016.8

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

The soap-free emulsion polymerization of styrene by an oil-soluble initiator, 2,2'-azobis(2-methylpropionitrile) (AIBN), with a water-soluble initiator, 4,4'-azobis(4-cyanovaleric acid) (V-501), was conducted in water to control the size of the synthesized polymeric particles. The particle size and surface potential were monitored as concentration of V-501 used for the polymerization was varied. When the V-501 concentration was increased, the particle size increased because V-501 was a weak acid and reduced the surface potential, thereby promoting particle growth through coagulation. Additionally, V-501 can also function as a radical initiator, increasing the efficiency of the polymerization reaction and, thus, the number concentration of the particles. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.colsurfa.2016.04.048

Effect of the Amount of pi Electrons in Aromatic Monomer on the Surface Potential of Polymeric Particles Obtained through Soap-free Emulsion Polymerization Using AIBN Reviewed

Relationship between Surface Potential and Particle Size in Soap-free Emulsion Copolymerization of Styrene and Methyl Methacrylate using a Water- or Oil-soluble Initiator Reviewed

Colloid & Polymer Science Vol. 294 page： 281 - 284 2016.2

Tetsuya Yamamoto

CHEMISTRY LETTERS Vol. 44 ( 11 ) page： 1555 - 1556 2015.11

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

The surface potential of polymeric particles obtained through soap-free emulsion polymerization using an oil-soluble initiator, 2,2'-azobis(2-methylpropionitrile) (AIBN), depended on the monomer used in the polymerization. Changing the amount of it electrons in the aromatic monomer enabled control of the surface potential of the synthesized particles. It was found that the negative charges of the synthesized particles were strengthened for their sizes to be reduced gradually as the amount of it electrons in the monomer was increased.

DOI： 10.1246/cl.150759

Effect of Counter Ionic Radius in Initiator on Particle Size in Soap-free Emulsion Polymerization of Styrene Reviewed

Tetsuya Yamamoto, Taichi Yokoyama

CHEMISTRY LETTERS Vol. 44 ( 6 ) page： 824 - 825 2015.6

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

Soap-free emulsion polymerization of styrene was carried out to synthesize particles with the size under 100 nm. Changing the concentration of initiator, VA-044, enabled us to control the size under 100 nm in soap-free emulsion polymerization of styrene. Furthermore, making the counter ion radius in initiator smaller was effective for reducing the size of particles in the polymerization.

DOI： 10.1246/cl.150148

Effect of electrolyte species on size of particle through soap-free emulsion polymerization of styrene using AIBN and electrolyte Reviewed

Tetsuya Yamamoto, Kan Kawaguchi

COLLOID AND POLYMER SCIENCE Vol. 293 ( 3 ) page： 1003 - 1006 2015.3

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

The addition of electrolyte to a soap-free emulsion polymerization using oil-soluble initiator, 2,2'-azobis(2-methylpropionitrile) (AIBN), was useful for production of the micron-sized polystyrene particle. To investigate the effect of electrolyte species on particle size, we focus on the counter ion and ionic radius of the cation during the synthesis of the particle. As a result, because the order of acid dissociation constant of the acid was HCl < HNO3 < CH3COOH, the suspension using chloride salt has lower pH and included the larger particles due to the coagulation growth process. Cation with a larger ionic radius could promote the particle growth strongly because its hydration was so weaker that it had the ability to reduce the thickness of the electrical double layer of negatively charged polystyrene particle. In summary, the addition of strongly acidic salt with larger cationic radius to the polymerization was efficient for making the size of polystyrene particle larger.

DOI： 10.1007/s00396-015-3511-1