担当区分：最終著者,　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  

The polymerization of solvophobic monomers from both ends of solvophilic polymers produces BAB triblock copolymers in solution. The self-assembly of the extending solvophobic blocks may lead to network formation and gelation. This process, referred to as polymerization-induced self-assembly (PISA) in triblock copolymers, is a topic of significant interest. The underlying mechanism, however, has been poorly understood in comparison to that of PISA in diblock copolymers. In this study, we used two independent in situ time-resolved techniques─small-angle X-ray scattering and oscillatory rheology─to monitor the PISA and gelation process of triblock copolymers for the first time. We discovered that the gelation proceeds instantaneously after an induction period and is distinct from conventional gelation processes that involve the polycondensation or cross-linking reactions of polymers. This study sheds light on the entire process of PISA and network formation during the synthesis of triblock copolymers.

DOI： 10.1021/acs.macromol.3c00444

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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  

In this study, the unique tensile properties of acrylate elastomers prepared using macro cross-linker polymers with multiple vinyl side groups are analyzed. For the preparation of the macro cross-linker, poly(ethyl acrylate) copolymers bearing hydroxy functional groups are synthesized, followed by the hydroxy-isocyanate reaction with 2-isocyanatoethyl acrylate. Subsequently, the elastomers samples are prepared by UV polymerization of ethyl acrylate in the presence of the macro cross-linkers. The tensile properties of the elastomers in the small elongation region are similar to those of typical elastomers prepared using divinyl cross-linkers, whereas the stress upturn in the large elongation region is considerably different. The stress upturn varies based on the fraction of vinyl side groups in the macro cross-linkers, whereas stress in the small elongation region remains unchanged. These properties are analyzed using various theoretical models. The results reveal that there is artificial inhomogeneity in the cross-link density for samples prepared by the macro cross-linkers, where the short poly(ethyl acrylate) strands inside the macro cross-linker limit the overall chain stretchability. On the whole, this study demonstrates a new method for tuning elastomer properties, especially at large deformation.

DOI： 10.1002/marc.202200936

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Polymers  

An amphiphilic diblock copolymer (PChM-PNIPAM), composed of poly(cholesteryl 6-methacryloyloxy hexanoate) (PChM) and poly(N-isopropyl acrylamide) (PNIPAM) blocks, was prepared via reversible addition–fragmentation chain transfer radical polymerization. The PChM and PNIPAM blocks exhibited liquid crystalline behavior and a lower critical solution temperature (LCST), respectively. PChM-PNIPAM formed water-soluble polymer micelles in water below the LCST because of hydrophobic interactions of the PChM blocks. The PChM and PNIPAM blocks formed the core and hydrophilic shell of the micelles, respectively. With increasing temperature, the molecular motion of the pendant cholesteryl groups increased, and a liquid crystalline phase transition occurred from an amorphous state in the core. With further increases in temperature, the PNIPAM block in the shell exhibited the LCST and dehydrated. Hydrophobic interactions of the PNIPAM shells resulted in inter-micellar aggregation above the LCST.

DOI： 10.3390/polym15030770

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Chemistry Letters  

Polyion complex (PIC) micelles having a hydrodynamic radius of approximately 20 nm were prepared in water by simply mixing a pair of double hydrophilic oppositely charged diblock copolymers composed of a first block containing pendant phosphobetaine groups and a second cationic or anionic styrenebased polyelectrolyte block. The PIC micelles were stable under high salt concentration because the formation of the PIC micelles was driven by both electrostatic and hydrophobic interactions.

DOI： 10.1246/cl.220241

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担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.macromol.2c00485

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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  

Polymer vesicles (polymersomes) have received considerable attention in the last several decades, but little has been known about the kinetics of the formation process, despite their importance both scientifically and in practical applications. Here, we reported the formation kinetics of polymer vesicles in aqueous NaCl solutions of anionic-neutral and cationic-neutral block copolymers when they transform from micelles with a polyelectrolyte complex core. Vesicle formation from spherical or cylindrical micelles was initiated by fast mixing with a stopped-flow device. We then employed time-resolved ultrasmall-angle X-ray scattering with millisecond resolution, which enabled monitoring the kinetic process of vesicle formation. An in-depth analysis of the scattering data elucidated the following processes: in the case that the initial state was spherical micelles, they grew with time to form short cylindrical micelles. These short cylindrical micelles then transformed into disklike micelles, which subsequently closed to form vesicles. On the other hand, when the initial state involved cylindrical micelles, the disklike micelles similarly assembled, which then transformed into vesicles. The bilayer membrane of vesicles used in this study was 4 times thicker than that of vesicles formed from conventional low-molecular-weight surfactants; hence, the bending rigidity of the bilayer was approximately 16 times higher. Due to this feature, the kinetic process was different from that of conventional low-molecular-weight surfactants, in particular, an increase in the size of the disklike micelles was not observed. Instead, the weight fraction of the disklike micelles gradually decreased, and concomitantly, the weight fraction of vesicles increased since the larger transient disklike micelles or bowl-like micelles were unstable. This behavior could be well reproduced by our proposed kinetic model. This is the first report on the self-assembly kinetics of polymer vesicles probed by time-resolved small-angle scattering.

DOI： 10.1021/acs.macromol.1c02210

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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 have investigated the colloidal phase-separating dilute solution of aqueous poly(N-isopropylacrylamide) (PNIPAM) with a molecular weight of 1.24 × 105 by small-angle X-ray scattering (SAXS) as well as static and dynamic light scattering (SLS and DLS). Those scattering experiments provide us with the average size and size distribution of concentrated-phase droplets and the concentration cconc of the coexisting concentrated phase. While the average droplet size is almost constant above 35 °C in the temperature-scan experiments, it is a decreasing function of temperature above 35 °C in the temperature-jump experiments. This heating rate dependence of the average droplet size arises from the fact that concentrated-phase droplets in the aqueous PNIPAM solution grow only in a limited temperature range (31.5-35 °C). The scattering results on the temperature dependence of cconc are combined with previously reported results of turbidity and DSC, giving the phase diagram of the Type II phase behavior with the off-zero critical point at high molecular weight.

DOI： 10.1021/acs.langmuir.1c01917

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.jpcb.1c01864

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

DOI： 10.1002/marc.202000585

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その他リンク： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/marc.202000585

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）  

DOI： 10.1021/acs.langmuir.0c02032

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-V C H VERLAG GMBH  

Recent studies show that calix[4]arene-based micelles are monodisperse with defined N-agg values chosen from 4, 6, 8, 12, 20, and 32. Interestingly, all these numbers coincide with the face numbers of Platonic solids, so they are called "Platonic micelles." As long as a certain geometric condition is fulfilled, any amphiphilic molecule can form a Platonic micelle. The preferred N-agg values are explained in relation to the mathematical Tammes problem, namely, how to obtain the best coverage of a sphere's surface with multiple identical circles. The coverage ratio can be calculated and produces maxima at 4, 6, 12, 20, and 32, coinciding with the observed N-agg values. In this feature article, Platonic micelles as well as their morphological transition by controlling pH, salt, temperature, and electrostatic interactions are summarized.

DOI： 10.1002/marc.202000227

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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：SOC FIBER SCIENCE TECHNOLOGY  

Poly[N-(2-Hydroxypropyl)methacrylamide] (PHPMA) shows excellent biocompatibility and thus is expected to be used as a carrier in a drug delivery system. In this study, we investigated how the difference in the monomer structure influences the sequence in copolymers composed of HPMA and monomers (MA-ahNHNH-Boc and MA-NHNH-Boc); the size of MA-ah-NHNH-Boc is larger than that of MA-NHNH-Boc by the alkyl chain (CH2)5 spacer. Because the obtained copolymers showed a phase separation behavior upon heating,we also investigated this phase separation behavior by turbidimetry and the molecular dimension in dilute aqueous solution by small-angle X-ray scattering (SAXS). Consequently, we found that the difference between the monomers (MA-ah-NHNH-Boc or MA-NHNH-Boc) significantly influences the monomer sequence in copolymer chains, the cloud point temperature, and the chain dimension in aqueous solution.

DOI： 10.2115/fiberst.2020-0033

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

By introducing strong directed hydrogen bonds to an amphiphilic polymer, we demonstrate that phase transitions from spherical to cylindrical morphologies in aqueous solutions can significantly be shifted to favor the assembly of supramolecular polymer bottlebrushes. In water, a forced self-assembly of polymers into cylindrical structures remains a challenge as the often required hydrophobic shielding induces forces, which tend to minimize the surface area. The herein presented novel benzene trisureas can overcome these limitations due to strong hydrogen bonds and alter the morphology to cylinders despite an unfavorable packing parameter, which dominated the previously reported trisamide analogues. The systematic variation of composition and architecture revealed that a transition to spherical morphologies still occurs, but the phase-transition boundaries appear to be shifted to tolerate larger hydrophilic polymer chains. The strength of the directing interactions appears to be decisive for the shift, though we additionally observed that any restrictions of lateral aggregation can diminish the effect of the directing hydrogen bonds. Overall, the straightforward synthesis and versatile design render the presented systems an interesting blueprint for the development of more advanced supramolecular polymer bottlebrushes and multifunctional nanostructures.

DOI： 10.1021/acs.macromol.0c01361

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER  

For designing nanoparticles as drug carriers, a covalently crosslinked structure is necessary for the structural stability in vivo. In this study, we prepared core crosslinked nanoparticles through the formation of nanoemulsions stabilized by poly(ethylene glycol) (PEG)-bearing surfactants. The structural characteristics of these particles were carefully evaluated using small-angle scattering techniques including dynamic, static, X-ray, and neutron scattering. The particles demonstrated high stability even in vivo, with the suppression of premature drug release owing to the crosslinked structure. Interestingly, the ability to retain encapsulated molecules was dependent on the molecular weight of PEG in vivo, presumably due to the difference in the crowding density of PEG chains at the outermost surface. This suggests that conferring structural stability via a core crosslinked structure is surely important, but we also need to consider controlling the crowding density of the hydrophilic polymer chains in the particle shell when designing drug carriers.

DOI： 10.1016/j.jconrel.2020.05.035

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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：AMER CHEMICAL SOC  

Small-angle scattering is a powerful tool to investigate micellar structure, and a model form factor proposed by Pedersen and Gerstenberg [Pedersen, J. S.; Gerstenberg, M. Macromolecules 1996, 29, 1363-1365] has been used quite frequently to analyze experimentally obtained scattering data of block copolymer micelles. Their model consists of a spherical core and the Gaussian corona chains attached to the core surface; the corona chains are considered to be approximately continuously (evenly) distributed on the core surface. In this paper, we present a micellar form factor model in which the corona chains are discretely distributed on the core surface. Our proposed discrete model was found to deviate from the Pedersen-Gerstenberg model as well as another model [Svaneborg, C.; Pedersen, J. S. Phys. Rev. E 2001, 64, R01802.], which incorporates the approximate interference effect between the corona chains, in conditions in which the scattering from the corona chains is stronger than that from a core with lower number density of the corona chains.

DOI： 10.1021/acs.jpcb.0c04120

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ROYAL SOC CHEMISTRY  

Reinforcement of the in vivo structural stability of polymer-based nanoparticles such as polymeric micelles has been achieved via covalently crosslinked structures. Herein, we report new core crosslinked nano-particles prepared via an o/w nano-emulsion composed of difunctional polymerizable oil monomers stabilized by a poly(ethylene glycol) (PEG)-bearing surfactant. The obtained PEG-tethered core crosslinked nanoparticles are named furry nanoparticles (f-NPs). The f-NPs structure was evaluated using light scattering (LS; both static SLS and dynamic DLS), small-angle X-ray scattering, and transmission electron microscopy. The f-NPs' size could be easily controlled by changing the amount of oil monomer, which also affected dye loading and releasing behavior. Employing a disulfide-based oil monomer, we could endow the f-NPs with sensitivity to reduction, demonstrating destabilization in a reducing environment with a high glutathione level matching that in tumors. The structural stability of f-NPs in vivo was very high compared with that of a micellar system, resulting in prolonged circulation in the bloodstream. Interestingly, the in vivo stability might depend on the crowding density of PEG chains at the outermost surface, even though the structural stability was guaranteed by the crosslinked structure. This study demonstrates the promising synthesis of core crosslinked nanoparticles and their potential as drug carriers.

DOI： 10.1039/d0py00610f

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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）  

DOI： 10.1039/d0py00426j

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.jpcb.0c00934

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/s41428-019-0296-y

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ROYAL SOC CHEMISTRY  

Upon extending a hydrophobic polymer chain from the end of a preceding hydrophilic chain in aqueous solutions, the resultant block copolymers may eventually undergo self-assembly. Further chain propagation continues in the newly formed hydrophobic polymer rich domain. This process is often referred to as polymerization-induced self-assembly (PISA). Its kinetics are determined by the polymerization and the micelle formation/growth, which may influence each other, possibly leading to a highly complex process of structural development. In this study, we examined PISA in aqueous solution on the reversible addition fragmentation chain transfer (RAFT) dispersion polymerization of poly(N-acryloylmorpholine)-b-poly(N-acryloylthiomorpholine). Using in situ small-angle X-ray scattering (SAXS) and nuclear magnetic resonance spectroscopy (NMR), the polymerization and micelle formation were observed. In the analysis, because the time scale of the micelle formation/growth is much shorter than that of the polymerization, the polymerization and micelle fomarion/growth can be decoupled. Thus, these were separately analyzed in depth, and a combination of the kinetics of RAFT polymerization and the simple scaling theory of the micellar structures can quantitatively describe the overall micellar structural development during PISA. This study provides an unprecedented insight into the processes underlying PISA and deepens our quantitative understanding of it.

DOI： 10.1039/c9py01810g

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.langmuir.0c00861

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/d0py01185a

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ROYAL SOC CHEMISTRY  

When the micellar aggregation number (N-agg) is sufficiently small (N-agg o 30), the micelle shows an abnormal aggregation behavior: monodispersity without any distribution in N-agg, whose values coincide with the vertex number of a regular polyhedral structure, i.e., they are termed Platonic solids. Micelles with these characteristics are named "Platonic micelles''. In this study, we investigated the aggregation behavior of calixarene-based micelles bearing primary amines-the first example of Platonic micelles-with increasing alkyl chain length by small-angle X-ray scattering, asymmetrical flow field flow fractionation coupled with multiangle light scattering, and analytical ultracentrifugation measurements. Morphological transition of the micelles from spherical to cylindrical was observed when the alkyl chain length was increased in this calixarene-based micellar system, which is similar to the case of conventional systems and is acceptable in terms of the packing parameter principle. However, although the micellar N-agg normally increases with an increase in the alkyl chain length, the structure of calixarene-based Platonic micelles bearing butyl (C4), heptyl (C5), and hexyl (C6) chains remains at 12-mer. This is presumably due to the relationship between the thermodynamic stability of the Platonic micelles and the coverage ratio defined by the Tammes problem.

DOI： 10.1039/c9sm00076c

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acsabm.9b00047

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.langmuir.8b04204

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jcis.2018.09.044

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ROYAL SOC CHEMISTRY  

The mixture ratios were used as a factor for aggregation number (N-agg) determination in binary mixtures of calix[4]arene surfactants. Platonic micelles having different N-agg were prepared by adjusting the ratio of oppositely charged compounds.

DOI： 10.1039/c8cc09621j

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

We investigated the formation kinetics of a single monolayer nanotube from bolaamphiphiles (consisting of a sugar residue, an alkyl chain, and an amino group) in solution. In this bolaamphiphile, a transition from a monomerically dispersed state to the nanotube takes place by changing the solvent condition. This transition was induced by fast mixing with a stopped-flow apparatus. From just after the mixing, this transition process was monitored in situ by time-resolved small-angle X-ray scattering. In this manner, we were able to derive the direct structural information as a function of time during the nanotube formation. The results revealed that disklike aggregates initially formed, which then grew and closed to produce a tubular structure.

DOI： 10.1021/acs.jpcb.9b01746

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ROYAL SOC CHEMISTRY  

Among the many studies on micelles, dating back more than 100 years, we first found a series of monodisperse micelles: spherical micelles made from calix[4]arene surfactants exhibited monodispersity in aggregation number (N-agg) with values of 4, 6, 8, 12, and 20. We named these Platonic micelles because these values coincided with the face numbers of the Platonic solids. The preferred N-agg values were explained in relation to the mathematical Tammes problem: how to obtain the best coverage of a sphere surface with multiple identical circles. In this paper, we synthesized poly(ethylene glycol)-attached surfactants and carried out small-angle X-ray scattering (SAXS) and analytical ultracentrifugation (AUC) to determine the N-agg. We found that these polymeric surfactants also formed monodispersed micelles and N-agg discontinuously increased from 20 to 24, and then 32 with increasing the alkyl carbon numbers from 9 to 11 continuously. The determined N-agg was greater than 20 and the Platonic solid numbers. We assumed that the preferred N-agg values could be explained in relation to the Tammes problem as well.

DOI： 10.1039/c9sm00943d

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1295/koron.2018-0052

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

When a negatively charged sulfonic or a positively charged amine group is attached to calix[4]arene surfactants, denoted as SCal7 and QACal7, respectively, each system forms monodispersed spherical micelles with a defined aggregation number. We postulated that these defined monodisperse aggregations can be adjusted in terms of the coverage, that is, how efficiently can a spherical surface (, hydrophobic domain) be covered with identical caps (hydrophilic headgroup). We carried out small-angle X-ray scattering (SAXS), as well as titration calorimetry and dynamic light scattering (DLS), to observe the morphologies of the mixtures of these two components. The calorimetry showed a 1:1 stoichiometric exothermic reaction with a rather large binding constant. This means that, once the twin is formed from QACaI7 and SCal7, these components hardly separate. SAXS showed that the spherical micelles changed to cylindrical ones and then to vesicle shapes as the composition reached a ratio of 1:1. At some intermediate compositions, mixtures of cylinders and plates (or spheres) were observed, which were confirmed by dynamic light scattering. We assume that the twin has a larger packing parameter than the individuals because of the cancellation of the charges between the sulfonic and the amine groups, and thus, the increase of the twin composition induces the entire morphology change, as expected from the packing parameter principle. In the present case, the coverage may be a secondary factor determining the morphology.

DOI： 10.1021/acs.langmuir.8b02542

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.langmuir.8b01168

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.macromol.8b00101

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

When the micellar aggregation number (N-agg) is small enough (<30), the N-agg matches the value of vertexes of a regular polyhedron: Platonic solids, and demonstrates perfect monodispersity. These micelles are named Platonic micelles and are particularly found in the system of calix[4]arene-based micelles due to the rigid structure of the backbone molecule. Although sulfonatocalix[4]arene-based micelles are among the most studied host molecules in supramolecular chemistry, their micellar properties as Platonic micelles have thus far been overlooked. In this study, we prepared various sulfonatocalix[4]arene-based amphiphiles bearing alkyl chains with different lengths and investigated their aggregation behavior. When the amphiphiles formed spherical micelles, they demonstrated monodispersity in terms of N-agg, whose value changed from 4 to 17, and then to 24, upon increasing the carbon number in each alkyl chain from CS to C6, and then to C7, respectively. Although the numbers 17 and 24 do not match the vertices of regular polyhedra, these values can be reasonably explained by the Thomson problem, which considers the Coulomb potential for calculating the best packing on a sphere with multiple identical spherical caps. This study describes rediscovery of the monodispersity of sulfonatocalix[4]arene-based micelles, which is consistent with the idea of Platonic micelles.

DOI： 10.1021/acs.langmuir.8b00802

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/c7sm02028g

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記述言語：英語  

DOI： 10.1039/c8sm90014k

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/c7cp03905k

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その他リンク： http://orcid.org/0000-0003-2168-9436

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

The aggregation number of classical micelles exhibits a certain distribution, which is a recognizable feature of conventional micelles. However, we recently identified perfectly monodisperse calix[4]arene-based micelles whose aggregation numbers agree with the vertex numbers of regular polyhedra, that is, Platonic solids, and thus they are named Platonic micelles. Regarding our hypothesis of the formation mechanism of Platonic micelles, both repulsive interactions including steric hindrance and electrostatic repulsions among the headgroups are important for determining their aggregation number; however, neither of these is necessarily needed to consider. In this study, we employed polyethylene glycols (PEGs) as the nonionic headgroup of calix[4]arene-based amphiphiles to study the effects of only repulsive interactions caused by steric hindrance on the formation of Platonic micelles. The amphiphiles containing relatively low-molecular-weight PEGs (550 or 1000 g mol(-1)) form dodecamer or octamer micelles, respectively, with no variation in the aggregation number. However, relatively high-molecular-weight PEGs (2000 g mol(-1)) produce polydispersed micelles with a range of aggregation number. PEG 2000 exhibits a greater affinity for water than PEG 550 and 1000, resulting in fewer hydrophobic interactions in micelle formation, as indicated by the drastic increase of the critical micelle concentration (CMC) value in the PEG 2000 system. The instability of the structure of PEG(2k)CaL5 micelles might contribute to the higher mobility of PEG in the micellar shell, resulting in a non-Platonic aggregation number with polydispersity.

DOI： 10.1021/acs.langmuir.7b02196

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その他リンク： http://orcid.org/0000-0003-2168-9436

記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1002/anie.201702260

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その他リンク： http://orcid.org/0000-0003-2168-9436

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1246/cl.170032

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その他リンク： http://orcid.org/0000-0003-2168-9436

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

We have prepared a new calix[4]arene-based lipid containing glutamic acid as the hydrophilic group. The alpha- amine and the gamma-carboxylic acid groups of the glutamic acid moiety allowed a continuous change in the state of the headgroup from cationic to zwitterionic and then to anionic with increasing pH. Accompanying this headgroup change, micelles of the lipid underwent a morphological transformation from spherical to cylindrical and again to spherical. The morphological transition was ascribed to the change in the lipid conformation corresponding to the pH conditions. Interestingly, at acidic and basic pH, the spherical micelles demonstrated monodispersity in terms of the aggregation number, Which agreed with the vertex numbers of Platonic solids, indicating the formation of Platonic micelles. At acidic and basic pH, the lipid conformations were almost identical, but there was a slight difference in the hydrophilic volume, which might affect the packing behavior of the lipid in micelles and account for the difference in the aggregation number. This Study clearly demonstrates the precise pH-controllable aggregation number of micelles, which belong to the Platonic micelle systems.

DOI： 10.1021/acs.langmuir.7b00603

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その他リンク： http://orcid.org/0000-0003-2168-9436

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/pj.2016.124

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その他リンク： http://orcid.org/0000-0003-2168-9436

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.jpclett.6b02957

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その他リンク： http://orcid.org/0000-0003-2168-9436

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/pj.2016.110

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/pj.2016.49

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.macromol.6b00308

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

We have investigated the self-assembly in dilute aqueous solutions of a mixture of an anionic-neutral block copolymer (AP) and a cationic-neutral block copolymer (MP) by changing the added sodium chloride (NaCl) concentration C-S or electrostatic interactions among oppositely charged blocks, by direct observation, optical and electron microscopies, and small-angle X-ray scattering. The ratio of the charged to neutral block chain lengths was ca. 10., and the total copolymer concentration and the mixing ratio (the mole fraction of the MP charge unit in the total charge units) of AP and MP were fixed to be 0.005 g/cm(3) and 0.6, respectively. With decreasing C-S from 2 to 0 M, we have found reentrant one-phase, two-phase, one-phase transitions in the aqueous solution of the AP-MP mixture. The two-phase to one-phase transition at C-S similar to 0.5 M arises from the competition between the macroscopic phase transition and micellization, which is the first observation in dilute block copolymer solutions. Moreover, we have found a micelle morphology transition from the bilayer vesicle to the cylindrical micelle with further decreasing C-S from 0.5 M to lower than 0.05 M.

DOI： 10.1021/acs.macromol.5b01368

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/ma501538t

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/ma3020992

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/ma300969w

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

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記述言語：英語   会議種別：口頭発表（一般）  

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