ASAI Makoto

写真a

Affiliation

Research Centers and Institutes, Keio University Global Research Institute (Mita)

Position

Project Professor (Non-tenured)

E-mail Address

E-mail address

Related Websites

External Links

Message from the Faculty Member 【 Display / hide

  • I received B.S, and Ph.D. in Applied Physics and Physico-Informatics at Keio University in 2005 and 2009 working with Prof. Yasuhiro Koike on the development of novel polymer optical fibers with the highest bandwidth in the world. I was selected as a Research Fellow of the Japan Society for the Promotion of Science for 2009-2011. After working with Prof. Mitsuhiro Shibayama in University of Tokyo on the gelation mechanism of Tetra-PEG gel in simulation and experiment, I joined the Kumar group as a postdoctoral research scientist in Spring 2013. My current project is self-assembly of polymer grafted nanoparticles. From May 2017 I joined Keio University as Project Assistant Professor with joint appointment as research scientist at Columbia University.

Career 【 Display / hide

  • 2019.10
    -
    Present

    Arclev, Inc., Co-Founder / CEO

  • 2013.05
    -
    Present

    Columbia University in the City of New York, Chemical Engineering, Research Scientist

  • 2017.05
    -
    2019.03

    Keio University, Faculty of Science and Technology, Project Assistant Professor

  • 2011.04
    -
    2013.03

    The University of Tokyo, Institute of The Solid State Physics, Research Scientist

  • 2009.04
    -
    2011.03

    Keio University, Faculty of Science and Technology, Research Fellow of the Japan Society for the Promotion of Science

Academic Background 【 Display / hide

  • 2001.04
    -
    2005.03

    Keio University, Faculty of Science and Technology, Applied Physics and Physico-Informatics

    Japan, University, Graduated, Other

  • 2005.04
    -
    2006.09

    Keio University, School of Integrated Design Engineering

    Japan, Graduate School, Completed, Master's course

  • 2006.09
    -
    2009.03

    Keio University, School of Integrated Design Engineering

    Japan, Graduate School, Completed, Doctoral course

Academic Degrees 【 Display / hide

  • B.S (Engineering), Keio University, Coursework, 2005.03

  • M.S (Engineering), Keio University, Coursework, 2006.09

  • Ph.D (Engineering), Keio University, Coursework, 2009.03

 

Research Areas 【 Display / hide

  • Biological physics/Chemical physics/Soft matter physics

Research Keywords 【 Display / hide

  • Soft Matter, Self-Assembly, Nanoparticles, Active Matter, Gels, Polymers, Glass Transition

 

Papers 【 Display / hide

  • Cluster growth from a dilute system in a percolation process

    Fujinaga I., Yasuda T., Asai M., Chung U.i., Katashima T., Sakai T.

    Polymer Journal (Polymer Journal)  52 ( 3 ) 289 - 297 2020.03

    ISSN  00323896

     View Summary

    © 2019, The Society of Polymer Science, Japan. Abstract: The gelation process has been explained in the framework of percolation models. Although the percolation models accurately predict the gelation behaviors above the overlap concentration of prepolymers (c*0), they do not predict the gelation behaviors below c*0. We measured the osmotic pressure during the gelation of a series of model polymer gels, namely, tetra-polyethylene glycol (PEG) gels. The osmotic pressure decreased during the gelation reaction and was constant after the sol–gel transition. These results suggest that the clusters grow and fill the system at the sol–gel transition point. As a result, the gels behaved as semidilute systems regardless of the initial polymer concentration. This representation of the sol–gel transition at the overlap condition of the critical clusters corresponds well to the aggregation process predictrion. These results will help better understanding of general percolation problems in the dilute regime.

  • Accurate Estimation of the Polymer Coverage of Hairy Nanoparticles

    ASAI MakotoZHAO DanKUMAR K Sanat

    Soft Matter (The Royal Society of Chemisry)  14 ( 38 ) 7906 - 7915 2018.08

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  1744683X

     View Summary

    © The Royal Society of Chemistry. Understanding and predicting the mechanisms underpinning the self-assembly of polymer-grafted nanoparticles (PGNPs) are important for controlling the engineering applications of these novel materials. The self-assembly of these materials is driven by their surfactancy, i.e., by the fact that the (inorganic) nanoparticles energetically dislike the (organic) polymer tethers. In previous work we developed a model in which a grafted polymer chain was treated as a rigid equivalent sphere (ES) which was impenetrable to the NPs, but completely penetrable to other ESs. This description, along with a geometric analogy with patchy particles, allowed us to facilely explain the self-assembly of PGNPs. However, since we model an ES as being completely penetrable to other ESs but impenetrable to the NPs the physical correspondence between a “real” grafted polymer and an ES is not clear. The application of the ES model to experiments and to computer simulations has therefore seen limited success, and only qualitative agreement has been obtained. In this paper, we develop a more realistic description, termed the modified ES (mES) model, based on the work of Daoud and Cotton on curved polymer brushes, which takes the impenetrability of the individual chain monomers into account. While this approach increases the complexity of our formalism, we find that the resulting mES model quantitatively captures computer simulation results on the structure of the PGNPs and also quantitatively explains their self-assembly over a broad range of conditions.

  • Surface Fluctuations Dominate the Slow Glassy Dynamics of Polymer-Grafted Colloid Assemblies

    ASAI MakotoCACCIUTO AngeloKumar K Sanat

    ACS Central Science (American Chemical Society)  4 ( 9 ) 1179 - 1184 2018.08

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  23747943

     View Summary

    © 2018 American Chemical Society. Colloids grafted with a corona layer of polymers show glassy behavior that covers a wide range of fragilities, with this behavior being tunable through variations in grafting density and grafting chain length. We find that the corona roughness, which is maximized for long chain lengths and sparse grafting, is directly correlated to the concentration-dependence of the system relaxation time (fragility). Relatively rougher colloids result in stronger liquids because their rotational motions become orientationally correlated across the whole system even at low particle loadings leading to an essentially Arrhenius-like concentration-dependence of the relaxation times near the glass transition. The smoother colloids do not show as much orientational correlation except at higher densities leading to fragile behavior. We therefore propose that these materials are an ideal model to study the physical properties of the glass transition.

  • Impact of the Distributions of Core Size and Grafting Density on the Self-Assembly of Polymer Grafted Nanoparticles

    Bachhar, Nirmalya; Jiao, Yang; Asai, Makoto; Akcora, Pinar; Bandyopadhyaya, Rajdip; Kumar, Sanat

    Macromolecules (American Chemical Society)  50 ( 19 ) 7730 - 7738 2017.09

    Research paper (scientific journal), Joint Work, Accepted

  • Polymer-Grafted Nanoparticle Membranes with Controllable Free-Volume

    Connor Bilchak, Eileen Buenning, Makoto Asai, Kai Zhang, Christopher Durning, Sanat Kumar, Yucheng Huang, Brian Benicewicz, David Gidley, Shiwang Cheng, Alexei Sokolov, Matteo Minelli, Ferruccio DoghieriASAI Makoto

    Macromolecules (American Chemical Society)  50 ( 18 ) 7111 - 7120 2017.09

    Research paper (scientific journal), Joint Work, Accepted

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • Entropy-Driven Self-Assembly of Soft Materials

    2020.04
    -
    2025.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, 浅井 誠, Grant-in-Aid for Scientific Research (C), Principal Investigator

Awards 【 Display / hide

  • International Young Scientist Fellowship

    2018.04, Chinese Academy of Science, Institute of Physics

    Type of Award: International Academic Awards.  Country: China

  • International Young Scientist Fellowship

    2018.04, Chinese Academy of Science, Institute of Physics

    Type of Award: International Academic Awards.  Country: China

  • the Marie Sklodowska-Curie Actions Seal of Excellence

    Makoto Asai, David Wales, 2018.03, European Commission, Entropy Driven Self-Assembly of Soft Materials

    Type of Award: International Academic Awards.  Country: Brussel

  • the Marie Sklodowska-Curie Actions Seal of Excellence

    Makoto Asai, David Wales, 2018.03, Entropy Driven Self-Assembly of Soft Materials

    Country: Brussel

  • the Marie Sklodowska-Curie Actions Seal of Excellence

    Makoto Asai, Daan Frenkel, 2017.04, European Commission, Predicting polymorphism in self-assembling soft materials

    Type of Award: International Academic Awards.  Country: Brussels

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Courses Taught 【 Display / hide

  • INTERNSHIP D(GLOBAL ENVIRONMENTAL SYSTEM LEADERS PROGRAM)

    2021

  • INTERNSHIP C(GLOBAL ENVIRONMENTAL SYSTEM LEADERS PROGRAM)

    2021

  • INTERNSHIP B(GLOBAL ENVIRONMENTAL SYSTEM LEADERS PROGRAM)

    2021

  • INTERNSHIP A(GLOBAL ENVIRONMENTAL SYSTEM LEADERS PROGRAM)

    2021

  • FIELDWORK B(GLOBAL ENVIRONMENTAL SYSTEM LEADERS PROGRAM)

    2021

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Courses Previously Taught 【 Display / hide

  • 環境情報システム構築法

    Keio University, 2018, Spring Semester, Major subject, Lecture, Lecturer outside of Keio, 20people

  • Environmental Information System Architecture

    Keio University, 2017, Spring Semester, Major subject, Lecture, Lecturer outside of Keio, 1h, 20people

 

Social Activities 【 Display / hide

  • Reviewer of Japan Society for the Promotion of Science Postdoctoral Fellowship for Researchers in US and EU

    2016.06
    -
    Present

Memberships in Academic Societies 【 Display / hide

  • American Physical Society, 

    2013
    -
    Present