Koichi Iwata

Koichi Iwata


Research Focus & Metrics

Academic Career Length

35Years (1992-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 September 2019 in Nature Communications
Verified
Journal Article
Open access
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AGAvijit Ghosh
Avijit Ghosh
MYManabu Yoshida
Manabu Yoshida
KSKouji Suemori
Kouji Suemori
HIHiroaki Isago
Hiroaki Isago
NKNagao Kobayashi
Nagao Kobayashi
TNTakashi Nakanishi
Takashi Nakanishi
Optoelectronically active viscous liquids are ideal for fabricating foldable/stretchable electronics owing to their excellent deformability and predictable π-unit–based optoelectronic functions, which are independent of the device shape and geometry. Here we show, unprecedented ‘liquid electret’ devices that exhibit mechanoelectrical and electroacoustic functions, as well as stretchability, have been prepared using solvent-free liquid porphyrins. The fluidic nature of the free-base alkylated-tetraphenylporphyrins was controlled by attaching flexible and bulky branched alkyl chains at different positions. Furthermore, a subtle porphyrin ring distortion that originated from the bulkiness of alkyl chains was observed. Its consequences on the electronic perturbation of the porphyrin-unit were precisely elucidated by spectroscopic techniques and theoretical modelling. This molecular design allows shielding of the porphyrin unit by insulating alkyl chains, which facilitates its corona-charged state for a long period under ambient conditions.


11 September 2017 in Physical Chemistry Chemical Physics
Verified
Journal Article
Closed access
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BNB. Narayan
B. Narayan
KNK. Nagura
K. Nagura
TTTomohisa Takaya
Tomohisa Takaya
KIKoichi Iwata
Koichi Iwata
ASA. Shinohara
A. Shinohara
TNTakashi Nakanishi
Takashi Nakanishi
Novel alkylated naphthalene liquids with a correlation among the 1- and 2-regioisomeric chemical structures and their photophysical, calorimetric and rheological properties are presented.

13 July 2018 in Macromolecules
Verified
Journal Article
Closed access
TTTomohisa Takaya
Tomohisa Takaya
TOTatsuya Oda
Tatsuya Oda
YSYuki Shibazaki
Yuki Shibazaki
YHYumiko Hayashi
Yumiko Hayashi
HSHiroaki Shimomoto
Hiroaki Shimomoto
KIKoichi Iwata
Koichi Iwata

5 January 2015 in The Analyst
Verified
Journal Article
Closed access
PDF file
ASAshok Zachariah Samuel
Ashok Zachariah Samuel
SYSohshi Yabumoto
Sohshi Yabumoto
KKKenichi Kawamura
Kenichi Kawamura
KIKoichi Iwata
Koichi Iwata
Raman imaging is one of the very informative methods for the characterization of chemically and structurally heterogeneous materials without employing specific molecular labels. Multifocus Raman imaging is one of the fast-imaging alternatives to the conventional single point mapping technique. Since multiple focal points probe the sample simultaneously, this imaging methodology is faster compared to single point mapping. We have further demonstrated the efficiency of this methodology by investigating the morphological features of a porous PMMA film. A Raman image of a 50 × 50 μm2 area was obtained in less than 4 minutes (with a 10 × 10 multifocus configuration). Importantly, a 100 × 100 μm2 area could now be analyzed in minutes while a similar Raman image by single point mapping would take hours to days. Optical sectioning using multifocus Raman imaging reveals unique hierarchical features of the porous polymer thin film. Larger pores are limited to the surface and the inner bulk exhibits characteristic small-pores and an interconnected highly porous morphology. The fast multifocal Raman imaging would be advantageous to the diverse field of scientific disciplines where the speed of image acquisition remains a challenge despite the unparalleled specificity and sensitivity of Raman spectroscopy.

7 October 2020 in The Journal of Organic Chemistry
Verified
Journal Article
Closed access
NNNaoki Noto
Naoki Noto
KTKeigo Takahashi
Keigo Takahashi
SGShion Goryo
Shion Goryo
ATAkira Takakado
Akira Takakado
KIKoichi Iwata
Koichi Iwata
MAMunetaka Akita
Munetaka Akita