研究者詳細 - 野呂　篤史

論文 - 野呂　篤史

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Effect of Alkyl Side Chain Length on Microscopic Structures and Mechanical Properties of Ionically-Functionalized Block Polymer-Based Thermoplastic Elastomers 査読有り国際誌 Open Access

Suzuki,K.; Kajita,T.; Ota,M.; Nakama, Y.; Tamura, Y.; Kinoshita, S.; Kato,D.; Oda, R.; Hashimoto,S.; Noro, A.

POLYMER CHEMISTRY accepted 巻 2025年4月

Polymer Electrolyte Membranes of Polystyrene with Directly Bonded Alkylenephosphonate Groups on the Side Chains 査読有り Open Access

Nakayama, T; Kajita, T; Nishimoto, M; Tanaka, H; Sato, K; Marium, M; Mufundirwa, A; Iwamoto, H; Noro, A

ACS APPLIED POLYMER MATERIALS 6 巻 ( 24 ) 頁： 15150 - 15161 2024年12月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：ACS Applied Polymer Materials

There is a pressing need for polymer electrolyte membranes (PEMs) for next-generation polymer electrolyte fuel cells that exhibit good conductivities even at temperatures >100 °C (the boiling point of water) under low humidity. Disadvantages of conventional PEMs made of sulfonic acid polymers generally include low conductivities and easy degradation at temperatures >100 °C under low humidity because of decomposition of the sulfonic acid groups. In this study, diethyl 4-(p-styryl)-1-butanephosphonate and poly(4-(p-styryl)-1-butanephosphonic acid) (sbPA) with phosphonic acid groups on the side chains through a hydrophobic alkylene spacer were synthesized by polymerization of the monomer and deprotection of the phosphonate esters. The sbPA membrane formed a phase-separated structure with a domain spacing of ∼2.5 nm between the hydrophobic part, consisting of phenylene groups and alkylene spacers in the polymer side chains, and the hydrophilic part of the phosphonic acid groups. The sbPA membrane did not dissolve even when immersed in water at 60 °C for 3 h. Despite a lower acid group density than the poly(p-styrenephosphonic acid) (sPA) membrane as a control sample, in which phosphonic acid groups were directly and covalently bonded to the polystyrene backbone, the sbPA membrane exhibited higher conductivities at 80 and 120 °C, especially under low humidity. For example, the sbPA membrane showed a moderate conductivity of 1.1 mS cm-1 at 120 °C and 20% relative humidity, approximately 2 orders of magnitude higher than the conductivity of the sPA membrane. The superior conductivity of the sbPA membrane could be explained by the ease of proton transport between the phosphonic acid groups even under low humidity due to the result of a high freedom of movement made possible by their connection to the polymer backbone directly through the alkylene spacer.

DOI： 10.1021/acsapm.4c02688

Next-Generation Structural Adhesives Composed of Epoxy Resins and Hydrogen-Bonded Styrenic Block Polymer-Based Thermoplastic Elastomers 査読有り Open Access

Yamada, S; Kajita, T; Nishimoto, M; Horiuchi, J; Fujii, Y; Sakaguchi, K; Hattori, K; Tamura, H; Kano, T; Sakai, T; Noro, A

ACS APPLIED MATERIALS & INTERFACES 16 巻 ( 47 ) 頁： 65270 - 65280 2024年9月

担当区分：責任著者記述言語：英語出版者・発行元：ACS Applied Materials and Interfaces

Structural adhesives are currently applied in the assembly of automobiles, aircraft, and buildings. In particular, epoxy adhesives are widely used due to their excellent mechanical strength and durability. However, cured epoxy resins are typically rigid and inflexible; thus, they have low peel and impact strength. In this study, tough cured epoxy adhesives were developed by mixing a liquid epoxy prepolymer (EP) and polystyrene-b-polyisoprene-b-polystyrene (SIS). SIS is a block polymer-based thermoplastic elastomer (TPE) composed of polystyrene (S) soluble in liquid EP and polyisoprene (I) insoluble in liquid EP, where S and I have a glass transition temperature that is higher and lower than room temperature, respectively. In addition, cured adhesives tougher than the cured adhesives containing SIS were prepared by mixing liquid EP and SIS with hydrogen-bonding groups in the I block (h-SIS). Transmission electron microscopy (TEM) observations revealed mixed S/cured EP domains, with a d-spacing of several tens of nanometers, and cured EP domains, with diameters of one hundred to several hundred nanometers, that were macroscopically dispersed in the I or hydrogen-bonded I matrix of the cured adhesive containing SIS or h-SIS. The lap shear, peel, and impact strength of cured neat EP (EP*) were 23 MPa, 45 N/25 mm, and 0.62 kN/m, respectively. Meanwhile, the cured adhesive containing 16.5 wt % SIS exhibited the slightly lower lap shear strength of 17 MPa compared to that of cured EP*, whereas the peel and impact strength of the cured adhesive with SIS were 61 N/25 mm and 7.1 kN/m, respectively, both higher than those of EP*. Furthermore, the lap shear strength of the cured adhesive containing 15.5 wt % h-SIS was 21 MPa, which was similar to that of cured EP*. The cured adhesive with h-SIS also exhibited an excellent peel strength of 97 N/25 mm and an impact strength of 14 kN/m which was 22 times higher than that of cured EP*. Therefore, mixing liquid EP and SIS improved the cured adhesive properties and flexibility of the cured epoxy adhesives compared to the cured adhesive composed of neat EP, and further enhancement of the adhesive properties was achieved by mixing liquid EP and h-SIS with hydrogen-bonding groups instead of mixing with SIS.

DOI： 10.1021/acsami.4c12540

Synthesis of a Cross-Linked Polymer Electrolyte Membrane with an Ultra-High Density of Sulfonic Acid Groups 査読有り Open Access

Sato, K; Kajita, T; Noro, A

ACS APPLIED POLYMER MATERIALS 5 巻 ( 5 ) 頁： 3480 - 3488 2023年4月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Applied Polymer Materials

Sulfonated cross-linked polystyrene membranes, one of the hydrocarbon-based polymer electrolytes membranes (PEMs), are typically synthesized via sulfonation of cross-linked polystyrene. However, it is difficult to prepare a sulfonated cross-linked polystyrene with a high sulfonation level, i.e., a high mole fraction of styrenesulfonic acid unit (fsSA), by using conventional synthetic methods. In this study, to synthesize a relatively homogeneous cross-linked poly(styrenesulfonic acid) (CL-sSA) membrane with an fsSA of 90 mol % or higher, sulfonic acid groups in a styrenesulfonate monomer were protected by esterification, and then a cross-linked polymer was synthesized using the monomer and divinylbenzene. Finally, the cross-linked polymer was converted to CL-sSA by deprotecting the alkyl groups with a base. The conductivity of the CL-sSA membrane at 80 °C and 90% RH was 0.93 S cm-1, which is extremely high and much higher than those of commercially available Nafion 212 and Selemion HSFN membranes with a low fsSA. The synthetic scheme of the CL-sSA membrane used in this study is a very effective route for preparing highly conductive cross-linked PEMs with a high fsSA

DOI： 10.1021/acsapm.3c00150

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85154545161&origin=inward

Effects of a Nanophase-Separated Structure on Mechanical Properties and Proton Conductivity of Acid-Infiltrated Block Polymer Electrolyte Membranes under Non-Humidification 査読有り Open Access

Kajita, T; Tanaka, H; Ohtsuka, Y; Orido, T; Takano, A; Iwamoto, H; Mufundirwa, A; Imai, H; Noro, A

ACS OMEGA 8 巻 ( 1 ) 頁： 1121 - 1130 2023年1月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Omega

Acid-infiltrated block polymer electrolyte membranes adopting a spherical or lamellar nanophase-separated structure were prepared by infiltrating sulfuric acid (H2SO4) into polystyrene-b-poly(4-vinylpyridine)-b-polystyrene (S-P-S) triblock copolymers to investigate the effects of its nanophase-separated structure on mechanical properties and proton conductivities under non-humidification. Lamellae-forming S-P-S/H2SO4 membranes with a continuous hard phase generally exhibited higher tensile strength than sphere-forming S-P-S/H2SO4 membranes with a discontinuous hard phase even if the same amount of Sa was infiltrated into each neat S-P-S film. Meanwhile, the conductivities of lamellae-forming S-P-S/H2SO4 membranes under non-humidification were comparable or superior to those of sphere-forming S-P-S/H2SO4 membranes, even though they were infiltrated by the same weight fraction of H2SO4. This result is attributed to the conductivities of S-P-S/H2SO4 membranes being greatly influenced by the acid/base stoichiometry associated with acid-base complex formation rather than the nanophase-separated structure adopted in the membranes. Namely, there are more free H2SO4 moieties that can release free protons contributing to the conductivity in lamellae-forming S-P-S/H2SO4 membranes than sphere-forming S-P-S/H2SO4, even when the same amount of H2SO4 was infiltrated into the S-P-S.

DOI： 10.1021/acsomega.2c06514

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85144834768&origin=inward

Development of Toughening Technology for Styrenic Thermoplastic Elastomers by Incorporating Non-Covalent Interactions 招待有り Open Access

Oda, R; Noro, A; Kajita, T; Hashimoto, S

NIHON REOROJI GAKKAISHI 51 巻 ( 5 ) 頁： 269 - 272 2023年

担当区分：筆頭著者,　責任著者記述言語：日本語出版者・発行元：Nihon Reoroji Gakkaishi

We have developed schemes for synthesizing polystyrene-b-polyisoprene-b-polystyrene (SIS) with non-covalent bonding groups via the post-polymerization chemical modification that is an industrially-friendly scheme. SIS was first reacted with maleic anhydride in a diluent, followed by reacting with alkylamine. By neutralizing the carboxy group with a metal alkoxide, ionically-modified SIS (i-SIS) was also prepared. i-SIS with a sodium cation (i-SIS(Na)) or a barium cation (i-SIS(Ba)) exhibited excellent tensile toughness of 480 and 230 MJ m–3, respectively. Drop weight impact tests also revealed that i-SIS(Ba) exhibited higher impact resistance than that of typical high-strength glass fiber-reinforced plastic. In the future, by achieving optimization of production of i-SIS in an industrial scale, i-SIS can be used for production of lightweight automobiles, resulting in contribution to achieving net-zero carbon and sustainable society.

DOI： 10.1678/rheology.51.269

Highly Impact-Resistant Block Polymer-Based Thermoplastic Elastomers with an Ionically Functionalized Rubber Phase 査読有り Open Access

Kajita, T; Noro, A; Oda, R; Hashimoto, S

ACS OMEGA 7 巻 ( 3 ) 頁： 2821 - 2830 2022年1月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Omega

There has been a great deal of interest in incorporating noncovalent bonding groups into elastomers to achieve high strength. However, the impact resistance of such elastomers has not been evaluated, even though it is a crucial mechanical property in practical usage, partly because a large-scale synthetic scheme has not been established. By ionizing the rubber component in polystyrene-b-polyisoprene-b-polystyrene (SIS), we prepared several tens of grams of SIS-based elastomers with an ionically functionalized rubber phase and a sodium cation (i-SIS(Na)) or a bulky barium cation (i-SIS(Ba)). The i-SIS(Na) and i-SIS(Ba) exhibited very high tensile toughness of 520 and 280 MJ m-3, respectively. They also exhibited excellent compressive resistance. Moreover, i-SIS(Ba) was demonstrated to have a higher impact resistance, that is, more protective of a material being covered compared to covering by typical high-strength glass fiber-reinforced plastic. As such elastomers can be produced at an industrial scale, they have great market potential as next-generation elastomeric materials.

DOI： 10.1021/acsomega.1c05609

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85122003077&origin=inward

Acidity effects of medium fluids on anhydrous proton conductivity of acid-swollen block polymer electrolyte membranes 査読有り Open Access

Kajita, T; Noro, A; Seki, T; Matsushita, Y; Nakamura, N

RSC ADVANCES 11 巻 ( 31 ) 頁： 19012 - 19020 2021年6月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：RSC Advances

Proton-conductive polymer electrolyte membranes (PEMs) were prepared by infiltrating sulfuric acid (Sa) or phosphoric acid (Pa) into a polystyrene-b-poly(4-vinylpyridine)-b-polystyrene (S-P-S) triblock copolymer. When the molar ratio of acid to pyridyl groups in S-P-S,i.e., the acid doping level (ADL), is below unity, the P-block/acid phase in the PEMs exhibited a moderately high glass transition temperature (Tg) of ∼140 °C because of consumption of acids for forming the acid-base complexes between the pyridyl groups and the acids, also resulting in almost no free protons in the PEMs; therefore, the PEMs were totally glassy and exhibited almost no anhydrous conductivity. In contrast, when ADL is larger than unity, theTgs of the phase composed of acid and P blocks were lower than room temperature, due to the excessive molar amount of acid serving as a plasticizer. Such swollen PEMs with excessive amounts of acid releasing free protons were soft and exhibited high conductivities even without humidification. In particular, an S-P-S/Sa membrane with ADL of 4.6 exhibited a very high anhydrous conductivity of 1.4 × 10−1S cm−1at 95 °C, which is comparable to that of humidified Nafion membranes. Furthermore, S-P-S/Sa membranes with lowerTgs exhibited higher conductivities than S-P-S/Pa membranes, whereas the temperature dependence of the conductivities for S-P-S/Pa is stronger than that for S-P-S/Sa, suggesting Pa with a lower acidity would not be effectively dissociated into a dihydrogen phosphate anion and a free proton in the PEMs at lower temperatures.

DOI： 10.1039/d1ra01211h

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85106893999&origin=inward

Extremely tough block polymer-based thermoplastic elastomers with strongly associated but dynamically responsive noncovalent cross-links 査読有り

Kajita, T; Tanaka, H; Noro, A; Matsushita, Y; Nozawa, A; Isobe, K; Oda, R; Hashimoto, S

POLYMER 217 巻頁： 123419 2021年3月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Polymer

To develop elastomers with excellent mechanical properties and processability, block copolymer-based thermoplastic elastomers (TPEs) with dynamic noncovalent cross-links have been actively studied in recent years. Most previous studies on such block copolymer-based TPEs have focused on incorporation of hydrogen-bonded cross-links into the block with a glass transition temperature lower than room temperature; however, the difference between the mechanical properties of hydrogen-bonded TPEs and those of other noncovalent-bonded TPEs has been hardly discussed. This work uses the polystyrene-b-polyisoprene-b-polystyrene (SIS) triblock copolymer produced in industry to synthesize hydrogen-bonded (hSIS) and ionically functionalized thermoplastic elastomers (iSIS) and compares their mechanical properties. iSIS is much tougher than hSIS; remarkably, iSIS exhibits an excellent toughness of 480 MJ m−3, because the ionic multiplets in iSIS serve as much more strongly associated but reversible cross-links. Since the elastomers can be produced at industry scale, they have great market potential for becoming next-generation elastomeric materials.

DOI： 10.1016/j.polymer.2021.123419

DOI： 10.1016/j.polymer.2021.123419

その他リンク： https://doi.org/10.1016/j.polymer.2021.123419

Self-Assembled Hybrids Composed of Block Copolymer/Porphyrin-Metal Complex via Hydrogen Bonding 査読有り

Noro A., Asai H., Higuchi K., Matsushita Y.

ACS Applied Polymer Materials 1 巻 ( 12 ) 頁： 3432 - 3442 2019年12月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Applied Polymer Materials

Macroscopically homogeneous hybrids comprising a block copolymer/porphyrin-metal complex were prepared by mixing a polystyrene-b-poly(4-vinylpyridine) (SP) block copolymer and a porphyrin metal complex with carboxyl groups. The selective and uniform incorporation of a porphyrin metal complex into the poly(4-vinylpyridine) phase of a nanophase-separated structure was achieved by hydrogen bonding between the pyridyl groups of the poly(4-vinylpyridine) block and the carboxyl groups of the porphyrin-metal complex. The phase-separated structures of the hybrids were observed by multiple structural observation tools. The morphology transition depends on the amount of the porphyrin-metal complex added. Furthermore, increasing the amount of added porphyrin-metal complex was found to lead to its precipitation. This result was attributed to a molar amount of pyridyl groups in the poly(4-vinylpyridine) block that was insufficient for hydrogen bonding compared with the amount of carboxyl groups on the porphyrin-metal complex. The precipitation of the porphyrin-metal complex was also affected by the molecular weight of the poly(4-vinylpyridine) block and was observed even when the molar ratio of pyridyl groups to carboxyl groups was larger than unity, suggesting there were still some free pyridyl groups that could be hydrogen-bonded with carboxyl groups. This result could be explained in terms of the effective concentration of the porphyrin-metal complex in solutions during solvent casting.

DOI： 10.1021/acsapm.9b00861

Acidic liquid-swollen polymer membranes exhibiting anhydrous proton conductivity higher than 100 mS cm<SUP>-1</SUP> at around 100 °C 査読有り Open Access

Kajita, T; Tanaka, H; Noro, A; Matsushita, Y; Nakamura, N

JOURNAL OF MATERIALS CHEMISTRY A 7 巻 ( 26 ) 頁： 15585 - 15592 2019年7月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Materials Chemistry A

Anhydrous proton-conductive membranes are prepared by incorporating sulfuric acid (H2SO4) into cross-linked poly(4-vinylpyridine) (CL-P), where H2SO4 mixes CL-P homogeneously at the molecular level, and therefore incorporated H2SO4 does not leach out from CL-P, even when the weight ratio of H2SO4 to CL-P is about four. The membranes are soft but self-standing and exhibit anhydrous conductivity higher than 100 mS cm-1 at around 100 °C. Furthermore, a membrane composed of polystyrene-b-poly(4-vinylpyridine)-b-polystyrene triblock copolymers and H2SO4 achieves not only high anhydrous conductivity but also good mechanical properties as a membrane.

DOI： 10.1039/c9ta01890e

DOI： 10.1039/c9ta01890e

その他リンク： https://pubs.rsc.org/en/content/articlepdf/2019/ta/c9ta01890e

Design and properties of supramolecular elastomers 招待有り査読有り

Kajita, T; Noro, A; Matsushita, Y

POLYMER 128 巻頁： 297 - 310 2017年10月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Polymer

Supramolecular elastomers are supramolecular soft polymeric materials with both transient cross-links and (semi)permanent cross-links, where transient cross-links have a finite relaxation time and are typically composed of noncovalent bonds such as hydrogen bonds, metal–ligand coordination bonds, etc., whereas (semi)permanent cross-links such as covalent bonds, crystalline segments and glassy hard domains have an infinite relaxation time. Excellent elastomeric properties were induced by a combination of all the above molecular features. However, if soft polymeric materials have only supramolecular/transient cross-links with a finite relaxation time, the materials eventually flow within a finite time and cannot behave as elastomers; in other words, they are merely supramolecular polymers that have only transient cross-links or bonds. Therefore, the key to preparing higher-performance supramolecular elastomers is their molecular design. Here, we firstly review the fundamental design of supramolecular polymers to make the differences between supramolecular polymers and supramolecular elastomers clear. Second, we discuss the simultaneous incorporation of (semi)permanent cross-links and supramolecular cross-links into polymeric materials to prepare supramolecular elastomers. Finally we summarized their properties and potential applications.

DOI： 10.1016/j.polymer.2017.03.010

Block copolymer-based supramolecular elastomers

Noro A., Kajita T., Matsushita Y.

International Polymer Science and Technology 44 巻 ( 9 ) 頁： 1 - 6 2017年9月

Enthalpy-Driven Swelling of Photonic Block Polymer Films 査読有り

Noro, A; Tomita, Y; Matsushita, Y; Thomas, EL

MACROMOLECULES 49 巻 ( 23 ) 頁： 8971 - 8979 2016年12月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Macromolecules

Nonvolatile, soft photonic films that reflect UV/vis light were prepared by enthalpy-driven swelling of lamellar-forming polystyrene-b-poly(2-vinylpyridine) (PS-P2VP) block copolymer thin films with a neat protic solvent. These films are very sensitive to further swelling with the addition of a small amount of acid. Transmission electron microscopy and ultrasmall-angle X-ray scattering of the films before and after the addition of the neat protic solvent revealed selective swelling of the P2VP phase while maintaining the lamellar morphology due to the presence of the layered glassy PS domains. P2VP is swollen due to the hydrogen bonding between a hydroxy group of a protic solvent and the pyridyl group of P2VP. The interdomain distance of the neat PS-P2VP film as measured by U-SAXS increased by about 200% and the films acted as a 1D photonic crystal reflecting UV light. Moreover, by exposing the neat PS-P2VP films to a mixture of a protic solvent and a small amount of sulfonic acid that can protonate the pyridyl groups of the P2VP block, the degree of swelling, therefore the interdomain distance and the wavelength of the reflection light, became significantly larger, resulting in color variations across the visible spectrum and suggesting that such a nonvolatile material system can be a sensor of the acid concentration in the millimolar regime for anhydrous solutions.

DOI： 10.1021/acs.macromol.6b01867

Highly Extensible Supramolecular Elastomers with Large Stress Generation Capability Originating from Multiple Hydrogen Bonds on the Long Soft Network Strands 査読有り

Hayashi, M; Noro, A; Matsushita, Y

MACROMOLECULAR RAPID COMMUNICATIONS 37 巻 ( 8 ) 頁： 678 - 684 2016年4月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Macromolecular Rapid Communications

Highly extensible supramolecular elastomers are prepared from ABA triblock-type copolymers bearing glassy end blocks and a long soft middle block with multiple hydrogen bonds. The copolymer used is polystyrene-b-[poly(butyl acrylate)-co-polyacrylamide]-b-polystyrene (S-Ba-S), which is synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Tensile tests reveal that the breaking elongation (ϵb) increases with an increase in the middle block molecular weight (Mmiddle). Especially, the largest S-Ba-S with Mmiddle of 3140k, which is synthesized via high-pressure RAFT polymerization, achieves ϵb of over 2000% with a maximum tensile stress of 3.6 MPa, while the control sample without any middle block hydrogen bonds, polystyrene-b-poly(butyl acrylate)-b-polystyrene with Mmiddle of 2780k, is merely a viscous material due to the large volume fraction of soft block. Thus, incorporation of hydrogen bonds into the large molecular weight soft middle block is found to be beneficial to prepare supramolecular elastomers attaining high extensibility and sufficiently large stress generation ability simultaneously. This outcome is probably due to concerted combination of entropic changes and internal potential energy changes originating from the dissociation of multiple hydrogen bonds by elongation.

DOI： 10.1002/marc.201500663

ブロック共重合体超分子エラストマー招待有り査読有り

野呂篤史，梶田貴都，松下裕秀

日本ゴム協会誌 90 巻 ( 1 ) 頁： 9-13 2015年12月

高分子自己組織化と分子間相互作用制御を基盤とした高性能ソフト材料の創製招待有り

野呂篤史

東海化学工業会報 287 巻頁： 5-8 2015年7月

Mechanical Property Enhancement of ABA Block Copolymer-Based Elastomers by Incorporating Transient Cross-Links into Soft Middle Block 査読有り

Hayashi, M; Matsushima, S; Noro, A; Matsushita, Y

MACROMOLECULES 48 巻 ( 2 ) 頁： 421 - 431 2015年1月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Macromolecules

We propose a new strategy to enhance mechanical properties of ABA triblock copolymer-based elastomers by incorporating transient cross-links into the soft middle block. An ABA triblock-type copolymer, poly(4-vinylpyridine)-b-[(poly(butyl acrylate)-co-polyacrylamide]-b-poly(4-vinylpyridine) (P-Ba-P), was synthesized via RAFT polymerization. In the molecular design, the poly(4-vinylpyridine) (P) end blocks with a high Tg formed pseudo-crosslink domains due to segregation against the soft Ba middle block, while acrylamide units on the middle block formed self-complementary hydrogen bonding, serving as transient crosslinks. According to tensile tests, the Young's modulus, elongation at break, maximum stress, and material toughness were 1.9 MPa, 200%, 2.6 MPa, and 2.8 MJ/m3, respectively. Comparison between mechanical properties of P-Ba-P and those of another triblock copolymer, poly(4-vinylpyridine)-b-poly(butyl acrylate)-b-poly(4-vinylpyridine) (P-B-P), revealed that P-Ba-P showed larger Young's modulus, longer elongation at break, and larger maximum tensile stress than P-B-P. Particularly, the material toughness of P-Ba-P (2.8 MJ/m3) was more than 100 times larger than that of P-B-P (0.02 MJ/m3). Rheological analysis on the basis of sticky Rouse relaxation of Ba middle block of P-Ba-P suggested that the hydrogen bonds on the middle block serve as dynamic stickers in elastic strands of elastomers under stress. Such dynamic behavior of the hydrogen bonds could prevent local concentration of applied stress for activating break/failure of the materials during elongation, leading to mechanical property enhancement of the materials. In addition, zinc chloride was blended with P-Ba-P to form metal-ligand coordination in the P end block domains, which also affected the mechanical properties of the elastomers. (Chemical Equation Presented).

DOI： 10.1021/ma502239w

Design and viscoelasticity control of supramolecular soft materials bearing noncovalent cross-links 招待有り査読有り

Noro A.

Nihon Reoroji Gakkaishi 43 巻 ( 5 ) 頁： 125 - 133 2015年

担当区分：筆頭著者,　責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Nihon Reoroji Gakkaishi

Well-controlled molecular design of supramolecular polymer gels, which can be prepared by incorporating noncovalent cross-links strategically, was proposed. In fact, supramolecular polymer gels were prepared by blending poly(2-vinylpyridine)-b-poly(ethyl acrylate)-b-poly(2-vinylpyridine) triblock copolymer (V-EA-V), poly(4-hydroxystyrene) homopolymer (H), and a nonvolatile ionic liquid (IL), where the two polymers were synthesized via reversible addition fragmentation chain transfer polymerization. The supramolecular polymer gels contained an IL as a solvent; therefore, they were called supramolecular supramacromolecular ion gels. The supramolecular ion gels represented gel-like behavior at lower temperatures whereas they flowed within a normal timescale (several seconds) at higher temperatures. Such behavior was found to be thermoreversible. Master curves prepared from frequency-dependent viscoelastic spectra on the basis of time-temperature superposition principle exhibit the plateau modulus with approximately 10 orders of magnitude in reduced frequency. It was also revealed from temperature dependency of shift factors that the longest relaxation time at a low temperature such as 50 °C was as long as 109 s. Decrement of shift factors at lower temperatures was smaller than that of shift factors at higher temperatures. This is because the origin of relaxation is formation 7 dissociation of hydrogen bonds. When the concentration of H in solution blends was varied and that of V-EA-V was kept almost the same, the temperature at G' G" (TG'=G") increased with an increase in H concentration. The sharpness of the change in G' against the temperature near TG'=G" depends on the phenol pyridine stoichiometric ratio and the number of branches of V end blocks from one H polymer. Furthermore, it was also revealed from small angle X-ray scattering measurements that supramolecular gelationlsupramolecular cross-linking was associated with formation of nanophase-separated structure. Knowledge acquired here is useful for development of novel functional soft materials and analysis interpretation of viscoelastic behavior of such materials.

DOI： 10.1678/rheology.43.125

Design and Viscoelasticity Control of Supramolecular Soft Materials Bearing Noncovalent Cross-Links

Noro, A

NIHON REOROJI GAKKAISHI 43 巻 ( 5 ) 頁： 125 - 133 2015年

イオン液体膨潤ブロック共重合体フォトニック膜のナノ構造と光学特性招待有り

冨田裕介、提嶋佳生、野呂篤史、松下裕秀

PFニュース 33 巻 ( 3 ) 頁： 9-13 2014年11月

ブロック共重合体/金属塩ハイブリッドのナノ相分離構造における構造異性体の効果招待有り

提嶋佳生、野呂篤史、松下裕秀

PFニュース 33 巻 ( 2 ) 頁： 15-19 2014年8月

Photonic Block Copolymer Films Swollen with an Ionic Liquid 査読有り

Noro, A; Tomita, Y; Shinohara, Y; Sageshima, Y; Walish, JJ; Matsushita, Y; Thomas, EL

MACROMOLECULES 47 巻 ( 12 ) 頁： 4103 - 4109 2014年6月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Macromolecules

Nonvolatile solvent swollen 1D periodic films were fabricated from lamellae-forming block copolymers with medium molecular weight by infiltrating an ionic liquid. A mixture of imidazole and imidazolium bis(trifluoromethanesulfonyl)imide as a room temperature ionic liquid was added after spin-coating of thin films of polystyrene-b-poly(2-vinylpyridine) (PS-P2VP) block copolymers having an approximately 50/50 composition to create photonic films reflecting in the visible regime. Under normal conditions of temperature and humidity, the films maintained their photonic properties for more than 100 days without perceptible change, stemming from the nonvolatility of the ionic liquid. Transmission electron microscopy revealed the selective swelling of the P2VP nanodomains by the IL and ultrasmall angle X-ray scattering measurements provided quantitative nanostructure information on the periodicities of the films. The wavelength of reflected light from photonic films was tunable by using different molecular weight block copolymers as well as by employing blends of two block copolymers. The experimental wavelength of the reflected light, detected by a fiber-optic spectrophotometer, agreed with values estimated from the Bragg condition and was able to be controlled from about 380 to 620 nm. © 2014 American Chemical Society.

DOI： 10.1021/ma500517e

Viscoelastic Properties of Supramolecular Soft Materials with Transient Polymer Network 査読有り

Hayashi, M; Noro, A; Matsushita, Y

JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS 52 巻 ( 11 ) 頁： 755 - 764 2014年6月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Polymer Science, Part B: Polymer Physics

A series of supramolecular soft materials with hydrogen bonded transient networks was prepared by blending carboxy-terminated telechelic poly(ethyl acrylate) (PEA-(COOH)2) and polyethyleneimine (PEI). Effects of PEA-(COOH)2 molecular weight (MPEA) and the blend ratio on the viscoelastic properties were investigated by rheological and small angle X-ray scattering measurements. Rubbery plateau appeared by adding PEI due to network formation with ionic hydrogen bonded crosslinks between amines on PEI and carboxylic acids on PEA-(COOH)2. The highest temperature of a storage modulus-loss modulus crossover as well as the highest flow activation energy was attained at a certain mole ratio of amines to carboxylic acids, irrelevant to MPEA, indicating optimized supramolecular networks were achieved by stoichiometric balance of two functional groups. Since telechelic PEA-(COOH)2 serves as a network strand, the plateau modulus was inversely proportional to MPEA, which was consistent with the correlation length between crosslinks estimated by X-ray scattering measurements. © 2014 Wiley Periodicals, Inc.

DOI： 10.1002/polb.23479

Structural Isomer Effects on the Morphology of Block Copolymer/Metal Salts Hybrids 査読有り

Sageshima, Y; Noro, A; Matsushita, Y

JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS 52 巻 ( 5 ) 頁： 377 - 386 2014年3月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Polymer Science, Part B: Polymer Physics

The structural isomer effects on phase behavior of block copolymer/FeCl3 hybrids were investigated by comparing structures of two series of blends based on polystyrene-b-poly(4-vinylpyridine) (PS-P4VP) and polystyrene-b-poly(2-vinylpyridine) (PS-P2VP), with the same molecular weight and the same composition. By conbining fourier transform infrared (FT-IR) spectroscopy and differencial scaninng calorimetry, successful achievements of selective dispersion of FeCl3 into poly(vinylpyridine) phase via coordination were verified. Complementary morphological observation by transmission electron microscopy and small-angle X-ray scattering (SAXS), it has been clarified that phase behavior for two isomer series is considerably different. That is, neat PS-P4VP formed thicker cylindrical domains than that of neat PS-P2VP due to much stronger Flory-Huggins interaction parameter χ, χPS-P4VP χPS-P2VP. As for PS-P2VP/FeCl3 hybrids, morphological transition can be taken place at the smaller amount of metal salt; furthermore, P2VP blend series form lamellar structures with evidently larger periodic length at the same amount of metal salt. This is probably caused by the event that excess metal salt also contributes to lamellar expansion by localizing at the center of P2VP lamellar phase. Moreover, the saturation limit of introduced metal salt in P2VP was smaller than that in P4VP due to the steric hindrance for a lone pair electrons on nitrogen atoms directed to the main chain of P2VP. These results can be explained by the structural isomer effects on the conformation of the P2VP chains at coordinated state with FeCl3, that is, P2VP chains prefer to form the intramolecular coordination due to the short range interaction so as to make themselves stiffer, whereas P4VP chains tend to adopt the long range interaction including intra- and intermolecular coordinations. © 2013 Wiley Periodicals, Inc.

DOI： 10.1002/polb.23421

Preparation and viscoelasticity of hydrogen bonded supramolecular ion gels composed of ABA triblock copolymer and C homopolymer in an ionic liquid 招待有り査読有り

Matsushima S., Hayashi M., Yamagishi H., Noro A., Matsushita Y.

Nihon Reoroji Gakkaishi 42 巻 ( 2 ) 頁： 135 - 141 2014年

担当区分：責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Nihon Reoroji Gakkaishi

Several supramolecular ion gels were prepared by mixing a poly(4-vinylpyridine)-b-poly(3, 4, 5-trimethoxystyrene)-b-poly(4-vinylpyridine) triblock copolymer (Mn = 76000) and poly(4-hydroxystyrene) (PHS, Mn = 3500) in an ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imidide, abbreviated as IL. The weight ratio of three components, i.e., triblock copolymer:PHS:IL was varied as 10:X:90 within the range of 0.16 ≤ X ≤ 3.2. Temperatureramp oscillatory shear measurements revealed that the storage modulus G′ of most of samples was larger than the loss modulus G″ at room temperature, whereas G′ < G″ at high temperatures, indicating those samples are thermoresponsive gels. G′-G″ crossover temperature reached the maximum when a molar ratio of phenol unit on PHS to pyridine unit on a triblock copolymer was nearly two. Dynamic frequency sweeps also revealed two relaxation modes with different time scales: one is associated with hydrogen bonding formation at lower frequencies and the other with friction among network strands at higher frequencies. Moreover, the sample with excesssive PHS provided a completely different relaxation mode, suggesting that incomplete network was formed between triblock copolymer and PHS © 2014 The Society of Rheology, Japan.

DOI： 10.1678/rheology.42.135

Thermoreversible Supramolecular Polymer Gels via Metal-Ligand Coordination in an Ionic Liquid 査読有り

Noro, A; Matsushima, S; He, XD; Hayashi, M; Matsushita, Y

MACROMOLECULES 46 巻 ( 20 ) 頁： 8304 - 8310 2013年10月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Macromolecules

Thermoreversible supramolecular polymer gels were prepared via metal-ligand coordination by mixing a poly(4-vinylpyridine)-b-poly(ethyl acrylate)-b-poly(4-vinylpyridine) (P4VP-PEA-P4VP) triblock copolymer and zinc chloride (ZnCl2) in a hydrophobic ionic liquid, 1-ethyl-3- methylimidazolium bis(trifluoromethylsulfonyl)imidide. FT-IR spectroscopy revealed metal-ligand coordination between zinc in ZnCl2 and pyridine groups as ligands on P4VP blocks, even in an ionic liquid. Thermoreversible viscoelastic properties between a semisolid (gel-like) state and a liquid-like state were confirmed by temperature-ramp oscillatory shear measurements. It was also revealed that thermoreversibility of supramolecular polymer gels depended strongly on stoichiometry between ligands and metals, where the maximum of storage modulus-loss modulus crossover temperature (Tgel) as an indicator of gelation was achieved when a molar amount of available coordination sites was a certain excessive amount (coordination site/ligand ratio ∼1.6). The molar ratio at the maximum Tgel is nearly independent of the number of ligands per triblock copolymer. On the other hand, the number of ligands per triblock copolymer affected the Tgel, where a larger number of ligands per triblock copolymer gave a higher Tgel, regardless of almost the same molecular weight of triblock copolymers. © 2013 American Chemical Society.

DOI： 10.1021/ma401820x

Fabrication and Modification of Ordered Nanoporous Structures from Nanophase-Separated Block Copolymer/Metal Salt Hybrids 査読有り

Sageshima, Y; Arai, S; Noro, A; Matsushita, Y

LANGMUIR 28 巻 ( 50 ) 頁： 17524 - 17529 2012年12月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Langmuir

We report facile preparation of nanoporous thin films by rinsing out a metal salt from nanophase-separated hybrid films composed of a block copolymer and a water-soluble metal salt. Nanophase-separated hybrids were prepared by mixing polystyrene-b-poly(4-vinylpyridine) (PS-P4VP) and iron(III) chloride in a solvent of pyridine, followed by solvent-casting and thermal-annealing. Film samples with a thickness of ca. 100 nm were fabricated from the nanophase-separated hybrids by using a microtoming technique. Metal salts in the films were removed by immersion into water to fabricate nanopores. Morphological observations were conducted by using transmission electron microscopy (TEM). Ordered cylindrical nanopores were clearly observed in the thin films prepared from the water-immersed hybrids which originally present cylindrical nanodomains. These nanoporous films were modified by loading another metal salt, samarium(III) nitrate, into the nanopores on the basis of the coordination ability of P4VP tethered to the pore walls. The samples after loading treatment were evaluated by TEM observation and elemental analysis with energy dispersive X-ray spectroscopy. © 2012 American Chemical Society.

DOI： 10.1021/la3042023

Preparation and Morphology of Hybrids Composed of a Block Copolymer and Semiconductor Nanoparticles via Hydrogen Bonding 査読有り

Noro, A; Higuchi, K; Sageshima, Y; Matsushita, Y

MACROMOLECULES 45 巻 ( 19 ) 頁： 8013 - 8020 2012年10月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Macromolecules

We report a systematic study on preparation and morphological observation of hybrids composed of a block copolymer and hydroxy-capped semiconductor nanoparticles via hydrogen bonding. Three polystyrene-b-poly(4-vinylpyridine) (PS-P4VP) block copolymers with exactly the same PS chain length but with different P4VP chain length were synthesized via reversible addition- fragmentation chain transfer polymerization. To prepare hybrids, each PS-P4VP was mixed with hydroxy-capped nanoparticles made of cadmium selenide (h-CdSe), by varying a weight ratio of PS-P4VP:h-CdSe. Morphology of three series of hybrids was observed by both transmission electron microscopy and small-angle X-ray scattering. Hybrids composed of h-CdSe and PS-P4VP bearing a long P4VP block represents uniform morphology of a single nanophase-separated structure, where domain spacing expansion and morphology transition induced by addition of h-CdSe were observed. On the other hand, nonuniform morphology, i.e., macrophase separation accompanied by overflow of h-CdSe from nanophase-separated domains, was observed in hybrids containing PS-P4VP bearing a short P4VP block. These results are attributed to hydrogen-bonding formation and the stoichiometric balance of functional groups. © 2012 American Chemical Society.

DOI： 10.1021/ma301665e

Creation and control of new morphologies via supramacromolecular self-assembly 招待有り査読有り Open Access

Matsushita, Y; Noro, A; Takano, A

POLYMER JOURNAL 44 巻 ( 1 ) 頁： 72 - 82 2012年1月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Polymer Journal

Various supramacromolecular self-assembly mechanisms of complex polymer systems via non-covalent bonding interactions were summarized in this article. Basically, three types of systems were introduced. The first class is the morphological transition of block copolymer/homopolymer blends with hydrogen bonds (HBs) or block copolymer/metal salt hybrids via complex formation. Systematic morphological transition was observed upon the addition of a homopolymer or metal salt, depending on its composition of volume fraction. The second class consists of the formation of block copolymer-type supramacromolecules via hydrogen bonding between two chemical moieties connected at one end of each polymer chain, resulting in new nanophase-separated structures. As an advanced branch of this second class, new morphologies were observed in block copolymer/block copolymer blends with HBs. The third class is supramacromolecular gelation, which was observed for ABA triblock copolymer/C homopolymer or telechelic polymer/homopolymer blends, both including complementary electron donors/acceptors. © The Society of Polymer Science, Japan (SPSJ) All rights reserved.

DOI： 10.1038/pj.2011.81

Design and properties of supramolecular polymer gels 招待有り査読有り

Noro, A; Hayashi, M; Matsushita, Y

SOFT MATTER 8 巻 ( 24 ) 頁： 6416 - 6429 2012年

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Soft Matter

Supramolecular polymer gels are precisely designed physical gels brought together by reversible secondary interactions to form three dimensional networks of melt macromolecules. Generally, they differ from supramolecular gels because they are comprised of polymers instead of low molecular weight compounds. Recently, much effort has focused on designing supramolecular polymer gels and related materials with excellent properties; indeed, improvements have been made in their supramolecular interactions, complementarity in the non-covalent bonding units, the nature of the macromolecular building blocks, and strand elasticity of supramolecular polymer networks. Owing to the precise molecular design, they represent nanophase separation and characteristic viscoelasticity. Here, we review supramolecular polymer gels in terms of molecular design, morphology, and rheology. We also discuss future directions in practical application of supramolecular polymer gels. © 2012 The Royal Society of Chemistry.

DOI： 10.1039/c2sm25144b

Nanophase-Separated Supramolecular Assemblies of Two Functionalized Polymers via Acid-Base Complexation 査読有り

Noro, A; Ishihara, K; Matsushita, Y

MACROMOLECULES 44 巻 ( 16 ) 頁： 6241 - 6244 2011年8月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Macromolecules

Preparation of block supramacromolecules usually requires precise synthesis of end-modified polymers as building blocks. Moreover, the efficiency of the formation of block supramacromolecules from the blends of end-modified polymers is strongly influenced by stoichiometry between noncovalent bonding groups on each end-modified polymer. To understand the morphological behavior of the blends at the nanoscopic scale, small-angle X-ray scattering (SAXS) measurements were conducted at room temperature at the beamline 15 A in the Photon Factory, Tsukuba, Japan. According to the theory by Semenov, the morphology formation of disklike multiplets and lamellae is more favored than spherical multiplets at so-called superstrong segregation limit between a charged component and an uncharged component, regardless of the very small fraction of a charged component.

DOI： 10.1021/ma201440v

Simple preparation of supramolecular polymer gels <i>via</i> hydrogen bonding by blending two liquid polymers 査読有り

Noro, A; Hayashi, M; Ohshika, A; Matsushita, Y

SOFT MATTER 7 巻 ( 5 ) 頁： 1667 - 1670 2011年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Soft Matter

Preparation of supramolecular polymer gels based on simple molecular design was demonstrated by blending carboxyl-terminated telechelic polymers and poly(ethyleneimine), where balance of an attractive force due to hydrogen bonding and a repulsive force induced by phase separation between polymers has been found as a key factor of supramolecular gelation. © 2011 The Royal Society of Chemistry.

DOI： 10.1039/c0sm01334j

水素結合性超分子ゲルの調製とその粘弾性挙動招待有り

野呂篤史

ケミカルエンジニヤリング 55 巻 ( 9 ) 頁： 675-679 2010年9月

Preparation and Morphology Control of Block Copolymer/Metal Salt Hybrids via Solvent-Casting by Using a Solvent with Coordination Ability 査読有り

Noro, A; Sageshima, Y; Arai, S; Matsushita, Y

MACROMOLECULES 43 巻 ( 12 ) 頁： 5358 - 5364 2010年6月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Macromolecules

We report a systematic study on preparation and morphology control of macroscopically homogeneous hybrid films composed of a block copolymer and a metal salt, where one block interacts with a metal salt by metal-to-ligand coordination. Hybrids were prepared by blending a polystyrene-b-poly(4- vinylpyridine) (PS - P4VP, Mn=37K, φs=0.79) block copolymer and iron(III) chloride (FeCl3) with changing the mole fraction of FeCl3. To prevent the rapid cross-linking formation between P4VP and FeCl3, pyridine as a polar solvent with the coordination ability was used at the solvent-casting stage, which turned out to be effective to prepare macroscopically homogeneous films with a large amount of FeCl3. Transmission electron microscopy and small-angle X-ray scattering measurements were carried out to observe the morphology of thermally annealed samples at the nanoscopic scale. It was revealed that simple two-phase nanostructures were observed due to homogeneously mixing of FeCl3 into a P4VP phase up to 0.9 mol equiv of FeCl3 to pyridine units in P4VP. This indicates FeCl3 works as a filler in a P4VP phase just as small homopolymers: domain expansion and morphology transition were observed as the amount of added FeCl3 increases. However, overflow of FeCl 3 was observed in the hybrid with an amount of 1.0 mol equiv of FeCl3. This is probably due to the saturation of incorporated FeCl3, indicating that morphology of the present system can be controlled by stoichiometric balance between 4-vinylpyridine units and FeCl 3. © 2010 American Chemical Society.

DOI： 10.1021/ma1007286

Thermoreversible Morphology Transition from Block-Type Supramacromolecules via Hydrogen Bonding in an Ionic Liquid 査読有り

Noro, A; Yamagishi, H; Matsushita, Y

MACROMOLECULES 42 巻 ( 17 ) 頁： 6335 - 6338 2009年9月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Macromolecules

Thermoreversible morphology transition from block-type supramacromolecules via hydrogen bonding was analyzed in an ionic liquid. Two macromolecular building blocks were designed to form a block-type supramacromolecule: one is a poly(3,4,5-trimethoxystyrene) with a small linker of poly(4-hydroxystyrene) on the end as a hydrogen-bonding proton donor, and the other is a poly(n-butyl acrylate) with a small linker of poly-(2-vinylpyridine) on the end as a hydrogen-bonding proton acceptor, both of which are soluble or at least dispersible in the ionic liquid. Measurements were taken every 20°C from lower to higher temperatures and vice versa. SAXS was used to reveal the thermo-reversible morphological transition from block-type supramacromolecules in an ionic liquid induced by hydrogen-bonding association-dissociation. The results show that this type of thermoreversible morphology transition in nanometer length scale could be achieved in similar systems if proper molecular design is performed.

DOI： 10.1021/ma901143k

複合高分子の階層的秩序構造 : 異種分子鎖の結合性に注目して招待有り査読有り

松下裕秀、林田研一、高野敦志、野呂篤史

日本ゴム協會誌 82 巻 ( 9 ) 頁： 405-410 2009年9月

Thermoreversible Morphology Transition from Block-Tyoe Supramacromolecules via Hydrogen Bonding in an Ionic Liquid 査読有り

Noro, Atsushi; Yamagishi, Hajime; Matsushita, Yushu

Macromolecules 42 巻 ( 17 ) 頁： 6335-6338 2009年9月

Gelation Mechanism of Thermoreversible Supramacromolecular Ion Gels via Hydrogen Bonding 査読有り国際共著

Noro, A; Matsushita, Y; Lodge, TP

MACROMOLECULES 42 巻 ( 15 ) 頁： 5802 - 5810 2009年8月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Macromolecules

A series of supramacromolecular ion gels were prepared from blends of a poly(2-vinylpyridine)-b-poly(ethyl acrylate)-b-poly(2-vinylpyridine) (VEAV) triblock copolymer and a poly(4-hydroxystyrene) (H) homopolymer in an ionic liquid. The VEAV concentration was held at 10 wt %, and the H concentration was varied from 0 to 8 wt %. The solvent was the room temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (EMITFSI). Above 160°C all samples formed homogeneous solutions, but upon cooling gels were formed due to increased hydrogen bonds between the V blocks and H cross-linkers. The gelation mechanism was investigated in detail by rheology and small-angle X-ray scattering. The gel point (gel-liquid transition temperature) increased with the concentration of the cross-linkers. The dynamic moduli, G′ and G″, showed excellent time-temperature superposition, and gave master curves extending over 15 orders of magnitude in reduced frequency. The shift factors aT showed the same strong temperature dependence for all the samples, which is attributed to the increasing number of hydrogen bonds between a given V block and H cross-linker upon cooling below the gel point. The gel quality was assessed in terms of the modulus value, Gx, the sharpness of the change in dynamic moduli with temperature near the gel point, and the minimum value of tan δ in the gel regime. By all three measures the best gel was formed at the mole ratio closest to 1:1 of pyridine:phenol units, i.e., stoichiometric balance. Furthermore, the maximum value of Gx corresponded to 50% of the EA blocks being elastically effective, consistent with expectation given the tendency for midblocks to loop back into the same micelle. A gel-like response was also obtained upon mixing 10% of a poly(2-vinylpyridine)-b-poly(ethyl acrylate) (VEA) diblock copolymer and H homopolymers in EMITFSI. However, in this case the rheological properties resulted from congestion of micelles rather than bridging chains. Small angle X-ray scattering revealed the presence of a nanophase-separated state, but without any significant change on traversing the gel point, or between diblock and triblock samples. © 2009 American Chemical Society.

DOI： 10.1021/ma900820g

Hierarchical nanophase-separated structures created by precisely-designed polymers with complexity 招待有り査読有り Open Access

Matsushita, Y; Takano, A; Hayashida, K; Asari, T; Noro, A

POLYMER 50 巻 ( 10 ) 頁： 2191 - 2203 2009年5月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Polymer

This review paper summarizes recent advances in self-assembly of complex polymers, focusing on three characteristic polymeric systems. The first is star-branched polymers of the ABC type, the second one consists of multiblock terpolymers with different chain lengths, while the third comprises supramacromolecular assembly systems with hydrogen and ionic bonding interactions between different polymer species. A quasicrystalline tiling structure with mesoscopic length scale has been found for the first star polymer system as well as the periodic Archimedean tiling structures, and moreover three-dimensional Zincblende network structure has been discovered. Furthermore the hierarchical structures having two length scales have been also found for the ABC star molecules whose chain length ratios, that is, A/B and/or A/C are larger than approximately five. Hierarchical structures with double periodicity have been observed for the hexablock and undecablock terpolymers and it has been revealed that their morphology changes systematically depending on composition of polymeric species. Poly(4-hydroxystyrene) (H) homopolymer was found to be dissolved into microdomain of poly(2-vinylpyridine) formed by poly(styrene-b-2-vinylpyridine) due to hydrogen bonding interaction, resulting in the origin of morphological transitions depending on the composition of H homopolymer added. Hierarchical structures possessing double periodicity have been found for poly(isoprene-b-2-vinylpyridine)/poly(styrene-b-4-hydroxystyrene) blends depending on both volume fractions of component polymers and blend ratio. Blends of different homopolymers with several complementary nucleotides or acid/base moieties on chain ends have been confirmed to show nanophase-separated structures as a result of successful formation of "supramacromolecules". © 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2009.02.047

Stoichiometric Effects on Nanostructures of Block- and Graft-Type Supramacromolecules via Acid-Base Complexation 査読有り

Noro, A; Tamura, A; Wakao, S; Takano, A; Matsushita, Y

MACROMOLECULES 41 巻 ( 23 ) 頁： 9277 - 9283 2008年12月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Macromolecules

We report a systematic study on nanophase-separated structures from block- and graft-type supramacromolecules via acid-base complexation, where supramacromolecules are termed as supramolecules composed of a pair of macromolecules with complementary noncovalent bonding moieties. Block- or graft-type supramacromolecules were built up by blending component polymers, that is, sulfonic acid-terminated polystyrene (PS-SO3H, Mn = 19 k) or polystyrene-block-poly(4-styrenesulfonic acid) (PS-P(SSO 3H), Mn =23k) with primary amine-terminated polyisoprene (PI-NH 2, Mn = 17 k). Self-assembled nanostructures of the blends were confirmed complementarity by transmission electron microscopy and small-angle X-ray scattering. At larger acid/base molar ratio, the blends show comparatively ordered nanophase-separated structures without macrophase-separated large PS domain. Morphological transition controlled by composition has occurred in the blends of PS-P(SSO3H)/PINH2 as ordinary block copolymers show, though the blends of PS-SO3H/PI-NH2 showed macrophase separation at excess ratio of PI-NH2 to PS-SO 3H. The difference in composition dependence of morphology between two blend series is resulted from stoichiometric effects of sulfonic acid vs amine. Therefore, PS-P(SSO3H) is more useful to build up various supramacromolecular complexes with PI-NH2 than PS-SO3H just by changing the molar ratios of component polymers, that is, multiple noncovalent bonding can be found more advantageous, resulting in conforming graft-type supramacromolecules, not a block-type supramacromolecule from. PI-NH2 and PS-SO3H. © 2008 American Chemical Society.

DOI： 10.1021/ma801661c

Thermoreversible supramacromolecular ion gels via hydrogen bonding 査読有り国際共著

Noro, A; Matsushita, Y; Lodge, TP

MACROMOLECULES 41 巻 ( 15 ) 頁： 5839 - 5844 2008年8月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Macromolecules

We report the thermoreversible viscoelastic properties of a supramolecular ion gel. Two building blocks were used to form "supramacromolecules". An ABA triblock copolymer (Mn = 50 000, poly(2-vinylpyridine)-b- poly(ethyl acrylate)-b-poly(2-vinylpyridine)) (P2VP-PEA-P2VP), with a mole ratio of 0.1/0.8/0.1 as a telechelic polymer, and a poly(4-hydroxystyrene) (PHS) homopolymer, with Mn = 6600 as a connector, form a physical gel via hydrogen bonding between P2VP and PHS. The thermally stable, hydrophobic ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMITFSI) provided a good solvent medium for PEA from room temperature up to at least 160°C. A solution containing 10 wt % P2VP-PEA-P2VP and 4% PHS was a liquid at elevated temperatures but on cooling formed a network at 141.5°C. Dynamic shear moduli obtained as a function of frequency at various temperatures from 30 to 160°C could be superposed to form excellent master curves, with a distinct plateau modulus extending over more than 11 orders of magnitude in frequency. The longest relaxation time inferred from the time-temperature superposition shift factors showed a similar 11 order of magnitude increase on cooling. This remarkable temperature sensitivity of the supramacromolecular ion gel is attributed to the formation of multiple hydrogen bonds between a given P2VP block and PHS cross-linker. A hydrogen bond energy of 13 kJ/mol was estimated from temperature-dependent FTIR measurements, and a straightforward analysis yielded an estimate of the number of hydrogen bonds per P2VP block as a function of temperature. This system is distinct from other supramolecular hydrogen-bonded polymers, and from hydrophobically modified associating polymers, in that below the gelation temperature the number of physical cross-links is independent of temperature, but the strength of each association, namely, the number of active hydrogen bonds within a particular cross-link site, increases strongly on cooling. © 2008 American Chemical Society.

DOI： 10.1021/ma800739c

Composition-dependent morphological transition of hierarchically-ordered structures formed by multiblock terpolymers 査読有り

Masuda, J; Takano, A; Suzuki, J; Nagata, Y; Noro, A; Hayashida, K; Matsushita, Y

MACROMOLECULES 40 巻 ( 11 ) 頁： 4023 - 4027 2007年5月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Macromolecules

Morphological transition of two types of multiblock terpolymers with composition has been investigated. One is undecablock terpolymers of the PISISISISIP type, while the other is hexablock terpolymers of the PISISI type, where P, I, and S denote poly(2-vinylpyridine), polyisoprene, and polystyrene, respectively. These polymer samples were prepared on the basis of anionjc polymerization method. The volume fractions of P, φp, of the former are 0.08, 0.21, 0.53, whereas those of the latter are 0.64, 0.75, and 0.87. Nanophase-separated structures were observed by TEM and SAXS, and it was confirmed that their hierarchical morphology transforms from spheres-in-lamellae structure into cylinders-in-lamellae, lamellae-in-lamella, and coaxial cylinderical structures and finally into onionlike spherical structure with increasing volume fraction of the P component. From these results, it has been found that morphological transition of multiblock terpolymers takes place obeying conventional rule, i.e., the domain shape of P component varies as sphere-cylinder-lamella-matrix as φp increases with keeping hierarchical lamellar structure from I and S. © 2007 American Chemical Society.

DOI： 10.1021/ma070155s

中性子反射率法による埋もれた高分子界面の構造評価招待有り査読有り

鳥飼直也、野呂篤史、松下裕秀

放射線化学 83 巻頁： 29-35 2007年3月

Neutron reflectometry on interfacial structures of the thin films of polymer and lipid 招待有り査読有り Open Access

Torikai, N; Yamada, NL; Noro, A; Harada, M; Kawaguchi, D; Takano, A; Matsushita, Y

POLYMER JOURNAL 39 巻 ( 12 ) 頁： 1238 - 1246 2007年

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Polymer Journal

Neutron reflectometry is a very powerful and essential technique for the studies on material interfaces due lo its high spatial resolution, ∼a few tenths of nm, along the depth direction. The use of neutron as a probe is a big advantage for structural analysis on soft-materials, since the scattering contrast can be highly enhanced in hydrogenous materials such as polymers, surfactants, lipids, proteins, etc.. without big changes in their physical and chemical properties by substituting all or part of the hydrogen atoms in the molecules with deuterium (a deuterium labeling method). Furthermore, the neutron reflectometry can explore deeply-buried interfaces such as solid/liquid interfaces in a non-destruetive way, and make in situ measurements combined with various sample environments due to its high transmission to the materials. In this article, the neutron reflectometry is reviewed from the standpoint of researches on interfacial structures of the thin films of polymer and lipid, and its future prospects at a high-intensity pulsed-neutron source are presented. © 2007 The Society of Polymer Science.

DOI： 10.1295/polymj.PJ2007113

Effect of chain length and blend ratio of building blocks on nanophase-separated structures from block-type supramacromolecules via ionic interaction

Noro A., Arai S., Takano A., Matsushita Y.

Polymer Preprints, Japan 55 巻 ( 2 ) 頁： 5332 - 5333 2006年12月

担当区分：筆頭著者,　責任著者出版者・発行元：Polymer Preprints, Japan

The effect of weight fraction of building blocks on nanophase-separated structures from block-type supramacromolecules via ionic interaction was investigated. Two different end-terminated homopolymers, polystyrene terminated with sulfonic acid and polyisoprene terminated with primary amine, were prepared by using living anionic polymerizations. These two polymers were blended variously in terms of weight fraction. All blends used in this study were confirmed to show nanophase-separated structures by transmission electron microscopy and small-angle X-ray scattering, which indicates the formation of block-type supramacromolecules via ionic interaction in all blends. It has been found that simple nano-structure is formed when the polymer terminated with sulfonic acid is rich, whereas multiple nano-structures are formed when the polymer terminated with primary amine is rich.

Neutron reflection studies on lamellar microphase-separated structures of two-component block copolymers with composition distribution 査読有り

Torikai, N; Noro, A; Okuda, M; Odamaki, F; Kawaguchi, D; Takano, A; Matsushita, Y

PHYSICA B-CONDENSED MATTER 385 巻頁： 709 - 712 2006年11月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Physica B: Condensed Matter

Segmental distribution of polystyrene blocks in lamellar microphase-separated poly(styrene-block-2-vinylpyridine) (SP) with wide composition distribution was investigated by neutron reflectivity measurements using deuterium-labeled polymers. Block copolymers with wide composition distribution were produced by mixing three monodispersed parent block copolymers, which were synthesized by an anionic polymerization method to have the same total molecular weight but with different volume fractions. The block copolymer blends whose overall S/P ratio is 0.5/0.5 were found to form a uniform lamellar structure, where lamellae were highly oriented along the direction parallel to the film surface and the interfacial thickness was evaluated as 40 Å. It was clarified that a shorter block chain in the microdomain is localized at the domain boundary, while a longer one has a peak at the center of microdomain in its segmental distribution profile. © 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.05.303

Chain localization and interfacial thickness in microphase-separated structures of block copolymers with variable composition distributions 査読有り

Noro, A; Okuda, M; Odamaki, F; Kawaguchi, D; Torikai, N; Takano, A; Matsushita, Y

MACROMOLECULES 39 巻 ( 22 ) 頁： 7654 - 7661 2006年10月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Macromolecules

The effect of composition distribution on microphase-separated structures of AB diblock and BAB triblock copolymers was investigated at the molecular level by measurements of neutron reflectivity. Monodispersed three poly(styrene)-d 8-block-poly(2-vinylpyridine) (DP) and three labeled triblock copolymers (PDP) and unlabeled counterparts were synthesized by a living anionic polymerization process designed to yield constant molecular weight with different volume fractions. The selective labeling method employs the blending of copolymers for a segmental distribution study while the labeled polymers are mixed for an interfacial study. Scattering length density profiles were observed by neutron reflectivity measurements for blended thin films produced by spin-coating and successive thermal annealing. It was confirmed that the blended thin films exhibit simple alternating lamellar structures, an observation consistent with the observed structures of bulk specimens. The localization phenomenon of longer and shorter block chains was also investigated. Longer block chains are generally localized at the center of the domains while the shorter block chains are localized near the domain interface as suggested by previous morphological observations. Interfacial thickness increases with an increase in composition distribution index for both diblock and triblock systems. The incremental increase for the triblock system is larger than that of the diblock system. © 2006 American Chemical Society.

DOI： 10.1021/ma061487k

Preparation of a block-type supramacromolecule composed of two polymers terminated with oligonucleotides

Noro A., Nagata Y., Aral S., Takano A., Matsushita Y.

Polymer Preprints, Japan 55 巻 ( 1 ) 2006年10月

担当区分：筆頭著者,　責任著者出版者・発行元：Polymer Preprints, Japan

Control of nanostructure formation from a diblock-type supramacromolecule via biocomplementary hydrogen bonding has been achieved. Two polymers used in this study are poly(4-trimethylsilylstyrene) abbreviated as PTMSS and poly(styrene-d8) as PSd8. Three complementary nucleotides were introduced into these polymers on their ends, that is, three thymidine phosphates for PTMSS and three 2'-deoxyadenosine phosphates for PSd8, using the previously developed phosphoramidite method. Association behavior in a solution was examined with NMR, and a cast bulk film obtained from a solution was confirmed to show nanophase-separated structure by TEM and SAXS. Suppression of this nanostructure formation was also attained by adding a smaller-size agent as an inhibitor.

Nanophase-separated synchronizing structure with parallel double periodicity from an undecablock terpolymer 査読有り

Masuda, J; Takano, A; Nagata, Y; Noro, A; Matsushita, Y

PHYSICAL REVIEW LETTERS 97 巻 ( 9 ) 2006年9月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Physical Review Letters

A new nanophase-separated structure with parallel double periodicity has been identified for an undecablock terpolymer in bulk. The polymer includes two long poly(2-vinypyridine) (P) chains on each end, with five short polyisoprene (I) and four short polystyrene (S) chains at the center. This polymer exhibits a hierarchical lamellar structure with two crystallographic periods: 88 nm and 16 nm. The 88 nm period includes one thick P lamella and five thin I-S-I-S-I lamellae, of extremely high orientation. © 2006 The American Physical Society.

DOI： 10.1103/PhysRevLett.97.098301

Diblock-type supramacromolecule via biocomplementary hydrogen bonding 査読有り

Noro, A; Nagata, Y; Takano, A; Matsushita, Y

BIOMACROMOLECULES 7 巻 ( 6 ) 頁： 1696 - 1699 2006年6月

担当区分：筆頭著者,　責任著者記述言語：英語出版者・発行元：Biomacromolecules

Control of nanostructure formation by a diblock-type supramacromolecule via biocomplementary hydrogen bonding has been achieved. Two different homopolymers, poly(4-trimethylsilylstyrene) and poly(styrene-d8), that are end-decorated with complementary oligonucleotides, i.e., thymidine phosphates and deoxyadenosine phosphates, were prepared by using the phosphoramidite method and blended successively. Association behavior in a blend solution was examined with NMR, and a cast bulk film obtained from the solution has been confirmed to show a nanophase-separated structure by transmission electron microscopy and X-ray scattering. Suppression of this nanostructure formation of a block-type supramacromolecule was also attained by adding a smaller agent as an inhibitor. © 2006 American Chemical Society.

DOI： 10.1021/bm0602280

Molecular design of block- and graft polymers and their nanophase-separated hierarchical structures in condensed systems 招待有り査読有り

Matsushita Y., Takano A., Torikai N., Noro A.

Kobunshi Ronbunshu 63 巻 ( 4 ) 頁： 205 - 218 2006年4月

担当区分：最終著者記述言語：日本語出版者・発行元：Kobunshi Ronbunshu

Studies on self-assembled multiphase structures of block- and graft polymers in condensed systems were reviewed. The article includes six chapters. Individual chapters are as follows: Chap. 1, Introduction; Chap. 2; history of nanophase-separated structure; Chap. 3, preparation and characterization of polymer samples; Chap. 4, morphological observations; Chap. 5; several properties; and Chap. 6, summary. The main chapter is Chap. 4. It consists of 1) morphological transition with composition, 2) domain spacing and chain dimensions of component polymers in bulk, 3) phase transition depending on external fields and microdomain interface, and 4) new hierarchical structures from newly-designed polymers. Basically amorphous polymers were treated either in glassy state or in rubbery state to avoid confusion. Amphiphilic molecules or polyelectrolytes in solutions and micelle formation of block copolymers in selective solvents were excluded due to lack of space though such fields have potential importance. Two schemes and 16 figures were used to explain research achievements and about 100 references were cited.

DOI： 10.1295/koron.63.205

Preparation and characterization of a styrene-isoprene undecablock copolymer and its hierarchical microdomain structure in bulk 査読有り

Nagata, Y.; Masuda, J.; Noro, A.; Cho, D. Y.; Takano, A.; Matsushita, Y.

Macromolecules 38 巻頁： 10220-10225 2005年11月

A mesoscopic Archimedean tiling having a new complexity in an ABC star polymer 査読有り

Takano, A.; Kawashima, W.; Noro, A.; Isono, Y.; Tanaka, N.; Dotera, T.; Matsushita, Y.

JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS 43 巻頁： 2427-2432 2005年9月

Novel synthesis and characterization of bioconjugate block copolymers having oligonucleotides 査読有り

Noro, A.; Nagata, Y.; Tsukamoto, M.; Hayakawa, Y.; Takano, A.; Matsushita, Y.

Biomacromolecules 6 巻頁： 2328-2333 2005年7月

Effect of molecular weight distribution on microphase-separated structures from block copolymers 査読有り

Noro, A.; Cho, D.; Takano, A.; Matsushita, Y.

Macromolecules 38 巻頁： 4371-4376 2005年5月

TGIC separation of PS-b-P2VP diblock and P2VP-b-PS-b-P2VP triblock copolymers according to chemical composition 査読有り

Cho, D.H..; Noro, A.; Takano, A.; Matsushita, Y.

Macromoleules 38 巻頁： 3033-3036 2005年4月

Effect of composition distribution on microphase-separated structure from BAB triblock copolymers 査読有り

Noro, A.; Iinuma, M.; Suzuki, J.; Takano, A.; Matsushita, Y.

Macromolecules 37 巻頁： 3804-3808 2004年5月

Effect of Composition Distribution on Microphase-Separated Structure from Diblock Copolymers 査読有り

Y. Matsushita, A. Noro, M. Iinuma, J. Suzuki, H. Ohtani, A. Takano

Macromolecules 36 巻頁： 8074-8077 2003年

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