Hisashi KOKUBO

Born in 1974
B. Eng. (Undergraduate)	Tokyo University of Science (1998)
D. Eng. (PhD)	Tokyo Institute of Technology (2003)
PD	Research Fellow of the Japan Society for the Promotion of Science (JSPS) (2003−2004)
Research Associate	Yokohama National University (Sep. 2004−Present)
Visit Researcher	Monash University, AUS (2013−2014)
Research Topics	• Polymer Chemistry, Polymer Science • Electrochemistry
Affiliated Academic Society	• The Chemical Society of Japan • The Society of Polymer Science, Japan • The Electrochemical Society of Japan • Ionic Liquid Research Association, Japan
Management of International & Domestic Conferences	• The 16^th International Symposium on Polymer Electrolytes (ISPE-16) June 24^th−29^th, 2018 @Yokohama Symposia (Yokohama) Organizing Committee.
	• The 82^nd ESC Japan Spring meeting Mar. 15^th−17^th, 2015@ Yokohama National University Organizing Committee.
	• The 6^th International Symposium on Organic Photochromism (ISOP2010) Oct. 17^th−21^st, 2010 @Nisseki Yokohama Hall (Yokohama). Organizing Committee.
	• International Conference on Science and Technology of Synthetic Metals 2010 (ICSM2010) Jul. 4^th−9^th, 2010 @Kyoto International Conference Center (Kyoto). National organizing Committee & Program Committee.
	• The 4^th International Conference on Polymer Batteries and Fuel Cells (PBFC2009) Aug. 2^nd−6^th, 2009 @Yokohama Symposia (Yokohama). Local Executive Committee.
	• 2^nd International Congress on Ionic Liquids (COIL-2) Aug. 5^th−10^th, (2007) @Pacifico Yokohama (Yokohama). Local Executive Committee.
	• International Symposium of Task-Specific Ionic Liquids Aug. 3^rd−4^th, (2007) @Keio University (Yokohama). Organizing Committee.
Award	Award for Encouragement of Research in Polymer Science; The Society of Polymer Science, Japan (2009).

Peer-reviewed original paper

[As of 12-Feb-2019]

(Google Scholar)

61	“Polymer Electrolytes Based on Homogeneous Poly(ethylene glycol) Network And Their Application to Polymer Actuators” R. Shioiri, H. Kokubo, T. Horii, Y. Kobayashi, K. Hashimoto, K. Ueno, M. Watanabe Electrochim. Acta, 298, 866−873 (2019).
60	“Viscoelastic Change of Block Copolymer Ion Gels in a Photo-switchable Azobenzene Ionic Liquid Triggered by Light” C. Wang, K. Hashimoto, R. Tamate, H. Kokubo, K. Morishima, X. Li, M. Shibayama, F. Lu, T. Nakanishi, M. Watanabe Chem. Commun., 55, 1710−1713 (2019).
59	“Solid Polymer Electrolytes Based on Polystyrene−Polyether Block Copolymers having Branched Ether Structure” H. Kokubo, E. Nakazawa, M. Watanabe Polym. Adv. Technol., 30, 736−742 (2019).
58	“Polystyrene-Polyether Block Copolymers having Brunched Ether Structure and Their Fundamental Properties” A. Saruwatari, K. Hashimoto, R. Tamate, R. Usui, H. Kokubo, M. Watanabe Aust. J. Chem.,72, 155−159 (2019).
57	“Photo-healable ion gels based on the reversible dimerization of anthracene” A. Saruwatari, R. Tamate, H. Kokubo, M. Watanabe Chem. Commun., 54, 13371−13374 (2018).
56	“Photo/thermoresponsive ABC triblock copolymer-based ion gels: Photoinduced structural transitions” R. Tamate, R. Usui, K. Hashimoto, Y. Kitazawa, H. Kokubo, M. Watanabe Soft Matter, 14, 9088−9095 (2018).
55	“Ionic Polymer Actuators Using Poly(ionic liquid) Electrolytes” H. Kokubo, R. Sano, K. Murai, S. Ishii, M. Watanabe Eur. Polym. J., 106, 266−272 (2018).
54	“Photocurable ABA Triblock Copolymer-based Ion Gels Produced via Photodimerization of Coumarins” R. Tamate, T. Ueki, A. M. Akimoto, R. Yoshida, T. Oyama, H. Kokubo, M. Watanabe RSC Advances, 8, 3418−3422 (2018).
53	“Polymer Electrolytes Containing Solvate Ionic Liquids: A New Approach to Achieve High Ionic Conductivity, Thermal Stability, and a Wide Potential Window” Y. Kitazawa, K. Iwata, R. Kido, S. Imaizumi, S. Tsuzuki, W. Shinoda, K. Ueno, T. Mandai, H. Kokubo, K. Dokko, M. Watanabe Chem. Mater., 30, 252−261 (2018).
52	“Controlled Sol-Gel Transitions of a Thermoresponsive Polymer in a Photoswitchable Azobenzene Ionic Liquid as a Molecular Machine” C. Wang, K. Hashimoto, R. Tamate, H. Kokubo, M. Watanabe Angew. Chem. Int. Ed., 57, 227−230 (2018).
51	“Thermo-sensitive Phase Separation Behavior of Poly(benzyl methacrylate)/ Solvate Ionic Liquid Solutions” Y. Kobayashi, Y. Kitazawa, K. Hashimoto, T. Ueki, H. Kokubo, M. Watanabe Langmuir, 33, 14105−14114 (2017).
50	“Physicochemical Characterization of a Photoinduced Sol−Gel Transition of an Azobenzene-Containing ABA Triblock Copolymer/Ionic Liquid System” X. Ma, R. Usui, Y. Kitazawa, R. Tamate, H. Kokubo, M. Watanabe Macromolecules, 50, 6788−6795 (2017).
49	“Micellization/Demicellization Self-Assembly Change of ABA Triblock Copolymers Induced by a Photoswitchable Ionic Liquid with a Small Molecular Trigger” C. Wang, K. Hashimoto, J. Zhang, Y. Kobayashi, H. Kokubo, M. Watanabe Macromolecules, 50, 5377−5384 (2017).
48	“Tetra-PEG Network Containing Ionic Liquid Synthesized via Michael Addition Reaction and Its Application to Polymer Actuator” S. Ishii, H. Kokubo, K. Hashimoto, S. Imaizumi, M. Watanabe Macromolecules, 50, 2906−2915 (2017).
47	“A Polymer Electrolyte Containing Solvate Ionic Liquid with Increased Mechanical Strength Formed by Self-assembly of ABA-type Ionomer Triblock Copolymer” T. Kawazoe, K. Hashimoto, Y. Kitazawa, H. Kokubo, M. Watanabe Electrochim. Acta, 235, 287−294 (2017).
46	“From Macromolecular to Small-molecular Triggers: Facile Method Towards Photoinduced LCST Phase Behavior of Thermoresponsive Polymers in Mixed Ionic Liquids Containing an Azobenzene Moiety” C. Wang, X. Ma, Y. Kitazawa, Y. Kobayashi, S. Zhang, H. Kokubo, M. Watanabe Macromol. Rapid Commun., 37, 1960−1965 (2016).
45	“Self-assembly of Polyether Diblock Copolymers in Water and Ionic Liquids” Y. Kobayashi, Y. Kitazawa, T. Komori, K. Ueno, H. Kokubo, M. Watanabe Macromol. Rapid Commun., 37, 1207−1211 (2016).
44	“Photo-healable Ion Gel with Improved Mechanical Properties Using a Tetra-Arm Diblock Copolymer Containing Azobenzene Groups” X. Ma, R. Usui, Y. Kitazawa, H. Kokubo, M. Watanabe Polymer, 78, 42−50 (2015).
43	“Temperature and Light-Induced Self-Assembly Changes of a Tetra-Arm Diblock Copolymer in an Ionic Liquid” X. Ma, R. Usui, Y. Kitazawa, H. Kokubo, M. Watanabe Polym. J., 47, 739−749 (2015).
42	“Effects of Carbon Electrode Materials on Performance of Ionic Polymer Actuators Having Electric Double-Layer Capacitor Structure” H. Kokubo, T. Honda, S. Imaizumi, K. Dokko, M. Watanabe Electrochemistry, 81, 849− 852 (2013).
41	“Thermoreversible Nanogel Shuttle between Ionic Liquid and Aqueous Phases” T. Ueki, S. Sawamura, Y. Nakamura, Y. Kitazawa, H. Kokubo, M. Watanabe Langmuir, 29, 13661−13665 (2013).
40	“Printable Polymer Actuators from Ionic Liquid, Soluble Polyimide, and Ubiquitous Carbon Materials” S. Imaizumi, Y. Ohtsuki, T. Yasuda, H. Kokubo, M. Watanabe ACS Appl. Mater. Interfaces, 5, 6307−6315 (2013).
39	“Alternating Copolymer Based on Sulfonamide-Substituted Phenylmaleimide and Vinyl Monomers as Polymer Electrolyte Membrane” T. Yasuda, Y. Okimura, A. Oishi, H. Kokubo, M. Watanabe J. Polym. Sci.: A: Polym. Chem., 51, 2233−2242 (2013).
38	“Driving Mechanisms of Ionic Polymer Actuators Having Electric Double Layer Capacitor Structures” S. Imaizumi, Y. Kato, H. Kokubo, M. Watanabe J. Phys. Chem. B, 116, 5080−5089 (2012).
37	“Polymer Actuators Using Ion-Gel Electrolytes Prepared by Self-Assembly of ABA-Triblock Copolymers“ S. Imaizumi, H. Kokubo, M. Watanabe Macromolecules, 45, 401−409 (2012).
36	“p-Conjugated Polymers, (Th(R)-CH=CH-Th(R))n (Th(R) = 3-Alkylthiophene-2,5-diyl; R = Octyl, Decyl, and Dodecyl): Preparation of Dibromo Monomers and the Polymers“ T. Yamamoto, A. Kumagai, H. Kokubo, Y. Nakamura Bull. Chem. Soc. Jpn., 84, 1291−1293 (2011).
35	“Structural Effects of Polyethers and Ionic Liquids in Their Binary Mixtures on Lower Critical Solution Temperature Liquid-Liquid Phase Separation” K. Kodama, R. Tsuda, K. Niitsuma, T. Tamura, T. Ueki, H. Kokubo, M. Watanabe Polym. J., 43, 242−248 (2011).
34	“Photoisomerization-Induced Tunable LCST Phase Separation of Azobenzene-Containing Polymers in an Ionic Liquid“ T. Ueki, A. Yamaguchi, N. Ito, K. Kodama, J. Sakamoto, K. Ueno, H. Kokubo, M. Watanabe Langmuir, 25, 8845−8848 (2009).
33	“Two-Photon Excited States in Charge-Transfer Type Conjugated Polymers” H. Kishida, K. Hirota, H. Okamoto, H. Kokubo, T. Yamamoto Synth. Met., 159, 868−870 (2009).
32	“Development of a Soft Actuator Using a Photocurable Ionic Gel” S. Saito, Y. Katoh, H. Kokubo, M. Watanabe, S. Maruo J. Micromech. Microengin., 19, 035005/1−035005/5 (2009).
31	“Lower Critical Solution Temperature Phase Behavior of Linear Polymers in Imidazolium-Based Ionic Liquids: Effects of Structural Modifications” K. Kodama, H. Nanashima, T. Ueki, H. Kokubo, M. Watanabe Langmuir, 25, 3820−3824 (2009).
30	“Anionic Polymerization of Methyl Methacrylate in an Ionic Liquid” H. Kokubo, M. Watanabe Polym. Adv. Technol., 19, 1441−1444 (2008).
29	“LCST-Type Liquid-Liquid Phase Separation Behaviour of Poly(ethylene oxide) Derivatives in an Ionic Liquid” R. Tsuda, K. Kodama, T. Ueki, H. Kokubo, S. Imabayashi, M. Watanabe Chem. Commun., 2008, 4939−4941.
28	“Continuous Control of Third-Order Optical Nonlinearity in Charge-Transfer Type Conjugated Polymers” H. Kishida, K. Hirota, H. Okamoto, H. Kokubo, T. Yamamoto Appl. Phys. Lett., 39, 033309/1−033309/3 (2008).
27	“p-Doping Behavior of Oligothiophenes and Effect of Trifluoroacetic Acid Concentration” M. Imit, T. Yamamoto, H. Kokubo, P. Imin Cailiao Kexue Yu Gongcheng Xuebao, 25, 40−42, (2007).
26	“Effect of Core-Shell Micelle Formation on the Redox Properties of Phenothiazine-Labeled Poly(ethyl glycidyl ether)-block-Poly(ethylene oxide)” R. Tsuda, S. Kaino, H. Kokubo, S. Imabayashi, M. Watanabe Colloid and Surfaces B, Biointerfaces, 56, 255−259 (2007).
25	“Electron-Nuclear Double-Resonance Observation of Spatial Extent of Polarons in Polythiophene and Poly(3-alkylthiophene)” S. Kuroda, K. Marumoto, T. Sakanaka, N. Takeuchi, Y. Shimoi, S. Abe, H. Kokubo, T. Yamamoto Chem. Phys. Lett., 435, 273−277 (2007).
24	“Synthesis of New Thiophene-Based p-Conjugated Polymers for Investigation of Molecular Alignment on the Surface of Platinum Plate” H. Kokubo, T. Sato, T. Yamamoto Macromolecules, 39, 3956−3963 (2006).
23	“Specific charge transport in ionic liquids and ion gels and the importance in material science.” R. Kawano, H. Tokuda, T. Katakabe, H. Nakamoto, H. Kokubo, S. Imabayashi, M. Watanabe Kobunshi Ronbunsyu, 63, 31−40 (2006).
22	“Third-Order Optical Nonlinearity in Regio-Controlled Polythiophene Films.” H. Kishida, K. Hirota, T. Wakabayashi, H. Okamoto, H. Kokubo, T. Yamamoto Appl. Phys. Lett., 87, 121902/1−121902/3 (2005).
21	“Synthesis of 3-Alkynyl-2,5-dibromothiophene and 3,3’Dialkynyl-5,5’-dibromo-2,2’-bithiophene as the Starting Compounds for p-Conjugated Polymer” T. Sato, H. Kokubo, H. Fukumoto, T. Yamamoto Bull. Chem. Soc. Jpn., 78, 1368−1370 (2005).
20	“Molecular Alignment of n-Alkanes and Head-to-Tail-Type Poly(3-alkylthiophene) on Substrates: Study with Films Prepared by Casting and Vacuum Deposition” H. Kokubo, T. Sato, T. Yamamoto Mol. Cryst. Liq. Cryst., 432, 83−100 (2005).
19	“Third-Order Nonlinear Optical Spectroscopy in Charge-Transfer Type Conjugated Polymers” H. Kishida, K. Hirota, T. Wakabayashi, H. Okamoto, B.-L. Lee, H. Kokubo, T. Yamamoto Synth. Met., 153, 141−144 (2005).
18	“Heteroaromatic and Aromatic Conjugated Polymers Synthesized by Organometallic Coupling - Preparation and Selected Electrochemical Properties.” T. Yamamoto, H. Kokubo Electrochim. Acta, 50, 1453−1460 (2005).
17	“Third-Order Optical Nonlinearity in Charge-Transfer Type Conjugated Polymer” H. Kishida, K. Hirota, T. Wakabayashi, B.-L. Lee, H. Kokubo, T. Yamamoto, H. Okamoto Phys. Rev. B, 70, 115205−1/5 (2004).
16	“Alignment and Field-effect Transistor Behavior of an Alternative p-Conjugated Copolymer of Thiophene and 4-Alkylthiazole” T. Yamamoto, H. Kokubo, M. Kobashi, Y. Sakai Chem. Mater., 16, 4616−4618 (2004).
15	“Electrochemical Behavior of Poly(3-hexylthiophene). Controlling Factors of Electric Current in Electrochemical Oxidation of Poly(3-hexylthophene)s in a Solution” T. Yamamoto, Y. Honda, T. Sato, H. Kokubo Polymer, 45, 1735−1738 (2004).
14	“Preparation of New Main-Chain Type Polyanthraquinones. Chemical Reactivity, Packing Structure, Piezochromism, Conductivity, and Liquid Crystalline and Photonic Properties of the Polymers” T. Yamamoto, Y. Muramatsu, B.-L. Lee, H. Kokubo, S. Sasaki, M. Hasegawa, T. Yagi, K. Kubota Chem. Mater., 15, 4384−4393 (2003).
13	“Purification of Head-to-Tail-Type Regioregular Poly(3-hexylthiophene), HT-P3HexTh, and Investigation of the Effects of Polymer Purity on the Performance of Organic Field-Effect Transistors” H. Kokubo, T. Yamamoto, H. Kondo, Y. Akiyama, I. Fujimura Jpn. J. Appl. Phys., 42, 6627−6628 (2003).
12	“Copolymers of Thiophene and Thiazole. Regioregulation in Synthesis, Stacking Structure, and Optical Properties” T. Yamamoto, M. Arai, H. Kokubo, S. Sasaki Macromolecules, 36, 7986−7993 (2003).
11	“Synthesis of a New Thiophene/Quinoxaline CT-Type Copolymer with High Solubility and Its Basic Optical Properties” T. Yamamoto, B.-L. Lee, H. Kokubo, H. Kishida, K. Hirota, T. Wakabayashi, H. Okamoto Macromol. Rapid Commun., 24, 440−443 (2003).
10	“Comparison of the Organometallic Copolymerizations of Thiophene with 4-Alkylthiazole and 3-Alkylthiophene: The Control of Regioregularity in the Copolymerization with 4-Alkylthiazole” T. Yamamoto, M. Arai, H. Kokubo, S. Sasaki J. Polym. Sci.: Part A: Polym. Chem., 41, 1449−1453 (2003).
9	“Molecular Alignment of Neutral and p-Doped Head-to-Tail Type Poly(3-hexylthiophene-2,5-diyl) and n-Alkanes on the Surface of Substrates” T. Yamamoto, H. Kokubo Mol. Cryst. Liq. Cryst., 381, 113−119 (2002).
8	“Preparation, Structure and Conduction Properties of SeCN-Containing Mixed Anion TTF Conductors” M. Mizuno, H. Kokubo, K. Honda J. Mater. Chem., 11, 2192−2198 (2001).
7	“Molecular Alignment of Head-to-Tail-Type Poly(3-hexyl-thiophene-2,5-diyl) and Related Polymers and Compounds on Substrates” T. Yamamoto, H. Kokubo, T. Morikita J. Polym. Sci.: Part B: Polym. Phys., 39, 1713−1718 (2001).
6	“Organometallic Syntheses of Head-to-Head Poly(3-hexylthiophene) and Related Polymer with a Spacing Non-Substituted Thiophene Unit. Colloidal Solutions of the Polymers” H. Kokubo, T. Yamamoto Macromol. Chem. Phys., 202, 1031−1034 (2001).
5	“Electrochemical Deposition of Regioregular Head-to-Tail Poly(3-hexylthiophene-2,5-diyl) and Characterization of the Obtained Film” H. Kokubo, S. Kuroda, S. Sasaki, T. Yamamoto Jpn. J. Appl. Phys., 40, L228−L230 (2001).
4	“p-Conjugated Polymers Prepared by Organometallic Polycondensation and Metal Complexes of the Polymers” T. Yamamoto, H. Nakajima, N. Hayashida, K. Shiraishi H. Kokubo Polym. Adv. Technol., 11, 658−664 (2000).
3	“Selective Stacking of HT-Poly(3-n-alkylthiophene-2,5-diyl)s in Mixed Systems” T. Yamamoto, H. Kokubo J. Polym. Sci.: Part B: Polym. Phys., 38, 84−87 (2000).
2	“Electrochemical Deposition of Films of p-Doped Regioregular Poly(3-hexylthiophene-2,5-diyl)” T. Yamamoto, H. Kokubo Chem. Lett., 1925−1926 (1999).
1	“Preparation and Properties of Mixed Anion TTF Conductors“ M. Mizuno, K. Honda, H. Nakayama, H. Kokubo, T. Uchida Synth. Met., 103, 2138−2139 (1999).

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International Conference

13	“Development of Polymer Electrolytes Consisting of Homogeneous Polymer Network and Application to Polymer Actuator” H. Kokubo, R. Shioiri, S. Ishii, T. Horii, K. Hashimoto, K. Ueno, M. Watanabe The 15^th Pacific Polymer Conference (PPC-15), 12-Dec-2017, Xiamen International Conference & Exhibition Center, Xiamen, China.
12	“Development of polythiophene-PEO multi-block copolymer with electron and ion mixed-conduction” [Oral] H. Kokubo, T. Tani, S. Imaizumi, M. Watanabe Gelsympo2012, 11-Oct-2012, Tsukuba International Conference Center, Ibaraki, Japan.
11	“Preparation of Photochromic Ionic Liquids and Their Functionalization” [Poster] H. Kokubo, J. Sakamoto, K. Ueno, T. Ueki, M. Watanabe The 6^th International Symposium on Organic Photochromism (ISOP2010), 20-Oct-2010, Nisseki Yokohama Hall, Yokohama, Japan.
10	“Development of Ion Gel Electrolytes for Polymer Actuators” [Oral] H. Kokubo, S. Imaizumi, Y. Ohtsuki, M. Watanabe 12^th International Symposium on Polymer Electrolytes (ISPE12), 2-Sep-2010, Centro Culturale Altinate, Padova, Italy.
9	“Synthesis of Polyether-Grafted p-Conjugated Polymers and Solvent-Dependent and Thermosensitive Optical Properties” [Poster] H. Kokubo, D. Aoki, M. Furuya, M. Watanabe International Conference on Science and Technology of Synthetic Metals 2010 (ICSM2010), 8-July-2010, Kyoto International Conference Center, Kyoto, Japan.
8	“Development of a Polymer Actuator Utilizing Ion-Gel as Electrolyte” [Oral] H. Kokubo 3^rd International Symposium on “Next-Generation Actuators Leading Breakthroughs”, 26-Jan-2010, Tokyo Institute of Technology, Tokyo, Japan
7	“Synthesis, Optical and Solution Properties of Polyether-Grafted Polythiophenes Dissolved in Ionic Liquids” [Poster] H. Kokubo, M. Furuya, M. Watanabe 3^rd International Congress on Ionic Liquids (COIL-3), 2-June-2009, Cairns Convention Centre, QLD, Australia.
6	“Development of Ion-Gel for Polymer Actuator Utilizing Gelation Behavior of Ionic Liquids and ABA-Type Triblock Copolymer” [Oral] H. Kokubo, S. Imaizumi, M. Watanabe 2^nd International Symposium on “Next-Generation Actuators Leading Breakthroughs”, 17-Apr-2008, Makuhari Messe, Chiba, Japan.
5	“Performance of Ion-Gel Actuator Containing Ionic Liquids” [Oral, Invited] H. Kokubo, Y. Kato, T. Honda, M. Watanabe IUPAC 3^rd International Symposium on Novel Materials and Synthesis (NMS-III) & 17^th International Symposium on Fine Chemistry and Functional Polymers (FCFP-XVII), 19-Oct-2007, TianYi Hotel, Shanghai, China.
4	“Anionic Polymerization of PMMA in an Ionic Liquid” [Poster] H. Kokubo, M. Watanabe 2^nd International Congress on Ionic Liquids (COIL-2), 9-Aug-2007, Pacifico Yokohama, Yokohama, Japan.
3	“Molecular Alignment of π-Conjugated Polymers and Related Molecules on Substrates” [Poster] H. Kokubo, T. Yamamoto 5^th International Symposium ono Functional π-Electron Systems (Fπ5), June-2002, Ulm/Neu-Ulm, Germany.
2	“Organometallic Synthesis of Poly(3-hexylthiophene) Derivatives and Their Chemical Properties” [Poster & Short Oral Presentation] H. Kokubo, T. Yamamoto Post symposium of 11^th Organometallic Chemistry Directed Towards Organic Synthesis (Post-OMCOS XI), July-2001, Kyoto Terrsa, Kyoto, Japan.
1	“Electrochemical Deposition of Films of Regioregular Poly(3-hexylthiophene-2,5-diyl)” [Poster] H. Kokubo, T. Yamamoto Polycondensation2000, Sep-2000, Tokyo Institute of Technology, Tokyo, Japan.