Details of a Researcher - KANAI Toshimitsu

Organic–inorganic hybrid particles have unique properties derived from the combination of their constituents and morphology, thereby enabling them to perform crucial functions in applications across the biomedicine, pharmaceutical, cosmetic, materials science, and engineering industries. This paper reports a method for preparing monodispersed hybrid particles comprising silica and thermosensitive poly(N-isopropylacrylamide) (PNIPAM) hydrogel particles with core–shell or snowman morphologies using a microfluidic device. Here, monodispersed droplets of sodium silicate solution are generated using a flow-focusing microfluidic device. When sodium hydrogen carbonate (NaHCO3) and N-isopropylacrylamide (NIPAM) are simultaneously transferred to the droplets, sodium silicate reacts with NaHCO3 to form core–shell structures, wherein silica-rich droplets are generated inside the NIPAM-rich droplets. The droplets are subsequently irradiated with ultraviolet (UV) light to yield monodispersed silica-PNIPAM hydrogel core–shell particles. However, when only NaHCO3 is transferred to the sodium-silicate solution droplets, a snowman-like structure comprising silica-rich and water-rich droplets is formed. Therefore, NIPAM can be transferred to water-rich droplets and photopolymerized via UV light irradiation to obtain monodispersed snowman-like silica-PNIPAM hydrogel hybrid particles. Furthermore, the PNIPAM hydrogel hybrid-particle size can be easily altered by changing the temperature to approximately the human body temperature.

Practical Preparation of Elastomer-Immobilized Non-close-Packed Colloidal Photonic Crystal Films with Various Uniform Colors

Momoko Kobori, Yuna Hirano, Mikako Tanaka and Toshimitsu Kanai

Polymers 15 ( 10 ) 2023.5 [Reviewed]

DOI Web of Science PubMed

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Joint Work

Tuning of Optical Stopband Wavelength and Effective Bandwidth of Gel-Immobilized Colloidal Photonic Crystal Films

Amano Ami, Kanai Toshimitsu

GELS 9 ( 1 ) 2023.1 [Reviewed]

DOI Web of Science PubMed

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Joint Work

Amorphous photonic structure in a charged colloidal system showing angle-independent uniform color

Kanai, T; Nakagawa, S; Takeshima, H; Hirano, Y

JOURNAL OF COLLOID AND INTERFACE SCIENCE 629 225 - 232 2023.1

DOI Web of Science PubMed Repository

Language：English Publishing type：Research paper (scientific journal) Publisher：Academic Press Inc. Elsevier Science Joint Work

Amorphous photonic structure in a charged colloidal system showing angle-independent uniform color

Kanai Toshimitsu, Nakagawa Sato, Takeshima Hikaru, Hirano Yuna

Journal of Colloid and Interface science 629 225 - 232 2022.9

CiNii Research

Language：English Publishing type：Research paper (scientific journal) Publisher：Academic Press Inc. Elsevier Science Joint Work

Structural colors derived from the scattering or reflection of light by submicron-sized ordered structures are interesting due to their non-fading and tunable colors. Herein we show a colored angle-independent amorphous phase of monodisperse colloids between the crystalline and random phases in a charged col-loidal system. The amorphous photonic structures with low packing density display uniform color over large areas; this is easily altered by adjusting the particle volume fraction. The transmission spectra of amorphous phases display an intersection point at the Bragg wavelength, allowing design of the trans-mission color. We demonstrate that the aqueous suspended colloidal amorphous structures can be immobilized in hydrogel films, while preserving their spectral properties. The sensitivity of the gel to ethanol allows the color to be tuned by changing the ethanol concentration. This angle-independent uni-form color with easy tunability has great potential for application in advanced color materials and sensors.(c) 2022 Elsevier Inc. All rights reserved.

Preparation of monodisperse silica-polyacrylamide hybrid particles with snowman or core-shell morphologies using a microfiuidic device

Nemoto Hikaru, Shimba Daigo, Kanai Toshimitsu

JOURNAL OF ASIAN CERAMIC SOCIETIES 10 ( 2 ) 378 - 385 2022.3 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Joint Work

Generation of Monodisperse Microbubbles with a Controlled Size of Less Than 10 mu m at a Generation Rate on the Order of 10(5) Bubbles/s in Glass Capillary Microfluidic Devices

Kitazaki Risa, Nemoto Hikaru, Kanai Toshimitsu

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 54 ( 10 ) 549 - 556 2021.10 [Reviewed]

DOI Web of Science CiNii Research

Language：English Publishing type：Research paper (scientific journal) Publisher：公益社団法人化学工学会 Joint Work

Inexpensive glass capillary microfluidic devices with co-flow geometry were prepared to generate highly monodispersed microbubbles with a controlled size of less than 10 µm for medical applications. In the analysis, the dimensions of the injection and collection capillaries were decreased, and the gas pressure and liquid phase flow rate were increased to their respective limits. The diameter of the monodisperse microbubbles (having a coefficient of variation of less than 1.5%) could be controlled within the range of 2.4–9.2 µm, while maintaining a generation rate on the order of 105 bubbles/s by adjusting the inner tip diameter of the injection capillary and the liquid phase flow rate. The inner diameter of the collection capillary was 30 µm, and the gas pressure was 0.50 MPa.

Tuning and fixing of uniform Bragg reflection color of gel-immobilized colloidal photonic crystal films

Iwasawa, Y; Tajima, H; Kanai, T

POLYMER JOURNAL 53 ( 10 ) 1157 - 1161 2021.10

DOI Web of Science

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Visualization of Strain Using Elastomer-Immobilized Tunable Colloidal Photonic Crystal Films

AMANO Ami, TAJIMA Hiroyuki, KASAI Naoya, KANAI Toshimitsu

Journal of the Japan Society of Colour Material 94 ( 9 ) 252 - 255 2021.9

DOI CiNii Research

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Colour Material Joint Work

Tunable colloidal photonic crystal films consisting of loosely packed colloidal crystals immobilized in elastomers were prepared. The prepared soft film was adhered to an aluminum specimen and the tensile testing was performed. Before applying the tensile force, the film exhibited red color due to Bragg reflection from (111) lattice planes of the face-centered cubic structure, which are parallel to the film surface. With increasing strain on the specimen, the Bragg wavelength of the colloidal crystals was blue-shifted, mainly owing to reduction of the lattice spacing. Consequently, the color of the film changed to orange, yellow, and green in accordance with increasing strain. The prepared films can be used as simple sensors that detect the strain on the materials to which they are adhered based on color change.

Tuning and fixing of uniform Bragg reflection color of gel-immobilized colloidal photonic crystal films

Iwasawa Yuma, Tajima Hiroyuki, Kanai Toshimitsu

Polymer Journal 53 ( 10 ) 1157 - 1161 2021.6

CiNii Research

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Nature Joint Work

We demonstrate the facile tuning of uniform Bragg reflection color from red to blue by uniaxial compression of gel films containing single-crystalline loosely packed colloidal crystals. The tuned colors can be fixed by photopolymerization of a polymer precursor solution contained in the compressed gel films.

Elastomer-immobilized tunable colloidal photonic crystal films with high optical qualities and high maximum strain

Tajima Hiroyuki, Amano Ami, Kanai Toshimitsu

MATERIALS ADVANCES 2 ( 10 ) 3294 - 3299 2021.4 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Joint Work

Enhanced linear thermosensitivity of gel-immobilized colloidal photonic crystal film bound on glass substrate

Toshimitsu Kanai, Naoto Kobayashi, Hiroyuki Tajima

Materials Advances 2 ( 8 ) 2600 - 2603 2021.3 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Joint Work

Preparation of Monodisperse Submicrometer Soybean Oil Emulsions by Evaporation

Sasaki Hirokazu, Nakatsuka Ayana, Nemoto Hikaru, Kanai Toshimitsu

KAGAKU KOGAKU RONBUNSHU 47 ( 1 ) 7 - 10 2021.1 [Reviewed]

DOI Web of Science CiNii Research

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Society of Chemical Engineers, Japan Joint Work

A mixture of soybean oil and hexane and ultrapure water containing a surfactant were injected into hexane-resistant glass capillary microfluidic devices to generate monodisperse oil/water emulsions. The diameter of the oil droplets was adjusted to be within the range of 2.7–15.6 µm by changing the water phase flow rate. By evaporation of hexane dissolved in the droplets, monodisperse soybean oil emulsions with droplet diameters of 0.5–3.1 µm were prepared. The present method is useful for the preparation of monodisperse emulsions with small droplets and could be used to prepare emulsions with smaller droplets by increasing the hexane concentration.

Other Link： https://ci.nii.ac.jp/naid/130007970882

Preparation of monodisperse hybrid gel particles with various morphologies via flow rate and temperature control

Toshimitsu Kanai, Hiroki Nakai, Ayaka Yamada, Masafumi Fukuyama, David A. Weitz

Soft Matter 2019 ( 15 ) 6934 - 6937 2019.8

DOI

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

Protection against a wide UV wavelength range by Bragg reflection from polycrystalline colloidal photonic crystals

Toshimitsu Kanai, Shinoka Nakashima,Tomomi Oki

Journal of Materials Chemistry C 2019 ( 25 ) 7512 - 7515 2019.7

DOI

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

Co-flow型ガラスキャピラリー製マイクロ流体デバイスによる単分散マイクロバブルの気泡径制御

北崎理沙, 松尾綾, 榛葉大悟, 金井俊光

化学工学論文集 45 ( 1 ) 10 - 15 2019.1 [Reviewed]

DOI

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Enhancement of thermosensitivity of gel-immobilized tunable colloidal photonic crystals with anisotropic contraction

T. Kanai, H. Yano, N. Kobayashi, T. Sawada

ACS Macro Letters 6 ( 11 ) 1196 - 1200 2017.10 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Publisher：ACS Publications Joint Work

Independent control of optical stop-band wavelength and width of colloidal photonic crystals

T. Kanai, K. Sano, H. Yano, T. Sawada

Colloids and Surfaces A 506 586 - 590 2016.10 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER Joint Work

Preparation of monodisperse solid fat microspheres in a microfluidic device

A. Nakatsuka, A. Matsuo, T. Kanai

Journal of Chemical Engineering of Japan 49 ( 6 ) 541 - 543 2016.6 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Joint Work

Microfluidic devices fabricated using stereolithography for preparation of monodisperse double emulsions

T. Kanai, M. Tsuchiya

Chemical Engineering Journal 290 400 - 404 2016.4 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER Joint Work

Spectral Tuning of Gel-Immobilized Colloidal Photonic Crystals

72 ( 10 ) 582 - 589 2015.10 [Reviewed]

DOI

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Crystallization and reentrant melting of charged colloids in nonpolar solvents

T. Kanai, N. Boon, P. Lu, E. Sloutskin, A. Schofield, F. Smallenburg, R. Roij, M. Dijkstra, D. Weitz

Physical Review E 91 ( 3 ) 030301 2015.3 [Reviewed]

DOI

Language：English Publishing type：Research paper (scientific journal) Joint Work

Tunable Properties of Colloidal Photonic Crystals Immobilized in Copolymer Hydrogels in Mixed Solvent

41 ( 1 ) 43 - 47 2015.1 [Reviewed]

DOI

Language：Japanese Publishing type：Research paper (scientific journal) Joint Work

Surface treatment of flow channels in microfluidic devices fabricated by stereolithography

K. Ohtani, M. Tsuchiya, H. Sugiyama, T. Katakura, M. Hayakawa, T. Kanai

Journal of Oleo Science 63 ( 1 ) 93 - 96 2014.1 [Reviewed]

DOI Web of Science

Language：English Publishing type：Research paper (scientific journal) Joint Work

Linear thermosensitivity of gel-immobilized tunable colloidal photonic crystals

H. Sugiyama, T. Sawada, H. Yano, T. Kanai

Journal of Materials Chemistry C 1 ( 38 ) 6103 - 6106 2013.10 [Reviewed]

DOI Web of Science

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

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Papers - KANAI Toshimitsu