Faculty Profiles - NAKANISHI Kazuki

Global wellposedness for the energy-critical Zakharov system below the ground state Reviewed

Candy T., Herr S., Nakanishi K.

Advances in Mathematics Vol. 384 2021.6

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Advances in Mathematics

The Cauchy problem for the Zakharov system in the energy-critical dimension d=4 is considered. We prove that global well-posedness holds in the full (non-radial) energy space for any initial data with energy and wave mass below the ground state threshold. The result is based on a Strichartz estimate for the Schrödinger equation with a potential. More precisely, a Strichartz estimate is proved to hold uniformly for any potential solving the free wave equation with mass below the ground state constraint. The key new ingredient is a bilinear (adjoint) Fourier restriction estimate for solutions of the inhomogeneous Schrödinger equation with forcing in dual endpoint Strichartz spaces.

DOI： 10.1016/j.aim.2021.107746

The Correlation between Fluid Distribution and Swelling or Subjective Symptoms of the Trunk in Lymphedema Patients: A Preliminary Observational Study Reviewed

Hisano F., Niwa S., Nakanishi K., Mawaki A., Murota K., Fukuyama A., Takeno Y., Watanabe S., Fujimoto E., Oshima C.

Lymphatic Research and Biology Vol. 19 ( 3 ) page： 269 - 273 2021.6

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Lymphatic Research and Biology

Background: Manual lymph drainage (MLD) is one of the common treatments for breast cancer-related lymphedema (BCRL). Although the primary goal of MLD is to drain the excessive fluid accumulated in the affected upper limb and trunk to an area of the body that drains usually, the use of MLD is decided based on swelling and subjective symptoms, without assessing whether there is fluid accumulated in the affected region. The purpose of this study was to examine truncal fluid distribution in a sample of BCRL patients and investigate any correlation between such fluid distribution and swelling or subjective symptoms. Methods and Results: An observational study was conducted with 13 women who had unilateral, upper extremity BCRL. Fluid distribution was evaluated by using two magnetic resonance imaging (MRI) sequences: half-Fourier acquisition single-shot turbo spin echo and three-dimensional double-echo steady-state. The presence of swelling was determined by lymphedema therapists, and subjective symptoms were measured by using a visual analog scale. On MRI, no participants had any free water signals in the trunk. However, seven had swelling and all 13 had some kind of subjective symptoms on the affected side of their trunk. Conclusions: These results suggest that swelling and subjective symptoms do not correlate with the presence of truncal fluid. For such cases, a different approach than MLD may be needed to address truncal swelling and related subjective symptoms. Checking for the presence of fluid in the truncal region may help MLD be used more appropriately.

DOI： 10.1089/lrb.2020.0075

Preparation of hierarchically porous spinel CoMn2O4 monoliths via sol-gel process accompanied by phase separation Reviewed

Xuanming Lu, Kazuyoshi Kanamori, George Hasegawa, Kazuki Nakanishi

JOURNAL OF THE AMERICAN CERAMIC SOCIETY Vol. 104 ( 6 ) page： 2449 - 2459 2021.6

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

Cobalt manganite-based hierarchically porous monoliths (HPMs) with three-dimensionally (3D) interconnected macropores and open nanopores have been prepared via the sol-gel process accompanied by phase separation. The controlled hydrolysis and polycondensation of the brominated metal alkoxides, which are generated from an incomplete reaction between epichlorohydrin and MBr2 (M = Co and Mn) in N,N-dimethylformamide (DMF), form a monolithic gel based on the two divalent metal cations. The dual-polymer strategy using polyvinylpyrrolidone (PVP) and poly(ethylene oxide) (PEO) effectively induces the spinodal decomposition, where PVP and PEO are preferentially distributed to the gel phase and fluid phase, respectively, resulting in a porous gel characterized by the co-continuous structure. The effects of DMF and PVP on the porous morphology derived from the phase separation have been systematically studied. Calcination of the as-dried gels allows for the crystallization into the spinel phase yielding hierarchically porous CoMn2O4 monoliths, which have been examined in detail by the structural and compositional analyses.

DOI： 10.1111/jace.17662

Highly porous melamine-formaldehyde monoliths with controlled hierarchical porosity toward application as a metal scavenger Reviewed

Yuki Nakanishi, Yosuke Hara, Riichi Miyamoto, Kazuki Nakanishi, Kazuyoshi Kanamori

Materials Advances Vol. 2 ( 8 ) page： 2604 - 2608 2021.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Royal Society of Chemistry (RSC)

<p>Hierarchically porous melamine-formaldehyde monoliths were prepared <italic>via</italic> sol–gel accompanied by phase separation, followed by a hydrothermal process. The obtained monoliths showed efficient adsorption of precious metal ions.</p>

DOI： 10.1039/d1ma00034a

Tunable and Well-Defined Bimodal Porous Model Electrodes for Revealing Multiscale Structural Effects in the Nonaqueous Li–O2 Electrode Process Reviewed

Yosuke Hara, Manai Ono, Shoichi Matsuda, Kazuki Nakanishi, Kazuyoshi Kanamori, Ken Sakaushi

The Journal of Physical Chemistry C Vol. 125 ( 2 ) page： 1403 - 1413 2021.1

Hierarchically porous monoliths based on low-valence transition metal (Cu, Co, Mn) oxides: Gelation and phase separation Reviewed

Lu, X., Kanamori, K., Nakanishi, K.

National Science Review Vol. 7 ( 11 ) page： 1656 - 1666 2020.11

Hierarchically porous monoliths prepared via sol–gel process accompanied by spinodal decomposition Reviewed

Xuanming Lu, George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi

Journal of Sol-Gel Science and Technology Vol. 95 ( 3 ) page： 530 - 550 2020.9

On-site formation of small Ag nanoparticles on superhydrophobic mesoporous silica for antibacterial application Reviewed

Zhu Yang, Chunhua Wu, Kazuyoshi Kanamori, Toshiyuki Kamei, Toyoshi Shimada, Kazuki Nakanishi

New Journal of Chemistry Vol. 44 ( 32 ) page： 13553 - 13556 2020.8

Superhydrophobic highly flexible doubly cross-linked aerogel/carbon nanotube composites as strain/pressure sensors Reviewed

Guoqing Zu, Xiaodong Wang, Kazuyoshi Kanamori, Kazuki Nakanishi

JOURNAL OF MATERIALS CHEMISTRY B Vol. 8 ( 22 ) page： 4883 - 4889 2020.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

We report novel superhydrophobic highly flexible composites based on a doubly cross-linked (DCL) aerogel and carbon nanotubes (CNTs) for strain/pressure sensing. The DCL aerogel/CNT composite is prepared by radical polymerization of vinylmethyldimethoxysilane and vinyldimethylmethoxysilane, respectively, followed by hydrolytic co-polycondensation of the obtained polyvinylmethyldimethoxysilane and polyvinyldimethylmethoxysilane, combined with the incorporation of CNTs. Benefiting from the flexible methyl-rich DCL structure of the aerogel and conductive CNTs, the resultant DCL aerogel/CNT composite combines superhydrophobicity, high compressibility, high bendability, high elasticity, and strain- and pressure-sensitive conductivity. We demonstrate that the composite can be applied as a high-performance strain/pressure sensor for the detection of arterial pulse waves and joint bending with high sensitivity and high durability against humidity.

DOI： 10.1039/c9tb02953b

Superelastic Triple-Network Polyorganosiloxane-Based Aerogels as Transparent Thermal Superinsulators and Efficient Separators Reviewed

Guoqing Zu, Kazuyoshi Kanamori, Xiaodong Wang, Kazuki Nakanishi, Jun Shen

CHEMISTRY OF MATERIALS Vol. 32 ( 4 ) page： 1595 - 1604 2020.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

We report new polyorganosiloxane aerogels with superhydrophobicity, high elasticity, and high bendability based on polyvinyl-poly(dimethylsiloxane) (PVPDMS)/polymethylsilsesquioxane (PMSQ). They are synthesized by a radical polymerization/co-polycondensation strategy that involves radical polymerization of vinyldimethylmethoxysilane to obtain chainlike polyvinyldimethylmethoxysilane (PVDMMS) polymers followed by hydrolytic co-polycondensation of PVDMMS polymers and methyltrimethoxysilane combined with ambient pressure drying without any post-gelation modifications. The resultant PVPDMS/PMSQ aerogels exhibit a highly tunable triple-network structure consisting of flexible inter-cross-linked hydrocarbon polymers, poly(dimethylsiloxane), and PMSQ The aerogels with a low content of PVPDMS exhibit small pore sizes (2-80 nm), good transparency, high surface areas, and thermal superinsulation (lambda = 0.0148 W m(-1) K-1), while those with a high content of PVPDMS exhibit large pore sizes (100 nm-3 mu m) and excellent selective absorption for organic liquids. In addition, incorporation of graphene oxide (GO) in PVPDMS/PMSQ aerogels can afford highly flexible PVPDMS/PMSQ/GO composite aerogels, which show efficient separation of three-component water/oil/dye mixtures. These aerogels are promising in the practical applications of thermal insulation, absorption/adsorption, and separation.

DOI： 10.1021/acs.chemmater.9b04877

Self‐Assembly of Metal–Organic Frameworks into Monolithic Materials with Highly Controlled Trimodal Pore Structures Reviewed

Colorless Transparent Melamine-Formaldehyde Aerogels for Thermal Insulation Reviewed

Nakanishi, Y., Hara, Y., Sakuma, W., Saito, T., Nakanishi, K., Kanamori, K.

ACS Applied Nano Materials Vol. 3 ( 1 ) page： 49 - 54 2020.1

Yosuke Hara, Kazuyoshi Kanamori, Kazuki Nakanishi

Angewandte Chemie International Edition Vol. 58 ( 52 ) page： 19047 - 19053 2019.12

Resilient, fire-retardant and mechanically strong polyimide-polyvinylpolymethylsiloxane composite aerogel prepared via stepwise chemical liquid deposition Reviewed

Ze Zhang, Xiaodong Wang, Guoqing Zu, Kazuyoshi Kanamori, Kazuki Nakanishi, Jun Shen

MATERIALS & DESIGN Vol. 183 2019.12

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

Resilient, fire-retardant and mechanically strong polyimide-polyvinylpolymethylsiloxane (PI-PVPMS) composite aerogels have been prepared via stepwise chemical liquid deposition (SCLD). The synthesis is based on the formation of PI-PVPMS crosslinked network structure with (3-aminopropyl)trimethoxysilane (APTMS) as a coupling agent to provide reactive sites on the backbone. We successfully realize the PI in-situ growth on the whole super-flexible PVPMS gel skeleton with this simple method. The effect of APTMS amount and deposition time on the properties of final samples is deeply investigated. The resultant PI-PVPMS composite aerogels show excellent mechanical and thermal properties. They can support at least 10,000 times of their own weight and can recover 20% from a 60% of compressive strain, with an elastic modulus of 32 MPa. For thermal performance, they can maintain their structural integrity after being subjected to the alcohol lamp outer flame of around 650 degrees C for 30 min. These results together with the simple synthesis process demonstrate the potential for construction materials using PI-PVPMS composite aerogels. Furthermore, the SCLD synthesis method could also be applied to prepare other composite aerogels, especially for those containing complex polymer. (C) 2019 The Authors. Published by Elsevier Ltd.

DOI： 10.1016/j.matdes.2019.108096

Superelastic Multifunctional Aminosilane-Crosslinked Graphene Aerogels for High Thermal Insulation, Three-Component Separation, and Strain/Pressure-Sensing Arrays Reviewed

Guoqing Zu, Kazuyoshi Kanamori, Kazuki Nakanishi, Xuanming Lu, Kunhua Yu, Jia Huang, Hiroyuki Sugimura

ACS APPLIED MATERIALS & INTERFACES Vol. 11 ( 46 ) page： 43533 - 43542 2019.11

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Aerogels have attracted great interest for their unique properties, but their mechanical brittleness and poor functionality highly limit their practical applications. Herein, we report unprecedented superelastic multifunctional aminosilane-crosslinked reduced graphene oxide (AC-rGO) aerogels that are prepared via a facile and scalable strategy involving simultaneous crosslinking and reducing of graphene oxide nanosheets with different kinds of aminosilanes via C-N coupling and hydrolytic polycondensation reactions. It is found that 3-aminopropyl(diethoxy)methylsilane (APDEMS) is the better choice to enhance hydrophobicity, elasticity, and other properties of the resulting aerogels compared with (3-aminopropyl)triethoxysilane. One APDEMS molecule plays three roles as a crosslinker, a reductant, and a hydrophobizing agent. An outstanding combination of high surface area, ultralow density, superhydrophobicity, supercompressibility, superelasticity, low thermal conductivity, ultrahigh absorption capacity for organic liquids, efficient three-component separation, and strain/pressure sensing has been achieved in a single APDEMS-crosslinked rGO the first time. In addition, a flexible, highly sensitive, and moisture-resistant AC-rGO aerogel-based strain/pressure-sensing array for the effective detection of strain (0-80%)/pressure (10 Pa to 10 kPa) distributions and object shapes has been demonstrated.

DOI： 10.1021/acsami.9b16746

Thermogravimetric evolved gas analysis and microscopic elemental mapping of the solid electrolyte interphase on silicon incorporated in free-standing porous carbon electrodes Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Katsuro Hayashi

Langmuir 2019.10

Ambient-dried highly flexible copolymer aerogels and their nanocomposites with polypyrrole for thermal insulation, separation, and pressure sensing Reviewed

Guoqing Zu, Kazuyoshi Kanamori, Ayaka Maeno, Hironori Kaji, Kazuki Nakanishi, Jun Shen

Polymer Chemistry Vol. 10 ( 36 ) page： 4980 - 4990 2019.9

Language：English Publishing type：Research paper (scientific journal) Publisher：Royal Society of Chemistry ({RSC})

Aerogels exhibit unique properties, but their practical applications have been restricted by low mechanical strength and costly supercritical drying; it remains difficult to obtain highly flexible aerogels with good thermal insulation and absorption by ambient pressure drying (APD). Here, we report novel highly flexible aerogels based on the polyvinylpolymethylsiloxane (PVPMS)/polyvinyltrimethylsilane (PVTMS) co-network, which consists of inter-cross-linked hydrocarbon and siloxane polymers with dangling trimethylsilyl groups, and its nanocomposite with polypyrrole (PPy). The PVPMS/PVTMS copolymer aerogels are facilely synthesized by a consecutive radical co-polymerization and hydrolytic polycondensation strategy from two monomers vinylmethyldimethoxysilane and trimethylvinylsilane without additional cross-linkers, followed by APD without any post-gelation modification. The PPy nanocomposite aerogels are synthesized by an in situ oxidation polymerization of pyrrole in the copolymer aerogel networks, followed by APD. The resulting aerogels consist of meso- to macro-scaled pore structures with tunable skeleton and pore sizes with variable cross-linking density and bulk density. In addition, these aerogels show good hydrophobicity and high flexibility in both compression and bending. Moreover, different functionalities such as excellent thermal insulation, oil-water separation, and pressure sensing can be imparted, allowing them to exhibit potential applications in thermal insulation, separation, and sensing.

DOI： 10.1039/c9py00751b

Superhydrophobic Ultraflexible Triple-Network Graphene/Polyorganosiloxane Aerogels for a High-Performance Multifunctional Temperature/Strain/Pressure Sensing Array Reviewed

Guoqing Zu, Kazuyoshi Kanamori, Kazuki Nakanishi, Jia Huang

CHEMISTRY OF MATERIALS Vol. 31 ( 16 ) page： 6276 - 6285 2019.8

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Recently, many efforts have been made to develop various smart sensors. However, achieving flexible multifunctional sensors combining excellent sensing of temperature, strain, and pressure with a single material is still challenging. Here, we report unprecedented superhydrophobic ultraflexible reduced graphene oxide (rGO)/polyorganosiloxane aerogels and high-performance multifunctional temperature/strain/pressure sensors based on these aerogels. GO nanosheets are first cross-linked and reduced with (3-aminopropyl)triethoxysilane (APTES) to obtain APTES-modified rGO aerogels, which are then further covalently cross-linked with polyvinylmethyldimethoxysilane polymers and vinylmethyldimethoxysilane via copolycondensation to afford rGO/polyorganosiloxane aerogels. The resulting aerogels exhibit a coralline-like triple-network nanostructure consisting of rGO nanosheets, polyvinyl-poly(methylsiloxane), and poly- (vinylmethylsiloxane) that are cross-linked with each other. The aerogels combine superhydrophobicity, high compressibility, high bendability, superelasticity, excellent machinability, and temperature-, strain-, and pressure-sensitive conductivity, which is a combination not observed with traditional materials. In addition, an rGO/polyorganosiloxane aerogel-based flexible multifunctional sensing array combining sensing of temperature (20-100 degrees C), strain (in the wide range of 0.1-80%), and pressure (in the wide range of 10 Pa to 110 kPa) with high sensitivity and high durability against compression, bending, and humidity has been demonstrated for the first time.

DOI： 10.1021/acs.chemmater.9b02437

Preparation of zinc oxide with a three-dimensionally interconnected macroporous structure via a sol–gel method accompanied by phase separation Reviewed

Xuanming Lu, Kazuyoshi Kanamori, Kazuki Nakanishi

New Journal of Chemistry Vol. 43 ( 29 ) page： 11720 - 11726 2019.8

Macroporous Niobium Phosphate-Supported Magnesia Catalysts for Isomerization of Glucose-to-Fructose Reviewed

Da-Ming Gao, Yong-Bing Shen, Bohan Zhao, Qian Liu, Kazuki Nakanishi, Jie Chen, Kazuyoshi Kanamori, Huaping Wu, Zhiyong He, Maomao Zeng, Haichao Liu

ACS Sustainable Chemistry and Engineering Vol. 7 ( 9 ) page： 8512 - 8521 2019.5

Language：English Publishing type：Research paper (scientific journal) Publisher：American Chemical Society

The catalytic performance of hierarchically porous niobium phosphate (NbP) supported magnesia for the glucose isomerization to fructose, was investigated under atmospheric air atmosphere. Porous NbP showed improved support effects on MgO in comparison to other metal oxides tested for glucose isomerization. Also, the amount and distribution of basic sites were largely changed by supporting magnesia on NbP. Although the textural properties were reduced and solid acids formed on the MgO/NbP catalysts, glucose isomerization was promoted by increasing magnesium content. The maximum yield of fructose reached ∼24.6% over 40%MgO/NbP-500 with selectivity of 65.7% for 1.0 wt % glucose at 120 °C. The fructose productivity peaked as high as 13.6 g g catalyst -1 h -1 over 40%MgO/NbP-700 catalyst. The leaching of cations and anions resulted in a homogeneous system for glucose isomerization. Regeneration almost fully reactivated the catalyst to its initial activity. The MgO/NbP showed high stability under air atmosphere for 15 days, and high potential use for glucose isomerization.

DOI： 10.1021/acssuschemeng.9b00292